All living things are made of cells, and cells are the smallest units that can be alive. Life on Earth is classified into five kingdoms, and they each have their own characteristic kind of cell. However the biggest division is between the cells of the prokaryote kingdom (the bacteria) and those of the other four kingdoms (animals, plants, fungi and protoctista), which are all eukaryotic cells. Prokaryotic cells are smaller and simpler than eukaryotic cells, and do not have a nucleus.

• Prokaryote = without a nucleus
• Eukaryote = with a nucleus

We’ll examine these two kinds of cell in detail, based on structures seen in electron micrographs (photos taken with an electron microscope). These show the individual organelles inside a cell.

Eukaryotic Cells

• Cytoplasm (or Cytosol). This is the solution within the cell membrane. It contains enzymes for metabolic reactions together with sugars, salts, amino acids, nucleotides and everything else needed for the cell to function.
• Nucleus. This is the largest organelle. Surrounded by a nuclear envelope, which is a double membrane with nuclear pores – large holes containing proteins that control the exit of substances such as RNA from the nucleus. The interior is called the nucleoplasm, which is full of chromatin- a DNA/protein complex containing the genes. During cell division the chromatin becomes condensed into discrete observable chromosomes. The nucleolus is a dark region of chromatin, involved in making ribosomes.
• Mitochondrion (pl. Mitochondria). This is a sausage-shaped organelle (8µm long), and is where aerobic respiration takes place in all eukaryotic cells. Mitochondria are surrounded by a double membrane: the outer membrane is simple, while the inner membrane is highly folded into cristae, which give it a large surface area. The space enclosed by the inner membrane is called the matrix, and contains small circular strands of DNA. The inner membrane is studded with stalked particles, which are the site of ATP synthesis.
• Chloroplast. Bigger and fatter than mitochondria, chloroplasts are where photosynthesis takes place, so are only found in photosynthetic organisms (plants and algae). Like mitochondria they are enclosed by a double membrane, but chloroplasts also have a third membrane called the thylakoid membrane. The thylakoid membrane is folded into thylakoid disks, which are then stacked into piles called grana. The space between the inner membrane and the thylakoid is called the stroma. The thylakoid membrane contains chlorophyll and stalked particles, and is the site of photosynthesis and ATP synthesis. Chloroplasts also contain starch grains, ribosomes and circular DNA.
• Ribosomes. These are the smallest and most numerous of the cell organelles, and are the sites of protein synthesis. They are composed of protein and RNA, and are manufactured in the nucleolus of the nucleus. Ribosomes are either found free in the cytoplasm, where they make proteins for the cell’s own use, or they are found attached to the rough endoplasmic reticulum, where they make proteins for export from the cell. They are often found in groups called polysomes. All eukaryotic ribosomes are of the larger, “80S”, type.
• Smooth Endoplasmic Reticulum (SER). Series of membrane channels involved in synthesising and transporting materials, mainly lipids, needed by the cell.
• Rough Endoplasmic Reticulum (RER). Similar to the SER, but studded with numerous ribosomes, which give it its rough appearance. The ribosomes synthesise proteins, which are processed in the RER (e.g. by enzymatically modifying the polypeptide chain, or adding carbohydrates), before being exported from the cell via the Golgi Body.
• Golgi Body (or Golgi Apparatus). Another series of flattened membrane vesicles, formed from the endoplasmic reticulum. Its job is to transport proteins from the RER to the cell membrane for export. Parts of the RER containing proteins fuse with one side of the Golgi body membranes, while at the other side small vesicles bud off and move towards the cell membrane, where they fuse, releasing their contents by exocytosis.
• Vacuoles. These are membrane-bound sacs containing water or dilute solutions of salts and other solutes. Most cells can have small vacuoles that are formed as required, but plant cells usually have one very large permanent vacuole that fills most of the cell, so that the cytoplasm (and everything else) forms a thin layer round the outside. Plant cell vacuoles are filled with cell sap, and are very important in keeping the cell rigid, or turgid. Some unicellular protoctists have feeding vacuoles for digesting food, or contractile vacuoles for expelling water.
• Lysosomes. These are small membrane-bound vesicles formed from the RER containing a cocktail of digestive enzymes. They are used to break down unwanted chemicals, toxins, organelles or even whole cells, so that the materials may be recycled. They can also fuse with a feeding vacuole to digest its contents.
• Cytoskeleton. This is a network of protein fibres extending throughout all eukaryotic cells, used for support, transport and motility. The cytoskeleton is attached to the cell membrane and gives the cell its shape, as well as holding all the organelles in position. There are three types of protein fibres (microfilaments, intermediate filaments and microtubules), and each has a corresponding motor protein that can move along the fibre carrying a cargo such as organelles, chromosomes or other cytoskeleton fibres. These motor proteins are responsible for such actions as: chromosome movement in mitosis, cytoplasm cleavage in cell division, cytoplasmic streaming in plant cells, cilia and flagella movements, cell crawling and even muscle contraction in animals.
• Centriole. This is a pair of short microtubules involved in cell division.
• Cilium and Flagellum. These are flexible tails present in some cells and used for motility. They are an extension of the cytoplasm, surrounded by the cell membrane, and are full of microtubules and motor proteins so are capable of complex swimming movements. There are two kinds: flagella (pl.) (no relation of the bacterial flagellum) are longer than the cell, and there are usually only one or two of them, while cilia (pl.) are identical in structure, but are much smaller and there are usually very many of them.
• Microvilli. These are small finger-like extensions of the cell membrane found in certain cells such as in the epithelial cells of the intestine and kidney, where they increase the surface area for absorption of materials. They are just visible under the light microscope as a brush border.
• Cell Membrane (or Plasma Membrane). This is a thin, flexible layer round the outside of all cells made of phospholipids and proteins. It separates the contents of the cell from the outside environment, and controls the entry and exit of materials. The membrane is examined in detail later.
• Cell Wall. This is a thick layer outside the cell membrane used to give a cell strength and rigidity. Cell walls consist of a network of fibres, which give strength but are freely permeable to solutes (unlike membranes). Plant cell walls are made mainly of cellulose, but can also contain hemicellulose, pectin, lignin and other polysaccharides. There are often channels through plant cell walls called plasmodesmata, which link the cytoplasms of adjacent cells. Fungal cell walls are made of chitin. Animal cells do not have a cell wall.

Prokaryotic Cells

• Cytoplasm. Contains all the enzymes needed for all metabolic reactions, since there are no organelles
• Ribosomes. The smaller (70 S) type.
• Nuclear Zone. The region of the cytoplasm that contains DNA. It is not surrounded by a nuclear membrane.
• DNA. Always circular, and not associated with any proteins to form chromatin.
• Plasmid. Small circles of DNA, used to exchange DNA between bacterial cells, and very useful for genetic engineering.
• Cell membrane. made of phospholipids and proteins, like eukaryotic membranes.
• Mesosome. A tightly-folded region of the cell membrane containing all the membrane-bound proteins required for respiration and photosynthesis.
• Cell Wall. Made of murein, which is a glycoprotein (i.e. a protein/carbohydrate complex). There are two kinds of cell wall, which can be distinguished by a Gram stain: Gram positive bacteria have a thick cell wall and stain purple, while Gram negative bacteria have a thin cell wall with an outer lipid layer and stain pink.
• Capsule (or Slime Layer). A thick polysaccharide layer outside of the cell wall. Used for sticking cells together, as a food reserve, as protection against desiccation and chemicals, and as protection against phagocytosis.
• Flagellum. A rigid rotating helical-shaped tail used for propulsion. The motor is embedded in the cell membrane and is driven by a H⁺ gradient across the membrane. Clockwise rotation drives the cell forwards, while anticlockwise rotation causes a chaotic spin. This is an example of a rotating motor in nature.

Summary of the Differences Between Prokaryotic and Eukaryotic Cells

Endosymbiosis

Prokaryotic cells are far older and more diverse than eukaryotic cells. Prokaryotic cells have probably been around for 3.5 billion years – 2.5 billion years longer than eukaryotic cells. It is thought that eukaryotic cell organelles like mitochondria and chloroplasts are derived from prokaryotic cells that became incorporated inside larger prokaryotic cells. This idea is called endosymbiosis, and is supported by these observations:

• organelles contain circular DNA, like bacteria cells.
• organelles contain 70S ribosomes, like bacteria cells.
• organelles have double membranes, as though a single-membrane cell had been engulfed and surrounded by a larger cell.

The Cell Membrane

The cell membrane (or plasma membrane) surrounds all living cells. It controls how substances can move in and out of the cell and is responsible for many other properties of the cell as well. The membranes that surround the nucleus and other organelles are almost identical to the cell membrane. Membranes are composed of phospholipids, proteins and carbohydrates arranged in a fluid mosaic structure, as shown in this diagram.

The phospholipids form a thin, flexible sheet, while the proteins “float” in the phospholipid sheet like icebergs, and the carbohydrates extend out from the proteins.

The phospholipids are arranged in a bilayer, with their polar, hydrophilic phosphate heads facing outwards, and their non-polar, hydrophobic fatty acid tails facing each other in the middle of the bilayer. This hydrophobic layer acts as a barrier to all but the smallest molecules, effectively isolating the two sides of the membrane. Different kinds of membranes can contain phospholipids with different fatty acids, affecting the strength and flexibility of the membrane, and animal cell membranes also contain cholesterol linking the fatty acids together and so stabilising and strengthening the membrane.

The proteins usually span from one side of the phospholipid bilayer to the other (intrinsic proteins), but can also sit on one of the surfaces (extrinsic proteins). They can slide around the membrane very quickly and collide with each other, but can never flip from one side to the other. The proteins have hydrophilic amino acids in contact with the water on the outside of membranes, and hydrophobic amino acids in contact with the fatty chains inside the membrane. Proteins comprise about 50% of the mass of membranes, and are responsible for most of the membrane’s properties.

• Proteins that span the membrane are usually involved in transporting substances across the membrane (more details below).
• Proteins on the inside surface of cell membranes are often attached to the cytoskeleton and are involved in maintaining the cell’s shape, or in cell motility. They may also be enzymes, catalysing reactions in the cytoplasm.
• Proteins on the outside surface of cell membranes can act as receptors by having a specific binding site where hormones or other chemicals can bind. This binding then triggers other events in the cell. They may also be involved in cell signalling and cell recognition, or they may be enzymes, such as maltase in the small intestine (more in digestion).

The carbohydrates are found on the outer surface of all eukaryotic cell membranes, and are usually attached to the membrane proteins. Proteins with carbohydrates attached are called glycoproteins. The carbohydrates are short polysaccharides composed of a variety of different monosaccharides, and form a cell coat or glycocalyx outside the cell membrane. The glycocalyx is involved in protection and cell recognition, and antigens such as the ABO antigens on blood cells are usually cell-surface glycoproteins.

Remember that a membrane is not just a lipid bilayer, but comprises the lipid, protein and carbohydrate parts.

Transport Across The Membrane

Cell membranes are a barrier to most substances, and this property allows materials to be concentrated inside cells, excluded from cells, or simply separated from the outside environment. This is compartmentalization is essential for life, as it enables reactions to take place that would otherwise be impossible. Eukaryotic cells can also compartmentalize materials inside organelles. Obviously materials need to be able to enter and leave cells, and there are five main methods by which substances can move across a cell membrane:

• 1. Simple Diffusion
• 2. Osmosis
• 3. Facilitated Diffusion
• 4. Active Transport
• 5. Vesicles

1. Simple Diffusion

A few substances can diffuse directly through the lipid bilayer part of the membrane. The only substances that can do this are lipid-soluble molecules such as steroids, or very small molecules, such as H₂O, O₂ and CO₂. For these molecules the membrane is no barrier at all. Since lipid diffusion is (obviously) a passive diffusion process, no energy is involved and substances can only move down their concentration gradient. Lipid diffusion cannot be controlled by the cell, in the sense of being switched on or off.

2. Osmosis

Osmosis is the diffusion of water across a membrane. It is in fact just normal lipid diffusion, but since water is so important and so abundant in cells (its concentration is about 50 M), the diffusion of water has its own name – osmosis. The contents of cells are essentially solutions of numerous different solutes, and the more concentrated the solution, the more solute molecules there are in a given volume, so the fewer water molecules there are. Water molecules can diffuse freely across a membrane, but always down their concentration gradient, so water therefore diffuses from a dilute to a concentrated solution.

Water Potential. Osmosis can be quantified using water potential, so we can calculate which way water will move, and how fast. Water potential (Y, the Greek letter psi, pronounced “sy”) is a measure of the water molecule potential for movement in a solution. It is measured in units of pressure (Pa, or usually kPa), and the rule is that water always moves by osmosis from less negative to more negative water potential (in other words it’s a bit like gravity potential or electrical potential). 100% pure water has Y = 0, which is the highest possible water potential, so all solutions have Y < 0 (i.e. a negative number), and you cannot get Y > 0.

Cells and Osmosis. The concentration (or OP) of the solution that surrounds a cell will affect the state of the cell, due to osmosis. There are three possible concentrations of solution to consider:

• Isotonic solution a solution of equal OP (or concentration) to a cell
• Hypertonic solution a solution of higher OP (or concentration) than a cell
• Hypotonic solution a solution of lower OP (or concentration) than a cell
• The effects of these solutions on cells are shown in this diagram:

The diagram below shows what happens when 2 fresh raw eggs with their shells removed with acid are placed into sucrose solution (hypertonic) and distilled water (hypotonic). Water enters the egg in water (endosmosis) causing it to swell and water leaves the egg in sucrose causing it to shrink (exosmosis).

These are problems that living cells face all the time. For example:

• Simple animal cells (protozoans) in fresh water habitats are surrounded by a hypotonic solution and constantly need to expel water using contractile vacuoles to prevent swelling and lysis.
• Cells in marine environments are surrounded by a hypertonic solution, and must actively pump ions into their cells to reduce their water potential and so reduce water loss by osmosis.
• Young non-woody plants rely on cell turgor for their support, and without enough water they wilt. Plants take up water through their root hair cells by osmosis, and must actively pump ions into their cells to keep them hypertonic compared to the soil. This is particularly difficult for plants rooted in salt water.

3. Facilitated Diffusion.

Facilitated diffusion is the transport of substances across a membrane by a trans-membrane protein molecule. The transport proteins tend to be specific for one molecule (a bit like enzymes), so substances can only cross a membrane if it contains the appropriate protein. As the name suggests, this is a passive diffusion process, so no energy is involved and substances can only move down their concentration gradient. There are two kinds of transport protein:

• Channel Proteins form a water-filled pore or channel in the membrane. This allows charged substances (usually ions) to diffuse across membranes. Most channels can be gated (opened or closed), allowing the cell to control the entry and exit of ions.
• Carrier Proteins have a binding site for a specific solute and constantly flip between two states so that the site is alternately open to opposite sides of the membrane. The substance will bind on the side where it at a high concentration and be released where it is at a low concentration.

The rate of diffusion of a substance across a membrane increases as its concentration gradient increases, but whereas lipid diffusion shows a linear relationship, facilitated diffusion has a curved relationship with a maximum rate. This is due to the rate being limited by the number of transport proteins.

4. Active Transport (or Pumping).

Active transport is the pumping of substances across a membrane by a trans-membrane protein pump molecule. The protein binds a molecule of the substance to be transported on one side of the membrane, changes shape, and releases it on the other side. The proteins are highly specific, so there is a different protein pump for each molecule to be transported. The protein pumps are also ATPase enzymes, since they catalyse the splitting of ATP into ADP + phosphate (Pi), and use the energy released to change shape and pump the molecule. Pumping is therefore an active process, and is the only transport mechanism that can transport substances up their concentration gradient.

The Na⁺K⁺ Pump. This transport protein is present in the cell membranes of all animal cells and is the most abundant and important of all membrane pumps. We look at it in more detail in module 4 (A2 course)

5. Vesicles

The processes described so far only apply to small molecules. Large molecules (such as proteins, polysaccharides and nucleotides) and even whole cells are moved in and out of cells by using membrane vesicles.

Endocytosis is the transport of materials into a cell. Materials are enclosed by a fold of the cell membrane, which then pinches shut to form a closed vesicle. Strictly speaking the material has not yet crossed the membrane, so it is usually digested and the small product molecules are absorbed by the methods above. When the materials and the vesicles are small (such as a protein molecule) the process is known as pinocytosis (cell drinking), and if the materials are large (such as a white blood cell ingesting a bacterial cell) the process is known as phagocytosis (cell eating).

Exocytosis is the transport of materials out of a cell. It is the exact reverse of endocytosis. Materials to be exported must first be enclosed in a membrane vesicle, usually from the RER and Golgi Body. Hormones and digestive enzymes are secreted by exocytosis from the secretory cells of the intestine and endocrine glands.

Sometimes materials can pass straight through cells without ever making contact with the cytoplasm by being taken in by endocytosis at one end of a cell and passing out by exocytosis at the other end.

BIOCHEMISTRY

At least 80% of the mass of living organisms is water, and almost all the chemical reactions of life take place in aqueous solution. The other chemicals that make up living things are mostly organic macromolecules belonging to the 4 groups proteins, nucleic acids, carbohydrates or lipids. These macromolecules are made up from specific monomers as shown in the table below. Between them these four groups make up 93% of the dry mass of living organisms, the remaining 7% comprising small organic molecules (like vitamins) and inorganic ions.

The first part of this unit is about each of these groups. We’ll look at each of these groups in detail, except nucleic acids, which are studied in module 2.

WATER

Water molecules are charged, with the oxygen atom being slightly negative and the hydrogen atoms being slightly positive. These opposite charges attract each other, forming hydrogen bonds. These are weak, long distance bonds that are very common and very important in biology.

Water has a number of important properties essential for life. Many of the properties below are due to the hydrogen bonds in water.

• Solvent. Because it is charged, water is a very good solvent. Charged or polar molecules such as salts, sugars and amino acids dissolve readily in water and so are called hydrophilic (“water loving”). Uncharged or non-polar molecules such as lipids do not dissolve so well in water and are called hydrophobic (“water hating”).
• Specific heat capacity. Water has a specific heat capacity of 4.2 J g^-1 °C^-1, which means that it takes 4.2 joules of energy to heat 1 g of water by 1°C. This is unusually high and it means that water does not change temperature very easily. This minimizes fluctuations in temperature inside cells, and it also means that sea temperature is remarkably constant.
• Latent heat of evaporation. Water requires a lot of energy to change state from a liquid into a gas, and this is made use of as a cooling mechanism in animals (sweating and panting) and plants (transpiration). As water evaporates it extracts heat from around it, cooling the organism.
• Density. Water is unique in that the solid state (ice) is less dense that the liquid state, so ice floats on water. As the air temperature cools, bodies of water freeze from the surface, forming a layer of ice with liquid water underneath. This allows aquatic ecosystems to exist even in sub-zero temperatures.
• Cohesion. Water molecules “stick together” due to their hydrogen bonds, so water has high cohesion. This explains why long columns of water can be sucked up tall trees by transpiration without breaking. It also explains surface tension, which allows small animals to walk on water.
• Ionization. When many salts dissolve in water they ionize into discrete positive and negative ions (e.g. NaCl Na⁺ + Cl^-). Many important biological molecules are weak acids, which also ionize in solution (e.g. acetic acid acetate^- + H⁺). The names of the acid and ionized forms (acetic acid and acetate in this example) are often used loosely and interchangeably, which can cause confusion. You will come across many examples of two names referring to the same substance, e.g.: phosphoric acid and phosphate, lactic acid and lactate, citric acid and citrate, pyruvic acid and pyruvate, aspartic acid and aspartate, etc. The ionized form is the one found in living cells.
• pH. Water itself is partly ionized (H₂O H⁺ + OH^- ), so it is a source of protons (H⁺ ions), and indeed many biochemical reactions are sensitive to pH (-log[H⁺]). Pure water cannot buffer changes in H⁺ concentration, so is not a buffer and can easily be any pH, but the cytoplasms and tissue fluids of living organisms are usually well buffered at about neutral pH (pH 7-8).

CARBOHYDRATES

Carbohydrates contain only the elements carbon, hydrogen and oxygen. The group includes monomers, dimers and polymers, as shown in this diagram:

Monosaccharides

All have the formula (CH₂O)_n, where n is between 3 and 7. The most common & important monosaccharide is glucose, which is a six-carbon sugar. It’s formula is C₆H₁₂O₆ and its structure is shown below

or more simply

Glucose forms a six-sided ring. The six carbon atoms are numbered as shown, so we can refer to individual carbon atoms in the structure. In animals glucose is the main transport sugar in the blood, and its concentration in the blood is carefully controlled.

There are many monosaccharides, with the same chemical formula (C₆H₁₂O₆), but different structural formulae. These include fructose and galactose.

Common five-carbon sugars (where n = 5, C₅H₁₀O₅) include ribose and deoxyribose (found in nucleic acids and ATP).

Disaccharides

Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond. The reaction involves the formation of a molecule of water (H₂O):

This shows two glucose molecules joining together to form the disaccharide maltose. Because this bond is between carbon 1 of one molecule and carbon 4 of the other molecule it is called a 1-4 glycosidic bond. This kind of reaction, where water is formed, is called a condensation reaction. The reverse process, when bonds are broken by the addition of water (e.g. in digestion), is called a hydrolysis reaction.

• polymerisation reactions are condensation reactions
• breakdown reactions are hydrolysis reactions

There are three common disaccharides:

• Maltose (or malt sugar) is glucose & glucose. It is formed on digestion of starch by amylase, because this enzyme breaks starch down into two-glucose units. Brewing beer starts with malt, which is a maltose solution made from germinated barley. Maltose is the structure shown above.
• Sucrose (or cane sugar) is glucose & fructose. It is common in plants because it is less reactive than glucose, and it is their main transport sugar. It’s the common table sugar that you put in tea.
• Lactose (or milk sugar) is galactose & glucose. It is found only in mammalian milk, and is the main source of energy for infant mammals.

Polysaccharides

Polysaccharides are long chains of many monosaccharides joined together by glycosidic bonds. There are three important polysaccharides:

Starch is the plant storage polysaccharide. It is insoluble and forms starch granules inside many plant cells. Being insoluble means starch does not change the water potential of cells, so does not cause the cells to take up water by osmosis (more on osmosis later). It is not a pure substance, but is a mixture of amylose and amylopectin.

Amylose is simply poly-(1-4) glucose, so is a straight chain. In fact the chain is floppy, and it tends to coil up into a helix.
Amylopectin is poly(1-4) glucose with about 4% (1-6) branches. This gives it a more open molecular structure than amylose. Because it has more ends, it can be broken more quickly than amylose by amylase enzymes.

Both amylose and amylopectin are broken down by the enzyme amylase into maltose, though at different rates.

Glycogen is similar in structure to amylopectin. It is poly (1-4) glucose with 9% (1-6) branches. It is made by animals as their storage polysaccharide, and is found mainly in muscle and liver. Because it is so highly branched, it can be mobilised (broken down to glucose for energy) very quickly.

Cellulose is only found in plants, where it is the main component of cell walls. It is poly (1-4) glucose, but with a different isomer of glucose. Cellulose contains beta-glucose, in which the hydroxyl group on carbon 1 sticks up. This means that in a chain alternate glucose molecules are inverted.

This apparently tiny difference makes a huge difference in structure and properties. While the a1-4 glucose polymer in starch coils up to form granules, the beta1-4 glucose polymer in cellulose forms straight chains. Hundreds of these chains are linked together by hydrogen bonds to form cellulose microfibrils. These microfibrils are very strong and rigid, and give strength to plant cells, and therefore to young plants.

The beta-glycosidic bond cannot be broken by amylase, but requires a specific cellulase enzyme. The only organisms that possess a cellulase enzyme are bacteria, so herbivorous animals, like cows and termites whose diet is mainly cellulose, have mutualistic bacteria in their guts so that they can digest cellulose. Humans cannot digest cellulose, and it is referred to as fibre.

Other polysaccharides that you may come across include:

• Chitin (poly glucose amine), found in fungal cell walls and the exoskeletons of insects.
• Pectin (poly galactose uronate), found in plant cell walls.
• Agar (poly galactose sulphate), found in algae and used to make agar plates.
• Murein (a sugar-peptide polymer), found in bacterial cell walls.
• Lignin (a complex polymer), found in the walls of xylem cells, is the main component of wood.

LIPIDS

Lipids are a mixed group of hydrophobic compounds composed of the elements carbon, hydrogen and oxygen. They contain fats and oils (fats are solid at room temperature, whereas oils are liquid)

Triglycerides

Triglycerides are commonly called fats or oils. They are made of glycerol and fatty acids.

Glycerol is a small, 3-carbon molecule with three hydroxyl groups.
Fatty acids are long molecules with a polar, hydrophilic end and a non-polar, hydrophobic “tail”. The hydrocarbon chain can be from 14 to 22 CH2 units long. The hydrocarbon chain is sometimes called an R group, so the formula of a fatty acid can be written as R-COOH.

• If there are no C=C double bonds in the hydrocarbon chain, then it is a saturated fatty acid (i.e. saturated with hydrogen). These fatty acids form straight chains, and have a high melting point.

• If there are C=C double bonds in the hydrocarbon chain, then it is an unsaturated fatty acid (i.e. unsaturated with hydrogen). These fatty acids form bent chains, and have a low melting point. Fatty acids with more than one double bond are called poly-unsaturated fatty acids (PUFAs).

One molecule of glycerol joins togther with three fatty acid molecules to form a triglyceride molecule, in another condensation polymerisation reaction:

Triglycerides are insoluble in water. They are used for storage, insulation and protection in fatty tissue (or adipose tissue) found under the skin (sub-cutaneous) or surrounding organs. They yield more energy per unit mass than other compounds so are good for energy storage. Carbohydrates can be mobilised more quickly, and glycogen is stored in muscles and liver for immediate energy requirements.

• Triglycerides containing saturated fatty acids have a high melting point and tend to be found in warm-blooded animals. At room temperature they are solids (fats), e.g. butter, lard.
• Triglycerides containing unsaturated fatty acids have a low melting point and tend to be found in cold-blooded animals and plants. At room temperature they are liquids (oils), e.g. fish oil, vegetable oils.

Phospholipids

Phospholipids have a similar structure to triglycerides, but with a phosphate group in place of one fatty acid chain. There may also be other groups attached to the phosphate. Phospholipids have a polar hydrophilic “head” (the negatively-charged phosphate group) and two non-polar hydrophobic “tails” (the fatty acid chains). This mixture of properties is fundamental to biology, for phospholipids are the main components of cell membranes.

When mixed with water, phospholipids form droplet spheres with the hydrophilic heads facing the water and the hydrophobic tails facing each other. This is called a micelle.
Alternatively, they may form a double-layered phospholipid bilayer. This traps a compartment of water in the middle separated from the external water by the hydrophobic sphere. This naturally-occurring structure is called a liposome, and is similar to a membrane surrounding a cell.

Waxes

Waxes are formed from fatty acids and long-chain alcohols. They are commonly found wherever waterproofing is needed, such as in leaf cuticles, insect exoskeletons, birds’ feathers and mammals’ fur.

Steroids

Steroids are small hydrophobic molecules found mainly in animals. They include:

• cholesterol, which is found in animals cell membranes to increase stiffness
• bile salts, which help to emulsify dietary fats
• steroid hormones such as testosterone, oestrogen, progesterone and cortisol
• vitamin D, which aids Ca²⁺ uptake by bones.

PROTEINS

Proteins are the most complex and most diverse group of biological compounds. They have an astonishing range of different functions, as this list shows.

• structure e.g. collagen (bone, cartilage, tendon), keratin (hair), actin (muscle)
• enzymes e.g. amylase, pepsin, catalase, etc (>10,000 others)
• transport e.g. haemoglobin (oxygen), transferrin (iron)
• pumps e.g. Na⁺K⁺ pump in cell membranes
• motors e.g. myosin (muscle), kinesin (cilia)
• hormones e.g. insulin, glucagon
• receptors e.g. rhodopsin (light receptor in retina)
• antibodies e.g. immunoglobulins
• storage e.g. albumins in eggs and blood, caesin in milk
• blood clotting e.g. thrombin, fibrin
• lubrication e.g. glycoproteins in synovial fluid
• toxins e.g. diphtheria toxin
• antifreeze e.g. glycoproteins in arctic flea
• and many more!

Proteins are made of amino acids. Amino acids are made of the five elements C H O N S. The general structure of an amino acid molecule is shown on the right. There is a central carbon atom (called the “alpha carbon”), with four different chemical groups attached to it:

• a hydrogen atom
• a basic amino group
• an acidic carboxyl group
• a variable “R” group (or side chain)

Amino acids are so-called because they have both amino groups and acid groups, which have opposite charges. At neutral pH (found in most living organisms), the groups are ionized as shown above, so there is a positive charge at one end of the molecule and a negative charge at the other end. The overall net charge on the molecule is therefore zero. A molecule like this, with both positive and negative charges is called a zwitterion. The charge on the amino acid changes with pH:

low pH (acid)	neutral pH	high pH (alkali)
charge = +1	charge = 0	charge = -1

It is these changes in charge with pH that explain the effect of pH on enzymes. A solid, crystallised amino acid has the uncharged structure

however this form never exists in solution, and therefore doesn’t exist in living things (although it is the form usually given in textbooks).

There are 20 different R groups, and so 20 different amino acids. Since each R group is slightly different, each amino acid has different properties, and this in turn means that proteins can have a wide range of properties. The following table shows the 20 different R groups, grouped by property, which gives an idea of the range of properties. You do not need to learn these, but it is interesting to see the different structures, and you should be familiar with the amino acid names. You may already have heard of some, such as the food additive monosodium glutamate, which is simply the sodium salt of the amino acid glutamate. Be careful not to confuse the names of amino acids with those of bases in DNA, such as cysteine (amino acid) and cytosine (base), threonine (amino acid) and thymine (base). There are 3-letter and 1-letter abbreviations for each amino acid.

The Twenty Amino Acid R-Groups (for interest only no knowledge required)
	Simple R groups		Basic R groups
Glycine Gly G		Lysine Lys K
Alanine Ala A		Arginine Arg R
Valine Val V		Histidine His H
Leucine Leu L		Asparagine Asn N
Isoleucine Ile I		Glutamine Gln Q
	Hydroxyl R groups		Acidic R groups
Serine Ser S		Aspartate Asp D
Threonine Thr T		Glutamate Glu E
	Sulphur R groups		Ringed R groups
Cysteine Cys C		Phenylalanine Phe F
Methionine Met M		Tyrosine Tyr Y
	Cyclic R group
Proline Pro P		Tryptophan Trp W

Polypeptides

Amino acids are joined together by peptide bonds. The reaction involves the formation of a molecule of water in another condensation polymerisation reaction:

When two amino acids join together a dipeptide is formed. Three amino acids form a tripeptide. Many amino acids form a polypeptide. e.g.:

⁺NH₃-Gly — Pro — His — Leu — Tyr — Ser — Trp — Asp — Lys — Cys-COO^-

In a polypeptide there is always one end with a free amino (NH₂) (NH₃ in solution) group, called the N-terminus, and one end with a free carboxyl (COOH) (COO in solution)  group, called the C-terminus.

Protein Structure

Polypeptides are just a string of amino acids, but they fold up to form the complex and well-defined three-dimensional structure of working proteins. To help to understand protein structure, it is broken down into four levels:

1. Primary Structure

2. Secondary Structure

The a-helix. The polypeptide chain is wound round to form a helix. It is held together by hydrogen bonds running parallel with the long helical axis. There are so many hydrogen bonds that this is a very stable and strong structure. Helices are common structures throughout biology.
The b-sheet. The polypeptide chain zig-zags back and forward forming a sheet. Once again it is held together by hydrogen bonds.

3. Tertiary Structure

• hydrogen bonds, which are weak.
• ionic bonds between R-groups with positive or negative charges, which are quite strong.
• sulphur bridges – covalent S-S bonds between two cysteine amino acids, which are strong.

4. Quaternary Structure

Haemoglobin, the oxygen-carrying protein in red blood cells, consists of four globular subunits arranged in a tetrahedral (pyramid) structure. Each subunit contains one iron atom and can bind one molecule of oxygen.

These four structures are not real stages in the formation of a protein, but are simply a convenient classification that scientists invented to help them to understand proteins. In fact proteins fold into all these structures at the same time, as they are synthesised.

The final three-dimensional shape of a protein can be classified as globular or fibrous.

globular structure

fibrous (or filamentous) structure

The vast majority of proteins are globular, including enzymes, membrane proteins, receptors, storage proteins, etc. Fibrous proteins look like ropes and tend to have structural roles such as collagen (bone), keratin (hair), tubulin (cytoskeleton) and actin (muscle). They are usually composed of many polypeptide chains. A few proteins have both structures: the muscle protein myosin has a long fibrous tail and a globular head, which acts as an enzyme.

BREAST EXAMINATION

Anatomy: The breast is made up of milk producing glands that are arranged into units known as lobules. These glands are connected via a series of ducts that ultimately join up to form a common drainage path, terminating at the nipple. The nipple is surrounded by a ring of pigmented tissue known as the areola. Fibro-elastic and fatty tissue provide support for the rest of the structure and allow the breast to maintain its distinctive shape. The breast lies on top of the pectoral muscle, which in turn rests on the thoracic cage. Rough boundaries of the breast are as follows:

1. Superior aspect of the breast is bounded by the clavicle
2. Inferiorly by the inframamary crease (“bra line”)
3. Medially by the sternum
4. Laterally by the axilla

Each breast contains a network of lymphatic tissue, ~ 90% of which drain into a lymph node group found in the ipsilateral axilla. The remaining 10% drain into the Internal Thoracic nodes, which are located beneath the sternum (not accessible by exam). Lymph drainage pathways are important in the setting of breast cancer, as this is usually the first site of spread (see below). For obvious reasons (i.e., milk production) woman have significantly more breast tissue then men. 

Assorted images of the breast–NIH  

Basic breast anatomy and info on breast cancer, The cancer council Victoria, Australia. 

Why and when should a breast examination be performed? 

In the asymptomatic patient: The asymptomatic breast exam is generally performed only on women. This is because diseases of the breast, in particular cancer, occur far more commonly in women then men. Malignancies generally originate in either the glandular tissues that secrete milk or in the ductal structures that transport it to the nipple. 

Examination can be done by the clinician (Clinical Breast Exam – CBE) or patient (Self Breast Exam – SBE). Those performed by the clinician are usually done on an annual basis, beginning at the age of 40, which coincides with time of increased risk for development of breast cancer. Other major breast cancer risk factors include: prior history of breast ca, family history in 1st degree relative (particularly if at a young age), increasing patient age and features that result in prolonged/uninterrupted exposure to estrogen (e.g. early age at onset menstruation, never having been pregnant, older age at first pregnancy, older age at menopause). SBE is often recommended on a monthly-to-every-few-months basis. 

Interestingly, while both SBE and CBE are part of routine clinical care, there are no studies that demonstrate that either of these techniques, when performed as stand-alone examinations, actually improves clinical outcomes (i.e. detects cancer at an earlier stage, demonstrating positive impact on cancer related morbidity or mortality). In contrast, mammography (performed with or without CBE), has a strong body of evidence to support its routine use as a screening tool for early detection of malignancy. 

In the symptomatic patient: The goal of the examination in the setting of symptoms is to better characterize the abnormality, identify underlying etiology, and direct additional evaluation and treatment. Breast related symptoms may include any of the following:

• Discrete masses detected by the patient, often concerning for malignancy
• Pain, which can be associated with a number of processes including: cyclical in a menstruating women (reflecting transient hormone induced changes in the breast tissue), occasionally malignancies.
• Unusual nipple discharge, which may include:
  • Blood, concerning for malignancy
  • Milk when not pregnant. Suggestive inappropriate Prolactin secretion from the pituitary – may also be induced by certain medications
  • Other
• Discoloration or change in the quality of the skin:
  • Redness suggests infection or inflammation – in the post partum patient, this is often due to mastitis, a diffuse inflammatory condition caused by congestion from inadequately expressed milk.
  • “Peau d’orange” quality – an “Orange Peel” like texture that’s caused by an uncommon, aggressive inflammatory malignancy

If a mass or other abnormality is identified, it’s location can be described as being in one of 4 quadrants (left upper, left lower, right upper, right lower) of the breast. Alternatively, it can be described relative to it’s position, imagining a clock face were superimposed on the breast. 

It’s worth noting that breast symptoms may be caused by diseases elsewhere in the body. For example, as mentioned above, inappropriate milk production may be due to a pituitary tumor secreting Prolactin. Or breast development in men may signify underlying liver disease. Given this, breast symptoms may merit careful history and evaluation of other organ systems. As symptoms can occur in male or female patients (though overall, female >>> male), evaluation is indicated in either sex patient who presents with breast concerns. 

Examination in Detail

Getting Started

1. Carefully explain what you are going to do – and why.
2. Room should be a comfortable temperature.
3. Patient should be in a gown – all undergarments (bras, shirts, etc) should be removed.
4. Have the patient remove their arms from the sleeves of the gown – though keep both breasts covered by laying the garment on top of their chest. Alternatively, the patient may put on the gown so that it opens in the front, which may make exposing one breast at a time a bit easier.
5. Patient should be lying flat on the table – It may help to have them place hand on side to be examined behind their head, allowing easier access to breast and axilla.
6. Uncover only the breast that you are going to examine.
7. Observe the breast, looking for evidence of skin or nipple dimpling/retraction, discoloration, obvious masses or asymmetry.
8. Observing the breasts while the patient sits up may increase your ability to detect asymmetry or other surface abnormalities, particularly if the person has large breasts.

Palpation of the Breast and Axilla: The goal of this exam is to examine the breast in a systematic fashion, such that all of the tissue is palpated. 3 methods are described below. The accuracy of the exam is increased by allowing adequate time. This will vary with breast size. Specifically, it will take more time to carefully evaluate larger breasts. Regardless of the method used to assure that the breast is examined in its entirety, palpation technique should be as follows:

Palpation Technique in Detail

1. Use the pads of the middle 3 fingers of one hand.
2. Press downward using a circular motion.
3. Apply steady pressure, pushing down to the level of the chest wall. Apply enough pressure to palpate to 3 levels of depth: first superficial, then medium, and then deep/to the level of the chest wall.
4. Make sure to palpate the nipple and areolar regions.

What precisely are you trying to identify? Normal breasts have a lumpy consistency, created by the mix of lobular, ductal and supporting tissue. The CBE (as mentioned above) is largely performed to identify masses consistent with malignancy. Most lumps are benign (e.g. fibroadenomas, cysts). Masses of concern tend to have the following characteristics: Feel different from the rest of the breast tissue (aka “dominant mass”), firmness, irregular/hard to define borders, fixed/stuck to adjacent tissue – and increase in size over time. As breast density decreases with age (lobular tissue replaced by fat), it is easier to identify masses in older patients.

Three Methods for systematic examination of the breast:

Method 1 – Vertical strips:

1. In this technique, you are breaking the breast into a series of vertical strips, each of which is evaluated sequentially, moving lateral to medial.
2. Start at the clavicle, adjacent to the axilla.
3. Move your hand down in a vertical line until you’ve reached the area below the breast. Actual palpation technique is as described above.
4. Then move a bit more medially, and examine while traveling up towards the top of the breast.
5. When you reach the clavicle, move medially and repeat until you’ve evaluated the entire breast.
6. There is a “tail” of breast tissue that extends from the lateral aspect of the structure towards the axilla. Make sure that you palpate this region as well.

Method 2 – Pie or Radial Spoke Pattern:

1. Imagine that the breast is broken into a series of pie-type slices, with the nipple at the center.
2. Start at the nipple, working outwards toward the periphery of the slice that you’re examining. Move your hands a few centimeters along each time.
3. When you are clearly no longer over the breast, move to the next slice
4. Make sure that you palpate the “tail” of the breast as described above.

Method 3 – Circular Pattern:

1. Start at the nipple.
2. Work along in circular fashion, moving in a spiral towards the periphery.
3. Make sure that you palpate the “tail” of the breast as described in above.

Following direct palpation of the breast, the axillary region should be palpated. This is because the axillary lymph nodes are usually the first site of spread in the setting of breast cancer. While this is of greatest importance when you identify a concerning mass in the breast itself, include the axilla in all of your breast exams. To examine, proceed as follows:

1. It may help to have the patient lower their arm so it is next to their side, as when the hand is behind their head, the axillary skin is taught and perhaps more difficult to palpate thru.
2. Gently move the arm 20-30 cm away from the patient’s body, so that you can gain access to the axillary region.
3. Direct the finger tips of the examining hand (it’s a bit easier to use your L hand when examining the R breast, and vice versa) toward the top of the axilla.
4. Then push the palmar aspect of the hand towards the chest wall. You are trying to identify any abnormal nodules/lumps that could represent axillary adenopathy. In addition, you may be able to trap the nodes between your hand and the chest wall, which can then be better characterized.
5. Most women will not have palpable axillary lymph nodes. If you do feel discrete masses, make note of: firmness, quantity and degree of mobility. In general, malignancy is associated with: firmness, increased quantity, adherence to each other and/or the chest wall.
6. Recognize that adenopathy may not be due to breast disease. For example, infections of the hand can cause acute, painful axillary adenopathy. Similarly, systemic diseases (e.g. lymphoma, sarcoidosis) may also cause lymph node enlargement. Thus, as with all other aspects of the exam, history and findings in other regions are of great importance.

The other breast is then examined. 

Additional aspects of the exam that can be performed:

1. Assessment of nipple discharge: If the patient reports unusual discharge from the nipple, gently palpate the breast near the nipple, with a goal of trying to express and examine any abnormal fluid. Bloody discharge is particularly concerning for cancer. Most discharge, however, will be secondary to benign conditions.
2. Puckering/Dimpling: This can suggest an underlying mass which is distorting the skin above it. In this setting, careful palpation around the dimpling is often revealing. In addition, if it’s unclear if there is dimpling or asymmetry, observe the breasts while the patient sits up (with hands placed on hips). This may help clarify differences between the 2 sides and accentuate asymmetry.
3. Nipple Retraction: This is concerning for a mass growing underneath the nipple. In this case, carefully palpate the tissue around and underneath the nipple. 
4. Redness/Pain: Suggestive of inflammation and/or infection. Carefully note the extent of redness as well as temperature differences. Assess for any focal swelling or fluctuance that might suggest underlying abscess.

Pitfalls and Problem Areas: 

1. Examining women with large breasts: In this setting, it can be technically challenging to assure that you’ve done a thorough examination of all the tissue. In order to minimize error there no special “tricks.” Instead, rely on basic exam principles, in particular: Take your time – may take 3 or minutes to examine each breast! Be thorough and ordered, covering all areas of the breast sequentially.
2. Careful evaluation of masses: There are many anecdotes relating to missed diagnoses of breast cancer. I recognize that all masses do not represent malignancy. In fact, most are benign (e.g. secondary to fibro-cystic changes, cysts, transient changes that vary with time of the menstrual cycle, etc). An array of thoughtful reviews have been written that describe the appropriate evaluation of abnormal findings. Specifically: when to evaluate with ultrasound, when to consider aspiration, when to consider biopsy, when to re-evaluate at a different point in the menstrual cycle (greatest amount of swelling is usually immediately prior to menstruation), when to refer, etc.. The comments which follow are not meant to contradict this information. Nor are they particularly applicable to those with clear expertise in the appropriate evaluation of abnormal exam findings.What follows is directed to the more novice examiner:
   • If you clearly identify a discrete mass, consider it to be malignant until proven otherwise. In general, determination of final diagnosis requires a biopsy.
   • A dominant breast mass that does not have a corresponding abnormality on Mammogram (i.e. “normal mammo”) should still be considered malignant until proven otherwise. This is because not all malignancies generate mammographic findings.
   • While uncommon, breast cancer can occur in men. Thus, discrete masses should be appropriately evaluated.
   • Breast cancer can occur in young women (20s and 30s) �thus worrisome masses in this population should be appropriately evaluated.
   • If you have any concerns or uncertainty re any exam finding, seek input from someone with appropriate experience and training.
3. Pay very careful attention to any mass that the patient brings to your attention. Women who are good self-examiners can often detect subtle/early changes concerning for malignancy that an examiner may have difficulty identifying.

Assorted basic information about breast cancer, NIH site. 

More information about breast cancer, NCI Site 

Gail Model for calculating breast CA risk – NCI

This information was tagged from http://meded.ucsd.edu/clinicalmed/breast.htm#Anatomy and is copyrighted by its original owner. Content is not owned or is an originality of Easysemester.com

You are to give 30 mg. of Inderal. The available dosage strength is a scored 60mg. tablet. What amount will you give?

Here is the correct answer:
1/2 tablets

this is because formula is DOCTORS ORDER/ AVAILABLE AMOUNT X D

Dr order was 30mg

available was 60 so apply formula and there si your answer

30
———————————-
60 = .5 tablets

2. Azulfidine 1.5 g has been ordered every twelve hours. The available tablets are 500 mg each. What amount will you give?

The primary role of the nurse is:
A) Utilizing technological advances to improve care
B) Assuring that all medications are given correctly
C) Assessment
D) Acting as the communication bridge between all the health care disciplines.
2. an accurate initial assessment is important because it:
A) Establishes the patient’s baseline.
B) Is the primary reference for the pharmacy
C) Shows trends in the patient’s health
D) None of the above
3. The nurse assesses a patient:
A) At the point of initial contact
B) At the conclusion of the shift
C) Whenever performing a task involving the patient
D) All of the above
4. A nurse’s “Sixth sense” refers to the feeling that:
A) It was going to be a bad day
B) Something is not right with a specific patient
C) There will be an unscheduled admission to the unit
D) The supervisor was watching
5. The primary role of the nurse within the health care team is that of:
A) The eyes and ears of the team
B) The person directly responsible for the actions of all the other team members
C) The person directly responsible for all charting
D) The person who must make all calls regarding the patient
6. Why do patients remain in the hospital?
A) Because patients and families don’t know how to provide necessary care
B) So the doctor can watch them closely
C) For nursing care and ongoing nursing assessment
D) Because all the services they need are under one roof.
7. It is good to perform the history portion of the assessment first because it:
A) helps establish rapport and sets the patient at ease
B) Establishes the base right away
C) Saves time because the patient can change into the exam gown while the nurse charts.
D) Frees up more patient examining rooms
8. Talking with a patient regarding something other than his own health, such as a friend’s recent illness—-
A) Is counterproductive because it takes the conversation off on a tangent
B) Can be beneficial because it relates to health concerns the patient has himself
C) should be avoided because it easily degrades to gossip
D) should only be done if there is no other way to get the patient to talk
9. Teaching moments can occur during the history phase of the assessment as a result of
A) questions asked by the patient
B) statements made by the patient
C) input from a family member who the patient has asked to have present
D) all of the above

10. Which of the following statements regarding medications is not true?
A) It is not uncommon, especially among older patients, for a person to be on a number of prescriptions
B) Asking about medications as a group during the history can help the patient remember them better
C) Most patients have a good understanding regarding the effects of their medications
D) It is helpful to give patients a card with all the current medications listed to carry in their wallet

11. A reproductive history should be done on all women:
A) who have children
B) who are married whether they have children or not
C) only if the reason for the assessment is gynecological in nature
D) all women of childbearing age

12. It is important to use the correct size blood pressure cuff because:
A) the wrong size can alter the reading
B) a cuff that is too small may cause bruising
C) It hurts more and patients become uncooperative
D) American Heart Association studies have shown no reasons to be concerned about cuff size

EASYSEMETER.COM BEST LINKS TO AIDE IN YOUR STUIDES

Nursing ProcessChapters: 16, 17, 18
Assessment             Chapter 16
Nursing Diagnosis        Chapter 17
Planning            Chapter 18
Assessment
Types of Data

Subjective data
Clients’ perception

Objective data
Observations / measurements of data collector
Sources of Data
Primary source: Client
Secondary Sources
Family/Significant Others
Healthcare team
Medical Records
Literature Review
Nurses experience

Methods of Data Collection
Interview

Nurse – client relationship
Mutual concern
Client’s well-being
Types of Interview Techniques
open-ended questions
back channeling
problem-seeking interview
close-ended questions
Phases of the Interview
Orientation phase

Working Phase

Termination Phase
Nursing Health History
Biographical Information
Reason for Seeking Health Care
Client Expectations
Present Illness
Past Health History
Family History
Environmental History

Nursing Health History
Psychosocial History
Spiritual Health
Review of Systems
ROS

Physical Examination
Order of Examination
Physical Examination Techniques
Inspection
palpation
percussion
Auscultation
olfactory

Nursing Diagnosis
Medical diagnosis-identification of a disease condition based on a specific evaluation of physical signs, symptoms, medical hx and dx test & procedures
Nursing diagnosis-clinical judgment about individual,family or community responses to actual or potential health problems or life processes
Nursing Diagnosis
NANDA
North American Nursing Diagnosis Association
Definition
Framework for delivering nursing care
Critical Thinking & Nursing Process
Diagnostic Process
Analysis and Interpretation of Data
Identification of Client Needs
Formulation of the Nursing Diagnosis
Nursing Diagnosis        Formulation
Actual nursing diagnosis-describes human responses to health conditions/life processes that exist in an individual, family or community.
Risk nursing diagnosis-may develop in a vulnerable individual, family or community
Wellness nursing diagnosis-human responses to levels of wellness in an individual, family or community that have a readiness for enhancement-higher level of wellness
Nursing Diagnosis Components
Diagnostic Label
Etiology
Cause
within the domain of nursing practice
condition that responds to nursing interventions
Support of Diagnostic Statement
Nursing Assessment Data
Related factors
Application to Care Planning
Advantages
Facilitate communication among nurses about client’s level of wellness & assists in discharge planning
Prioritizes client’s needs
Reference to client’s current health care needs
Used for charting in progress notes, writing referrals and transition from one unit to another
Discharge planning-used for communicating and delineating care still required
Limitations
use of nursing jargon confusing to other health care team members
May incorrectly label a client

Planning
Establish Priorities
High
Intermediate
Low
Goals of care
Role of the client in goal setting
Short term goals-short time frame
Long term goals-over weeks/months

Care Planning
Student care plans
Institutional care plan
Computerized care plan
Critical or clinical pathways
Concept Mapping
Implementing Nursing Process

Implementation-step of nursing process where nurses provide care. Initiation of actions or intervention necessary to achieve goals.

Evaluation
Final step of nursing process-determine if after applying specific interventions has the client responded and has well-being improved.
Evaluation
Evaluative Measures and sources
Quality Improvement or performance improvement
Evaluation of Care
Evaluation of Improvement

Outcomes management-managing individual outcome of clients as a result of prescribed treatments
Summary of Nursing Process
Assessment-to gather,verify & communicate data about client-to establish a data base

Nursing diagnosis-to identify health care needs of client to formulate nursing diagnosis

The nursing process is based on a nursing theory developed by Ida Jean Orlando. She developed this theory in the late 1950′s as she observed nurses in action. She saw “good” nursing and “bad” nursing. From her observations she learned:

• The patient must be the central character
   
• Nursing care needs to be directed at improving outcomes for the patient; not about nursing goals
   
• The nursing process is an essential part of the nursing care plan

Not As Complicated as it Seems
The nursing process is really not as complicated as it seems. It consists of basically five steps. Originally, Ms. Orlando had four, but through practical application over the past 40 years, one step evolved into two and now there are five. All nursing personnel take part in the nursing process. The RN has the primary responsibility however.

The Five Steps

• Assessment
• Diagnosis
• Planning
• Implementation
• Evaluation

Assessment
This is the data collection step. For RNs it also entails analyzing the data and possibly making a more complex and in-depth assessment based on the findings. LPNs, CNAs and all non-licensed nursing personnel are not trained in analyzing data. This gives rise to statements that “LPNs cannot assess patients”. In truth they do asses, they just don’t complete the second portion of that step; analysis. They may not make any independent decisions about the patient’s plan of care. It is important for LPNs as well as CNAs and non-licensed nursing personnel to understand the nursing process, but to also understand and adhere to their job description and/or scope of practice.

Assessment involves taking vital signs, performing a head to toe assessment, listening to the patient’s comments and questions about his health status, observing his reactions and interactions with others. It involves asking pertinent questions about his signs and symptoms, and listening carefully to the answers.

Once you have collected the data, the process moves on to analysis of the data to determine the health status, the patient’s coping mechanisms or lack thereof, his ability to use these mechanisms and to identify his problems related to his health status.

Diagnosis
Nurses only make nursing diagnoses, except in the case of Nurse Practitioners who have been trained and licensed to make medical diagnoses. Once you have identified the patient’s problems related to his health status, you formulate a nursing diagnosis for each of them. You will also prioritize the problems in formulating your plan and goals.

The nursing diagnoses are categorized by a system commonly referred to as NANDA. The North American Nursing Diagnosis Association (NANDA) has now become an international group who works to classify nursing diagnoses, and to review and accept new diagnoses as needed.

In 2000, NANDA adopted the current classification system (known as a taxonomy) as Taxonomy II. There are 13 domains which are subdivided into 106 classes and 155 nursing diagnoses.

The RN chooses a nursing diagnosis from the NANDA list which most closely describes the patient’s problem related to his health status. This might be a current problem or a potential problem which needs to be addressed. It can even be a problem that relates to his family rather then to him alone such as the family’s inability to cope with life style changes necessitated by the patient’s illness.

In fact, most patients will have more than one problem to diagnose and address. The severity of the problem and how it is effecting patient outcomes will determine the priority for that problem. This priority can change, and the nurse has to adapt to these changes. This is often difficult for students and new nurses to grasp. As they begin to understand and utilize the nursing process, this will become more clear.

Planning
Setting goals to improve the outcomes for the patient is a primary focus of the nursing process. Based on the nursing diagnoses, what are the expectations for this patient? This not about nursing goals. They are patient goals. This is about improving the health status and quality of life for your patient. This is about what your patient needs to do to improve his health status and/or better cope with his illness.

Planning also involves making plans to carry out the necessary interventions to achieve those goals. The use of formal care plans or care maps and protocols is highly advised.

For example: “after instruction insulin therapy, the patient will successfully return demonstrate the ability to accurately draw up the insulin by Monday and safely self inject by Tuesday.”

Implementation
Implementation is setting your plans in motion and delegating responsibilities for each step. Communication is essential to the nursing process. All members of the health care team should be informed of the patient’s status and nursing diagnosis, the goals and the plans. They are also responsible to report back to the RN all significant findings and to document their observations and interventions as well as the patient’s response and outcomes.

Evaluation
The nursing process is an ongoing process. Evaluation involves not only analyzing the success (or failure) of the current goals and interventions, but examining the need for adjustments and changes as well.  The evaluation process incorporates all input from the entire health care team, including the patient. Evaluation leads back to Assessment and the whole process begins again.

The Whole Patient
The nursing process involves looking at the whole patient at all times. It personalizes the patient. He is Mr. Jones, not “the CVA in 214B.” It also forces the health care team to observe and interact with the patient, and not just become the task they are performing such as a dressing change (the dressing change in 317A), or a bed bath. In so doing, the process provides a roadmap that ensures good nursing care and improves patient outcomes.

Most Misunderstood Theory
The nursing process is perhaps one of the most misunderstood nursing theories, and yet one of the most effective as well as practical. Many students struggle with this theory. It takes time for students and new nurses to get the hang of this process, and many fight it every step of the way, until one day a light bulb begins to burn brightly. The nursing process is used to help nurses make nursing care plans, carry them out and improve patient outcomes.

source: http://www.thenursingsite.com/nursingtheories.htm

Here are Reviews:

The Nursing Process
Elizabeth Bruderle
Villanova University

The Nursing Process

In 1980, The American Nurses’ Association (ANA) defined nursing as:

        The diagnosis and treatment of HUMAN RESPONSES to actual or potential health problems

 Introduction

     A problem-solving method
     Systematic, goal-directed, flexible, rational approach
     Ensures consistent, continuous, quality nursing care
    Provides a basis for professional accountability
     Input of nurse and patient/family critical

  The Steps of the Nursing Process are cyclic, overlapping and interrelated:

Assess
Diagnose
Evaluate
Plan
Implement

Step One of the Nursing Process:

 Assessment:  the most critical step

Answers the questions: “What is happening?” (actual problem), or 
“What could happen?” (potential problem)

    Involves collecting, organizing, and analyzing information/data about the patient

Results in  Nursing Diagnoses

    Two parts: Data collection & Data analysis

1. Data Collection: A Holistic Approach

  Types of data

     Subjective: “symptoms” that the patient describes; e.g. “I can’t do anything for myself”
     Objective: signs that can be observed, measured, and verified; e.g. swollen joints

  Sources of data

      Primary: the patient; is always the best source
      Secondary: everything/everybody else

 Methods of Data Collection

     Observation

    Requires practice and skill
    Systematic, head-to-toe (cephalocaudal)

Results in objective, factual information
Document exactly what you observe

         e.g. “Yawned frequently, had dark circles under eyes”

                  NOT “Patient seems tired”     

Observation results in a General Survey   

The General Survey: a brief description of patient’s appearance and behavior.

          64 year old, well groomed African-American male in acute distress. Awake, alert, and oriented. Approximately 6’, 170lbs. Hair sparse and gray, eyes brown. Sitting on side of bed, holding siderail for support. Verbal responses coherent but halting.       

Methods of data collection

Interview

Structured form of communicationPurpose: to provide care specific to this individual’s needs and problems
Focus: patient’s perceptions
Nurse must: explain purpose of interview, provide comfort and privacy, ensure confidentialityResult: A comprehensive Health History

Components of  the Health History

    Demographic data
    CC: chief complaint
    HPI: history of present illness
    PMH: past medical history
    FMH: family medical history (genogram)
    ROS: review of systems
    Psychosocial history

 Methods of Data Collection

     Examination

      Inspect
      Palpate
      Percuss
      Auscultate

Nurse must: explain what you are doing, provide privacy, and ask permission before you touch the patient   

2. Data Analysis

     Data review

          Are data accurate and complete?

     Data interpretation

          What are the patient’s actual and/or potential problems?
          Develop a problem list based on the data
          Prioritize the patient’s problems

Step Two of the Nursing Process  

Nursing Diagnosis:  a statement  that describes a specific human response to an actual or potential  health problem that requires nursing intervention  

       Written in P E format

          P = Problem: use North American Nursing Diagnosis Association (NANDA) category  
               [due to or related to]

          E = Etiology: cause of the problem

The Patient

 A Holistic-Physical-Emotional-Psychosocial-Developmental-Spiritual Being

                         Data Base

Medical Diagnosis        Nursing Diagnosis

Rheumatoid Arthritis Self-care deficit:bathing, related to joint stiffness                        

Step Three of the Nursing Process

    Plan: to provide consistent, contiuous care that will meet the patient’s unique needs.

     Includes Patient Goals & Nursing Orders

        Patient Goals: describe the desired result of  nursing care                       

          What will the patient (or part of the patient) do to resolve or lessen the problem identified in the         nursing diagnosis?

           By when will this be accomplished?           

Patient Goals are directly related to the patient’s problem as stated in the nursing diagnosis:

          One goal should describe resolution of the problem
         Additional goals should describe steps that contribute to problem resolution
        Patient Goals  can be long term or short term

Patient Goals are:

    Focused on the patient   
    Clear and Concise
    Observable, Measurable, Realistic: how much? how far? how long? how well?
    Written with a specific time frame: by when should the goal be accomplished?
    Determined by the nurse and the patient
    Mr. H. will perform entire bath unassisted by 4-4-01

Nursing Orders

          Describe what the nurse will do to help the patient achieve the goals.

      Nursing Orders must:

        Focus on nursing actions
        Describe when and how the nurse will perform nursing actions
       Include the date & be signed by the nurse 3/30/01 
       The nurse will assist Mr. H. with bathing qAM until he is able to bathe independently. E. Bruderle, RN 

Step Four of the Nursing Process

    Implement: Carry out the care plan

          Reassess the patient
          Validate that the care plan is accurate
          Carry out nurses’ orders
          Document on  patient’s chart

Step Five of the Nursing Process  

     Evaluate: Compare the patient’s current status with the stated Patient Goals

          Were the goals achieved? Why not?
          Review the nursing process

Problem: “I can’t do anything for myself”

Nursing Diagnosis: Self care deficit: bathing, related to joint stiffness
Patient Goal (resolution): Mr. H. will perform entire bath unassisted by 4-4-00.
Patient Goal (contributory): Mr. H. will bathe his upper body unassisted by 4-1-00.
Nursing order: 3/30/01 The nurse will assist Mr. H. with bathing q AM until he is able to bathe independently. E.Bruderle RN Evaluation: Was Mr.. H. able to bathe unassisted by 4-4-00?

Learn what forms tissues and organs and know some examples.

Your body contains one hundred million million cells and 6 billion kilometres of DNA – enough to stretch to the moon and back eight thousand times. You’re an amazing specimen – and so is the natural world.

Organisation in Living Things

Organisation in Living Things Learn what forms tissues and organs and know some examples. Organisation in Living Things View Details

2. Cell Structure and Function Learn the names and functions of some of the structures found in plant and animal cells. Cell Structure and Function View Details

3. Plant Cells Learn the names and functions of structures found in plant cells. Plant Cells View Details

4. Specialised Plant and Animal Cells Understand how different cells are adapted for their functions. Specialised Plant and Animal Cells View Details

5. Specialised Cells in the Breathing System Understand how different cells are adapted for their functions. Specialised Cells in the Breathing System View Details

6. Cell Fertilisation Learn that fertilisation in humans and flowering plants is the fusion of a male and a female cell. Cell Fertilisation View Details

7. Organ Systems Understand that different organs work together in an organ system, and learn the functions of different organ systems in the human body. Organ Systems View Details

8. Preparing Slides of Plant Cells Learn how to prepare a slide of onion cells. Preparing Slides of Plant Cells View Details

9. Preparing Slides of Animal Cells Learn how to prepare a slide of human cheek cells. Preparing Slides of Animal Cells View Details

10. Using a Microscope Learn how to use a microscope correctly. Using a Microscope View Details

Cells and Cell Functions | Humans as Organisms Green Plants as Organisms | Living Things in the Environment

11. A Balanced Diet Learn the names and sources of food types needed in a balanced diet and the different uses of food in the body. A Balanced Diet View Details

12. Malnutrition Learn about malnutrition and give some examples of diseases caused by malnutrition. Malnutrition View Details

13. Food Tests Learn how to carry out chemical tests to identify starch, sugar, protein and fat in food samples. Food Tests View Details

14. Digestion Experiments 1 Learn that enzymes digest foods so that they can be absorbed into the blood. Digestion Experiments 1 View Details

15. Digestion Experiments 2 Understand that enzymes work best at a specific pH. Digestion Experiments 2 View Details

16. Enzymes and Digestion Learn the properties of enzymes and know that some enzymes are involved in the digestion of foods. Enzymes and Digestion View Details

17. Egestion Learn that water is reabsorbed from undigested food in the large intestine before it forms waste faeces that are egested. Egestion View Details

18. The Female Reproductive System Learn the structure and function of the female reproductive organs. The Female Reproductive System View Details

19. The Male Reproductive System Learn the structure and function of the male reproductive organs. The Male Reproductive System View Details

20. Puberty Learn that changes in hormone concentrations result in the development of secondary sexual characteristics at puberty. Puberty View Details

21. The Menstrual Cycle Learn about the changes that occur in a woman’s body during the menstrual cycle. The Menstrual Cycle View Details

22. Sexual Intercourse Learn what happens during sexual intercourse. Sexual Intercourse View Details

23. Human Fertilisation Learn that fertilisation is the fusion of the egg and sperm nuclei, and know what happens to the egg after fertilisation. Human Fertilisation View Details

24. Pregnancy Understand the functions of the placenta and amniotic fluid during pregnancy. Pregnancy View Details

25. Birth Learn what happens during the birth of a baby. Birth View Details

26. Respiration Learn that aerobic respiration is a chemical reaction that occurs in cells to release energy from glucose. Learn the word equation that represents it. Respiration View Details

27. Comparing Respiration and Burning Understand the differences between aerobic respiration and burning. Comparing Respiration and Burning View Details

28. Adaptations of the Alveoli Understand how the lungs are adapted for efficient gas exchange. Adaptations of the Alveoli View Details

29. The Respiratory System Learn the structure and function of the respiratory system. The Respiratory System View Details

30. Mucous Membrane Learn how the mucous membrane lining the respiratory system helps to prevent infection. Mucous Membrane View Details

31. Gas Exchange Learn that gas exchange is the absorption of oxygen from the air into the blood and the removal of carbon dioxide from the blood. Gas Exchange View Details

32. Experiments to Compare Inhaled Air and Exhaled Air Learn how to compare inhaled and exhaled air. Experiments to Compare Inhaled Air and Exhaled Air View Details

33. Differences between Inhaled and Exhaled Air Understand the differences between inhaled and exhaled air. Differences between Inhaled and Exhaled Air View Details

34. Breathing Learn how the lungs are ventilated by breathing. Breathing View Details Breathing and Respiration View Details

35. Chemicals in Cigarette Smoke Learn some effects that the different chemicals in cigarette smoke can have on the body. Chemicals in Cigarette Smoke View Details

36. Effects of Smoking on the Lungs Learn how smoking cigarettes can damage the breathing system. Effects of Smoking on the Lungs View Details

37. The Circulatory System Learn the names of the different types of blood vessels, and that substances are exchanged between the blood and cells at capillary walls. The Circulatory System View Details Blood and Circulation View Details  The Circulatory System View Details

38. The Heart as a Double Pump Learn and understand that the heart is a double pump. The Heart as a Double Pump View Details The Heart as a Double Pump View Details

39. Temperature and Enzymes Understand how temperature affects enzyme activity. Temperature and Enzymes View Details

40. pH and Enzymes Understand how pH affects enzyme activity. pH and Enzymes View Details

41. Structure of the Heart Learn the basic structure of the heart. Structure of the Heart View Details Structure of the Heart View Details

42. Composition of the Blood Learn the components of blood and understand that many substances are transported dissolved in the plasma. Composition of the Blood View Details Composition of the Blood View Details

43. Defence Against Disease Understand how microbes can enter the body and how the body tries to prevent this from happening. Defence Against Disease View Details

44. Micro-Organisms Learn the different types of microbes that can cause disease. Micro-Organisms View Details

45. White Blood Cells Learn how the white blood cells defend the body against disease. White Blood Cells View Details

46. Blood Plasma Learn about some of the substances transported in the plasma. Blood Plasma View Details

47. Transport of Gases Learn how oxygen and carbon dioxide are transported around the body. Transport of Gases View Details

48. Vaccines Learn that immunisations and medicines can be used to help the body fight infections. Vaccines View Details

Cells and Cell Functions | Humans as Organisms Green Plants as Organisms | Living Things in the Environment

49. Photosynthesis Learn that plants make food by photosynthesis and the word equation that represents it. Photosynthesis View Details

50. The Role of the Leaf in Photosynthesis Learn that the leaf is the organ where photosynthesis occurs and understand how it is adapted for its function.   The Role of the Leaf in Photosynthesis View Details

51. Rate of Photosynthesis Learn how to measure the rate of photosynthesis and understand what factors affect it. Rate of Photosynthesis View Details

52. Testing a Leaf for Starch Learn how to test a leaf for starch. Testing a Leaf for Starch View Details

53. Experiments to see if Chlorophyll and Light are Needed to Make Starch Learn that chlorophyll and light are needed for a plant to make starch. Experiments to see if Chlorophyll and Light are Needed to Make Starch View Details

54. The Uses of Glucose Learn that the glucose made during photosynthesis can be respired or changed into a variety of chemicals by combining with other elements. The Uses of Glucose View Details

55. Plant Mineral Requirements Understand that nitrogen and other elements, in addition to carbon, oxygen and hydrogen, are required for plant growth. Plant Mineral Requirements View Details

56. Water and Mineral Salt Uptake Learn that root hair cells absorb water and mineral salts from the soil, and understand how they are adapted for this function. Water and Mineral Salt Uptake View Details

57. Differences Between Photosynthesis and Respiration Learn the differences between photosynthesis and respiration. Differences Between Photosynthesis and Respiration View Details

58. Plant Organs Learn the names and functions of some plant organs. Plant Organs View Details

Cells and Cell Functions | Humans as Organisms Green Plants as Organisms | Living Things in the Environment

59. Organ Systems at Work Understand that different organ systems work together in a healthy organism. Organ Systems at Work View Details

60. Interdependence Learn how different organisms within a community depend on each other for their survival. Interdependence View Details

61. Habitats Learn how different habitats have different features which determine the organisms that can live there. Habitats View Details

62. Studying Habitats Understand the observations and measurements that need to be made when studying a habitat. Studying Habitats View Details

63. Adaptations and Survival Learn how different organisms are adapted to survive in their habitat. Adaptations and Survival View Details

64. Seasonal Changes in Population Size Understand how some organisms are adapted to survive seasonal changes in their habitats. Seasonal Changes in Population Size View Details

65. Competition for Resources Understand that plants and animals will compete with each other if resources are limited. Competition for Resources View Details

66. Population Size Understand that the size of a population depends on the resources and space available, predators and disease. Population Size View Details

67. Sampling Technique Learn different methods of collecting animals in the wild. Sampling Technique View Details

68. Using a Quadrat Learn how to use a quadrat to estimate a plant population size. Using a Quadrat View Details