1. Showing computer-generated 3-D images of macromolecules is the most effective way to convey the complexity of the large molecules of life. If this technology is not available, there are other ways to communicate the same idea.

2. The use of traditional ball and stick models can be effective. Using large items as the "balls and sticks" sometimes makes this demonstration much more meaningful for a classroom of students. Fruit, candy bars, tennis balls, hand balls, pencils, straws, or toothpicks, can represent a variety of molecules. Enlisting the help of students to "construct" these molecules is often a helpful learning mechanism and can be fun.

3. Most students are not familiar with lipids, or they are unaware of their familiarity. Displaying different types of lipids that are liquid at room temperature is a nice introduction. Several different kinds of cooking oils (safflower, olive, corn, vegetable) work well for this. Displaying lipids that are solids at room temperature, such as waxes, margarine, and lard is also a good idea. One might want to point out that the difference between whole, 2%, 1%, and skim milk is mainly the amount of lipid that each contains.

4. Shake oil and water in a sealed container.

5. Most biological membranes are lipid bilayers. Showing a computer animation of a membrane in action helps point out that the membrane has a liquid component.

1. The investment required to purchase a large, well-constructed DNA model is well worth it. DNA is probably the most widely discussed macromolecule.

2. If a large DNA model is unavailable, constructing one from everyday objects can also be instructive.

1. Showing as many images as possible of proteins and the use of proteins is a reliable way to drive home the point that proteins take many forms, participate in many, varied processes, and are a requirement for life as we know it.

2. Hormones are proteins. Showing persons displaying secondary sex characteristics (beards, breasts) is one way to point this out. Showing a picture of a person with acne is one way to demonstrate that hormones don't always cause changes that humans appreciate.

3. Hemoglobin is a protein. Show a picture of a blood bank with people donating blood.

1. Enzymes are catalysts. Show a picture of an automobile with a catalytic converter. The converter contains heavy metals like palladium and platinum that catalyze the formation of carbon dioxide from oxygen and carbon monoxide. This device reduces pollution from automobiles all over the world.

1. Showing computer-generated, 3-D images of enzymes and substrates is a good way to present this very visual, important idea.

2. A baseball glove, a tennis ball, and a handball can also be used to demonstrate simple ideas about enzymes, including various types of enzyme inhibition (e.g. competitive, noncompetitive, irreversible, and reversible).

1. The monomers of proteins are amino acids (Figure 4.4).

2. The use of computer-generated images of the chemical components of polymers and proteins aids in the understanding of the interactions between these molecules.

3. Show and discuss the structural components that all amino acids share and then show the side chains that give each a specific character (Figure 4.4). The names of the amino acids should also be discussed using a visual aid that shows the structural similarities and differences.

1. Use Figure 4.5 to illustrate electrophoresis.

2. Use clippings from newspapers and magazines that involve forensic applications for electrophoretic techniques.

3. Discuss how modern scientific advances have changed the way we solve crimes.

1. Use a rope or string with items attached to it. These items can be differently colored and shaped pieces of cardboard can be used to represent amino acids. Discuss how these chains of amino acids become proteins.

2. Use the rope of "amino acids" to discuss protein folding. Alternatively, something stiffer than rope (e.g. wiry clothesline) will help maintain shape in this case.

1. Show computer images of primary and secondary structures of proteins.

2. Figure 4.9 demonstrates how different protein structures result in different products.

3. Show pictures of or use actual animal teeth and bones to illustrate how strong collagen is. Mention skin and tendons and discuss how animal body plans would be altered if collagen didn't exist.

1. Figure 4.10 illustrates how whales can remain under water for extended periods of time due to the fact that their muscles are laden with myoglobin. Whale meat is extremely red in color due to the high concentration of myoglobin.

2. Display pieces of cooked or uncooked chicken meat. Choose the leg and thigh ("dark meat") as examples of muscles that were used by the chicken to move about. These muscles are red from myoglobin. Choose the breast ("white meat") as an example of muscles that were not used as much as the thigh or leg (because chickens in captivity don't fly). This muscle is not nearly as red as the thigh, although myoglobin is present.

1. Figure 4.13 illustrates the that fact that some denaturing processes are reversible.

2. Use a raw and a fried egg to illustrate that other denaturing processes are irreversible. It is impossible to "uncook" an egg even if the heat that cooked it is removed, or it is cooled.