1. Discuss how the different molecules such as nucleic acids and proteins can be different in various life forms but still have the same basic structure to perform the same kind of job. Why should some molecules be essentially the same in bacteria and humans and others be very different?
2. Discuss why life forms are based on carbon and note the characteristics of carbon that could be responsible for this usage. Consider why silicon, also with four electrons in its outer shell, would be good or bad as the basis of life forms.
3. List and discuss the structures and characteristics of functional groups that are important in the biochemistry of living organisms.
4. Examine the different isomeric forms of the hexose sugars glucose, fructose, and galactose, and consider the reasons for their different characteristics. Consider how the structures fit into enzymes and why different enzymes would be needed to interact with different isomers.
5. Consider whether condensation and hydrolysis reactions would be exact opposites of each other. Point out that these reactions are not generally one-step processes but require several steps and several enzymes to carry out the complete reaction.
6. Consider what would happen if genetic engineering allowed us to incorporate into human cells the ability to digest cellulose. Would that be useful or not? Think about the structure of our digestive tracts and the current use of cellulose as roughage.
7. Discuss how denaturation affects the different levels of a protein's structure and which levels would be most affected by it. Contrast the denaturation caused by heat (cooking food) as opposed to mild denaturation caused by reversible pH changes.
8. Compare the different types of subunits and bonds
that link the carbohydrates, lipids, proteins, and nucleic acids.
Consider the size of the final molecules and which ones are branched
and unbranched. Prepare the students for the link between the
information in DNA and RNA and that in proteins that will be discussed
later.