Questions 1 thru 13 are worth 3 points each, question 14 is 5 points, and question 15 is worth 6 points.

1. What are coenzymes, and what are their functions?
2. List three criteria which must be met for an enzyme to be active.
3. How are enzymes classified? Give an example of this naming system not readily found in Chapter 6 of your text.
4. In qualitative terms, explain the relationship between the activation energy for an enzymatic reaction and the rate constant k.
5. There are 4 physical and thermodynamic barriers to a reaction. Name 3 and briefly explain how they are overcome through enzymatic catalysis.
6. How do metal ions participate in catalysis?
7. Explain how pH affects enzyme activity.
8. List the functional groups that can be added to an enzyme to enhance or attenuate its activity.
9. Why is the control of catalysis important in biological systems?
10. How do allosteric enzymes differ from other enzymes?
11. What type of enzymes are NOT proteins?
12. State what type of reaction is catalyzed by protein kinases, and briefly state why it would be beneficial for this to generally be reversible.
13. The rate-limiting enzyme in the synthesis of dopamine is tyrosine hydroxylase (TH). Chronic treatment with a dopamine agonist, such as methamphetamine, can decrease the expression of TH. The regulatory enzyme is inhibited by the end product of its pathway. This type of regulation is known as ______ ________.
14. Metabolism of many agents can be described using the Michaelis-Menten equation to yield a straight-line double-reciprocal plot. Some enzymes, however, exhibit atypical kinetics due to substrate activation or substrate inhibition. Search the internet for an example of the above. List the enzyme you find and the type of curve you would expect to describe it. Provide a journal article citation for the information you provide.
15. Locate the following article and answer the questions that follow:

Samuel M, Lu M, Pachuk C, and Satishchandran C. (2003) Analytical Biochemistry, 313 (2): 301-306.
a) The authors wished to quantify linear DNA. What did they actually measure?
b) Enzymatic activity was demonstrated as being linear with enzyme concentration until about 60% of the substrates were converted to products. What is a probable explanation given for this behavior?
c) Do the data presented in figures 4 and 5 support the use of the enzyme as a means of quantifying linear DNA content?

Questions 1 thru 10 are worth 4 points each, questions 11 and 12 are each worth 5 points.

1. Why are monosaccharides insoluble in non-polar solvents?
2. How does the word chiral relate to carbohydrate structure?
3. What is the structural difference between mannose and galactose?
4. What are the structural and functional difference between homo- and heteropolysaccharides?
5. Name two structural homopolysaccharides.
6. Explain the difference between a proteoglycan and a glycoprotein.
7. What are the functional differences between glycoproteins and glycosaminoglycans?
8. What are the structural differences between glycogen and cellulose; how do these affect their function, and why can’t cellulose be used by most organisms to generate energy?
9. Discuss in detail the factors that influence the folding of homopolysaccharides.
10. Why are enzymes a powerful tool in the preliminary stages of carbohydrate analysis?

1. Searching the literature, provide a named example whereby a membrane-bound carbohydrate or glycoprotein serves as a signaling molecule. Discuss and provide your reference for the journal article.

1. Searching the internet, find two different examples of methods for the analysis of oligosaccharides and discuss your findings, as well as provide your reference
4. Questions 1 thru 15 are worth 3 points each, and 16 is worth 5 points.
5. 1. Explain why fats and oils are insoluble in water.
   2. Explain the significance of lysosomes, as they relate to sphingo – and phospholipids.
   3. Compare and contrast how sterols resemble and differ from other membrane lipids.
   4. What about the structure of isoprene makes isoprenoids biologically important?
   5. How are specific enzymes used in the structural analysis of lipids?
   6. What is the primary intracellular function of phosphatidylinositols?
   7. Define the term amphipathic. Provide one example of an amphipathic small molecule and one, which is a macromolecule.
   8. How do the chemical properties of storage lipids and membranes differ, and how does this relate to their functions?
   9. What effect does analysis by gas-liquid chromatography have on the biological activity of lipids?
   10. Searching the Internet, locate and briefly discuss two techniques that may be used in the chiral analysis of lipids.
   11. How, other than in synthesis, do the eicosanoids differ from steroid hormones?
   12. What are the advantages of using triacylglycerols versus polysaccharides in both plants and animals as fuel storage?
   13. Briefly discuss the relationship between fatty acid melting point and degree of saturation.
   14. Glycosphingolipids may function as antigens, mediators of cell adhesion, and modulators of signal transduction. They are amphipathic compounds.
       True or False
   15. Lipofuscin is an important lipid or fatty-pigment.

       Read the article listed here and answer the questions that follow:
       Brunk UT and Terman A. (2002) Free Radical Biology and Medicine, 33 (5): 611-619.

       a).Why is lipofuscin associated with aging?
       b).Why do only postmitotic or slowly dividing cells accumulate lipofuscin versus actively proliferating cells?

   16. The process of cholesterol biosynthesis has five major steps:
       1. Acetyl-CoAs are converted to HMG-CoA {HMG CoA synthase}
       2. HMG-CoA is converted to mevalonate {HMG CoA reductase}
       3. Mevalonate is converted to the isoprene based molecule IPP
       4. IPP is converted to squalene {Squalene synthase}
       5. Squalene is converted to cholesterol {Squalene monooxygenase}

   Statin are pharmaceuticals, which have become widely accepted as cholesterol lowering medications that act by competitively inhibiting HMG CoA reductase.

   Read the article referenced below and answer the question which follows:

   Chugh A, Ray A, and Gupta JB. (2003) Progress in Lipid Research, 42 (1): 37-50.
   a).Drugs are being developed to target squalene monooxygenase (aka squalene epoxidase). What would be the benefit of targeting the later step with the proposed drugs as opposed to the statins?