There are 10 questions worth 10 points each.
1. Runner Ron is at it again! While he was running a 100 m race (~10 sec), he consumed 1L of O2, Dr. Science only consumed 0.05 L of oxygen while watching Runner Ron win the race. Ron continued to consume O2 at a higher rate, using 4 L more than the sedentary observer (Dr. Science) over the next 5 minutes. Why do the oxygen demands remain high after Runner Ron has completed the race?
2. Dr. Science's experiment took an unexpected turn and went down a thermodynamically unexpected route. This released a whole bunch of energy in the form of a loud BOOM, thus causing a major "flight or fight" response in Dr. Science. Epinephrine went to the muscles and glucagon to the liver. Explain the effects of these two hormones on glycogen metabolism in the two tissues. Be sure to mention the end products and the advantage to having these two specific routes in addition to discussing the mechanism of the receptors and enzymes involved.
3. Type II Diabetes (NIDDM, Non Insulin Dependant Diabetes) can be treated by advising the patient to closely monitor their diet, lose weight, and to increase their exercise. This type of diabetic patient has insulin, but either has defective receptors or a lack of receptors. Discuss this in terms of the insulin receptor processing and how the prescribed treatment may work.
4. The bacteria in root nodules of legumes (peas and beans for example) consume 20% of the ATP produced by the plant. Explain why these bacteria need so much energy, and why this is a symbiotic relationship.
5. L-fluroalanine is used to inhibit the growth of bacteria that require some D amino acids as structural components of their cell membranes. What enzyme is inhibited? Discuss how the enzyme is inhibited.
6. What enzyme is the principle regulation point in fatty acid synthesis? How is this enzyme regulated? Be sure in include discussion of the specific effects of citrate and palmitoyl CoA.
7. Hypercholesteremia (too much cholesterol in the blood) is treated with the drug Mevaclor.
This drug inhibits the enzyme HMG-CoA reductase. Patients are also advised to strictly limit
their intake of saturated fats. Explain how each of these treatments reduce blood cholesterol
levels.
8. Thymidylate synthase is required to make dTMP from dUMP. The chemotherapeutic agent,
methotrexate is a structural analogue of tetrahydrofolate reductase. Discuss how
tetrahydrofolate is involved in the mechanism of thymidylate synthase. Also, why is this reaction
a good target for cancer chemotherapeutic agents?
Bonus: what is the ultimate source of the methyl group?
9. Draw the structures for the following molecules:
10. Nitric oxide was named "molecule of the year" in 1993. How is it made in the body? What effects does it have? Describe how it interacts with guanylate cyclase.