BCHM2072/2972

1. BCHM2072/2972 2004 THEORY PAPER MCQs 41 - 54

2. 41. Graph The graph below does NOT represent: A. The rate of glucose output from the liver B. The liver glycogen content C. The activity of muscle pyruvate dehydrogenase D. The blood insulin level E. The intracellular liver concentration of fructose 2,6 bisphosphate F T T T T

3. 42. Glycogenolysis Which statement regarding the stimulation of glycogenolysis during starvation is INCORRECT? A. Phosphorylase kinase phosphorylates phosphorylase B. cAMP-dependent kinase is not activated by phosphorylation C. One phosphorylase molecule is activated for every one glucagon molecule that binds to a liver glucagon receptor D. Glucagon does not stimulate a rise in [cAMP] in muscle E. Muscle cannot convert glucose 6-phosphate into glucose for release into the blood stream T T F T T

4. 43. WAT & starvation Which statement regarding white adipose tissue after three days of starvation is CORRECT: A. Phosphodiesterase will be fully active B. Hormone sensitive lipase will be phosphorylated C. The release of fatty acids into the blood stream will be decreasing relative to day one D. The rate of glycerol release is enough to sustain the production of 120 of glucose per day E. cAMP-dependent protein kinase will be inhibited F T F F F

5. 44. Fuel stores Which of the following statements regarding our fuel stores is INCORRECT? A. In the early post-absorbtive period, the brain uses about 120g of glucose per day B. Fatty acids are released once all body glycogen stores have been used up C. Although we store most of our energy as fat, we cannot convert fatty acids into carbohydrate D. Net gluconeogenesis is possible from part of triacylglycerol E. The brain cannot use fatty acids as they do not pass across the blood-brain barrier T F T T T

6. 45. Cori cycle The Cori-Cycle to operates when: A. Liver phosphoenolpyruvate carboxykinase is activated B. Liver pyruvate carboxylase is inhibited C. Muscle beta-oxidation is inhibited D. Glucose transport into muscles is prevented E. Muscle pyruvate dehydrogenase is stimulated T F F F F

7. 46. Beta-oxidation Which statement regarding the process of beta-oxidation is CORRECT? A. The transport of fatty acids into the cell is totally dependent on a membrane carrier B. The movement of fatty acids into the mitochondrial matrix is stimulated by malonyl CoA C. The beta-oxidation of a 16-carbon fatty acyl CoA would result in the production of 8 FADH2 and 8 NADH molecules D. Matrix carnitine and cytosolic carnitine pools cannot mix E. The coupling of fatty acids to Coenzyme A involves consumption of ATP F F F F T

8. 47. Scanning check As a check on the scanning procedure enter an answer of A to question 47 on the answer sheet.

9. Use the Table below to answer Questions 48-51 Options A-E show the rates of various enzymes and pathways during exercise. The scale goes from minimum (-) to maximum (+++++). Lots of fatty acid oxidation – reasonable carb oxidation including some glycogenolysis Table Lots of glycogenolysis and next to nothing of anything else!!??. Low fatty acid oxidation but plenty of carbohydrate oxidation – all the way to CO2 Low rates of fatty acid oxidation – little carb oxidation Lots of glycogenolysis accompanied by glycolysis

10. 48. 30 minute jog Lots of fatty acid oxidation – reasonable carb oxidation including some glycogenolysis Low rates of fatty acid oxidation – little carb oxidation Which option (A-E) shows the pattern of fuel utilization after 30 minutes of jogging (moderate, aerobic exercise)?

11. 49. Sprint Which option (A-E) shows the pattern of fuel utilization during a sprint? Lots of glycogenolysis accompanied by glycolysis

12. 50. 1 hr marathon Lots of fatty acid oxidation – reasonable carb oxidation including some glycogenolysis Which option (A-E) shows the pattern of fuel utilization after 1 hour of running in a competitive long distance race (eg a marathon race)?

13. 51. Impossible Lots of glycogenolysis and next to nothing of anything else!!??. Which option (A-E) is NOT possible under any exercise scenario?

14. 52. Dietary protein What is NOT one of the fates of amino acids arising from the digestion of dietary protein? A. Deamination to produce carbon skeletons B. Conversion to glucose in the liver C. Synthesis of new protein D. Conversion to fat in the liver E. Conversion to alanine in the muscle and storage as poly-alanine Is Is Is Is No

15. 53. Protein intake For a 60 kg female, which of the follow type of protein intake would be LEAST desirable? A. 240 g/day of protein comprised of all amino acids B. 60 g/day of protein comprisedof a all amino acids C. 120 g/day of protein deficient in lysine D. 120 g/day of protein deficient in alanine E. 60 d/day of protein deficient in both alanine and glutamate OK OK NO OK OK

16. 54. Krebs cycle Which statement regarding the Krebs Cycle is CORRECT? A. Complete oxidation of one acetyl CoA in the Krebs Cycle produces 4 NADH and 1 FADH2 B. The major rate limiting steps are the reactions from succinate to oxaloacetate C. The sequence of reactions from succinate to oxaloacetate are similar to those involved in fatty acid sythesis D. The Krebs Cycle does not produce any ATP directly E. During one turn of the cycle, neither of the carbon atoms released as carbon dioxide have come from the acetyl CoA molecule that entered the cycle F F F T F