Practice multiple choice questions for VET272 EOS Exam 1. Which of the following statements regarding hexokinase is NOT CORRECT: A) The activity of hexokinase is negatively regulated via product (glucose 6 phosphate) inhibition. B) During starvation, elevated plasma glucagon leads to the phosphorylation of hexokinase in the liver, thus inhibiting its activity. C) Hexokinase has a very high affinity for glucose and other 6 carbon sugars. D) Hexokinase has a Km of 20uM. E) Compared to glucokinase, hexokinase has a much lower Vmax. 2. Gluconeogenesis utilises the majority of the enzymes in the glycolytic pathway, however the gluconeogenic obligatory quartet are essential for this pathway to proceed. Why? A) Some of the glycolytic enzymes are not expressed in the liver. B) One of the reactions in the glycolytic pathway is physiologically irreversible. C) Glycolysis does not occur in the liver. D) Three of the reactions in the glycolytic pathway are physiologically irreversible. E) Some of the glycolytic reactions proceed to slowly. 3. Choose the option below that MOST CORRECTLY completes the following statement: The role of electron shuttles is to A) Transfer glycolyticaly produced NADH into the mitochondrion for coupling with the electron transport chain to produce ATP. B) Generating reducing power (NADPH) for mitochondrial fat acid biosynthesis. C) Recycling the cytosolic pool of NADH to NAD+ thus enabling glycolysis to continue. D) Transferring the cytosolicaly produced NADPH into the mitochondrion for coupling with the electron transport chain to produce ATP. E) Options A and C above. 4. Choose the option below that MOST CORRECTLY completes the following statement: The lysosomal pathway for protein degradation is A) Stimulated by the hormone insulin. B) Stimulated by the hormone glucagon. C) Stimulated by the amino acid glycine. D) Unregulated. E) Options B and C above. 5. Choose the option below that MOST CORRECTLY completes the following statement(s): After 30 minutes of a marathon, the intensity of exercise determines the pattern of fuel utilization. Above an exercise intensity of 50% VO2Max, NEFA oxidation can no longer meet the rate of ATP demand due to a limited capacity to increase the rate of ß Oxidation. The shortfall in ATP supply is initially met by A) Increasing the aerobic catabolismof carbohydrate. B) Increasing the anaerobic catabolismof carbohydrate. C) Hydrolysis of creatine phosphate to produce ATP. D) Exercise intensity cannot exceed 50% VO2Max and so there is no shortfall in ATP supply. E) None of the above. 6. Pyruvate dehydrogenase catalyses the conversion of pyruvate to acetyl CoA. This enzyme is strongly controlled by dietary status. Why?
A) Pyruvate converted to acetyl CoA is no longer gluconeogenic. During starvation gluconeogenic carbon is preserved for glucose production to supply the glucose dependent tissues. B) When carbohydrate intake is in excess, this allows the flux of glucose carbon through to ketone body synthesis. C) When carbohydrate intake is adequate, this enables the aerobic oxidation of glucose via the TCA cycle. D) When carbohydrate intake is in excess, this allows the flux of glucose carbon through to fatty acid