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10.1 Integration of Metabolism β Test 1
Q1. Statement (S): Cancer cells often decouple glycolysis from the TCA cycle. Reason (R): The Warburg effect is beneficial to cancer cells. Which is correct?β Both S and R correct, R is the right explanation of S
Q2. The hormones epinephrine and glucagon regulate metabolism by:β Activating gluconeogenesis and inhibiting glycolysis
Q3. Elevated circulating glucagon is associated with which one of the following?β Increased activity of phosphofructokinase-2
Q4. Which one of the following statements is correct?β Glycogen hydrolysis is promoted by glucagon
Q5. Which statement about insulin action is correct?β Insulin signalling opposes glycogenolysis
Q6. Which compound is shared by the TCA cycle and the urea cycle?β Fumarate
Q7. The common intermediate of protein, carbohydrate and lipid metabolism is:β Acetyl-CoA
Q8. The common intermediate of carbohydrate, protein and lipid metabolism is (variant):β Acetyl-CoA
Q9. Complete aerobic respiration of glucose produces:β Water and carbon dioxide
Q10. Oxidation of fats and carbohydrates within cells is an example of:β Catabolism
Q11. Which set of features is indicative of a CATABOLIC pathway? a) consumption of ATP; b) reduction using NADPH; c) yielding energy; d) involvement of NADβΊ; e) glucose production by photoautotrophs; f) decrease in molecular complexityβ c, d, f
Q12. Why can animals not achieve net reduction of COβ even though COβ is fixed at steps like acetyl-CoAβmalonyl-CoA, pyruvate carboxylase, and carbamoyl phosphate synthesis? Reasons: 1) COβ is lost in later steps of these pathways; 2) availability of COβ is limited; 3) animals lack a distinct metabolic route for net COβ use.β Only 1 and 3
Q13. In aerobic organisms glycolysis is followed by the citric acid cycle. Match the enzyme/reaction with its subcellular location:β i-2, ii-1, iii-3, iv-2
Q14. Animals cannot synthesise ethanol in their bodies because they lack which enzyme?β Pyruvate decarboxylase
Q15. Glucose is oxidised (glycolysis) in which part of the cell?β Cytoplasm
Q16. Match the high-energy compound with the biosynthetic pathway it powers:β i-3, ii-4, iii-2, iv-1
10.1 Integration of Metabolism β Test 2
Q17. Match the high-energy compound with the biosynthetic pathway it powers (variant):β i-3, ii-4, iii-2, iv-1
Q18. In coordinated metabolism, malate crosses the mitochondrial membrane and forms cytosolic oxaloacetate, which can be transaminated to:β Aspartate
Q19. Match the pentose phosphate / glycolytic intermediate with the enzyme acting on it:β i-c, ii-d, iii-b, iv-a
Q20. Which pair of enzyme complexes performs mechanistically similar functions?β Pyruvate dehydrogenase and Ξ±-ketoglutarate dehydrogenase
Q21. In glucose oxidation (CβHββOβ + 6Oβ β 6COβ + 6HβO), the oxygen atoms of the water formed come:β Entirely from respiratory oxygen
Q22. Match the pathway with the cell compartment where it occurs:β i-4, ii-3, iii-2, iv-1
Q23. According to Randle's (glucoseβfatty acid) cycle, how do free fatty acids compete with glucose metabolism?β FFA oxidation raises acetyl-CoA/citrate, inhibiting PDH and PFK so glucose use falls
Q24. Opposing reactions in glucose metabolism (e.g. PFK vs fructose-1,6-bisphosphatase running together) constitute a:β Substrate (futile) cycle
Q25. A futile (substrate) cycle:β All of the above
Q26. The conversion of sucrose (CββHββOββ) ultimately to COβ in respiration is an example of:β Oxidation
Q27. Which tissue CANNOT use fatty acids as a source of energy?β Neural tissue (brain)
Q28. Which compound is shared by the TCA cycle and the urea cycle?β Fumarate
Q29. Which mechanism helps maintain ATP levels in vigorously contracting muscle (fastest immediate source)?β Creatine phosphate donates phosphate to ADP to replenish ATP
Q30. Which mechanism helps maintain ATP in rigorously contracting muscle (variant)?β Creatine phosphate donates phosphate to ADP
Q31. During prolonged starvation, the brain adapts by deriving much of its energy from:β Ketone bodies