Biochemistry Past Paper PDF

**Q1: In summary, the TCA cycle plays with carbon atoms by carrying out one of the schemes shown below:** - **Answer: D) Adds 4 carbons to 2 carbons and takes away 2 carbons.** **Q2: The central reason for the cell having to effect the TCA cycle is?** - **Answer: D) to produce reduced coenzymes as...

**Q1: In summary, the TCA cycle plays with carbon atoms by carrying out one of the schemes shown below:** - **Answer: D) Adds 4 carbons to 2 carbons and takes away 2 carbons.** **Q2: The central reason for the cell having to effect the TCA cycle is?** - **Answer: D) to produce reduced coenzymes as electron carriers.** **Q3: The phenomenon of proton motif force (PMF) is core to the success of the?** - **Answer: D) Chemiosmosis hypothesis for ATP generation in the cell.** **Q4: Carbon monoxide is biochemically toxic to mammalian cells because?** - **Answer: B) It inhibits complex IV (cytochrome oxidase) which normally donates electrons to oxygen for the formation of water.** **Q5: In glycolysis, pyruvate is converted to lactate or lactic acid under one of these physiological conditions:** - **Answer: B) Complete anaerobiosis.** **Q6: How many times will the TCA cycle turn to completely metabolize the pyruvic acid produced from one glucose molecule?** - **Answer: B) 2** **Q7: During glycolysis which one of the following statements is actually correct?** - **Answer: A) A molecule of glucose is converted into two molecules of pyruvic acid.** **Q8: Inside of the mitochondrion, each pyruvic acid molecule** - **Answer: A) forms a molecule of citric acid.** **Q9: For the TCA cycle, one of the following statements is most appropriate:** - **Answer: A) begins with the formation of a molecule of citric acid.** **Q10: The carbon dioxide of respiration is formed during** - **Answer: B) The TCA cycle.** **Q11: In the electron transport chain** - **Answer: D) All of the above** **Q12: The process by which ATP is synthesized across the inner mitochondria membrane is achieved by?** - **Answer: C) Chemiosmosis.** **Q13: In glycolysis, how many molecules of ATP are formed from each molecule of glucose that is catabolized?** - **Answer: B) 4** **Q14: Biotin is necessary for the efficient transfer of:** - **Answer: A) Acetyl group** **Q15: A cation that acts as a cofactor for enzymes that are required for normal glycolysis is:** - **Answer: B) potassium.** **Q16: The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin** - **Answer: A) A.** **Q17: Amino acid catabolism normally supplies about:** - **Answer: E) 20% of human energy needs** **Q18: High concentrations of reduced glutathione is essential for achieving all of the following except?** - **Answer: D) causing red blood cell haemolysis** **Q19: Pyridoxal phosphate is truly related to all the following except?** - **Answer: B) Is a fat soluble vitamin.** **Q20: Phosphofructokinase-1 activity is enhanced by increased concentrations of:** - **Answer: B) ADP**