General
✓✗The number of CO2 molecules released when two molecules of pyruvic acid are converted into acetyl CoA is
- 1
- 2
- 4
- 6
General
✓✗The difference between oxidative phosphorylation and photophosphorylation is mainly in the
- final product that is formed
- enzyme used to make the ATP
- need for a membrane system
- energy source of the proton gradient
General
✓✗Assertion (A): The RQ of fats is less than that of carbohydrates.
Reason (R): Fats contain relatively less oxygen and need more O2 for complete oxidation.
Reason (R): Fats contain relatively less oxygen and need more O2 for complete oxidation.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true but R is false.
- Both A and R are false.
General
✓✗Which statement correctly explains why fermentation cannot meet the energy needs of large active animals?
- It needs light and works only during the day.
- It uses far too much O2 for active animals.
- It needs mitochondria, which muscles lack.
- It gives only 2 ATP per glucose and toxic products.
General
✓✗In alcoholic fermentation, acetaldehyde is
- oxidised to acetic acid
- converted to lactic acid
- reduced to ethanol by NADH
- phosphorylated to give ATP
General
✓✗When one glucose molecule is completely oxidised, it changes
- 30 ADP molecules into 30 ATP molecules
- 38 ADP molecules into 38 ATP molecules
- 36 ADP molecules into 36 ATP molecules
- 32 ADP molecules into 32 ATP molecules
General
✓✗The RQ of a pure protein substrate is about 0.9, but measured RQ values in living organisms rarely equal exactly 0.7, 0.9 or 1.0 because
- CO2 is never released by the cells
- several substrates are respired together
- O2 is never used by living cells
- RQ does not depend on the substrate
General
✓✗Assertion (A): In the electron transport system, electrons move downhill in terms of energy.
Reason (R): Electrons pass from carriers with lower redox potential to carriers with higher redox potential, releasing energy.
Reason (R): Electrons pass from carriers with lower redox potential to carriers with higher redox potential, releasing energy.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true but R is false.
- Both A and R are false.
General
✓✗Which of the following statements about glycolysis is INCORRECT?
- It produces a net gain of 2 ATP per glucose.
- It requires molecular oxygen.
- It produces 2 NADH per glucose.
- It occurs in the cytoplasm.
General
✓✗The two main events of aerobic respiration, after glycolysis, are
- transpiration through stomata and guttation through hydathodes
- fermentation of pyruvate and glycolysis of glucose in the cytoplasm
- oxidation of pyruvate in the TCA cycle, and the ETS with ATP synthesis
- photolysis of water and fixation of carbon dioxide in the stroma
General
✓✗The first product of the TCA cycle is
- citric acid
- oxalosuccinic acid
- oxaloacetic acid
- cis-aconitic acid
General
✓✗Glycolysis is also known as the
- EMP pathway
- HMP pathway
- Krebs cycle
- Calvin cycle
General
✓✗If acetyl CoA labelled with 14C in its acetyl group enters the TCA cycle, in the first turn the labelled carbons will be found in
- citric acid
- CO2 released in the link reaction
- pyruvic acid
- glucose
General
✓✗Why is the RQ of an animal on a mixed diet usually between 0.7 and 1?
- Carbohydrates and fats are respired together.
- Only fats are respired in all its cells.
- Respiration is anaerobic in all its cells.
- Only glucose is respired in all its cells.
General
✓✗In animal muscle cells during vigorous exercise, pyruvic acid is reduced to
- ethanol
- lactic acid
- citric acid
- acetyl CoA