Respiration in Plants MCQs

Consider the sequence of steps in Glycolysis:

I. Fructose-6-phosphate → Fructose-1,6-bisphosphate.
II. 3-PGAL → 1,3-bisphosphoglycerate (BPGA).
III. 3-phosphoglycerate → 2-phosphoglycerate.
IV. Phosphoenolpyruvate → Pyruvic acid.

Which of the above sequence order is correct as glycolysis progresses?

Regarding net yield starting from ONE molecule of SUCROSE in glycolysis:

I. One sucrose yields 2 molecules of hexose sugars (glucose + fructose).
II. Gross ATP synthesis from one sucrose = 8 ATP.
III. Net ATP gain directly via substrate-level phosphorylation = 4 ATP.
IV. Total NADH + H⁺ formed = 4 molecules.

Which of the above statements are correct?

Which of the following statements about NAD⁺ during glycolysis is correct?

I. NAD⁺ gets reduced to NADH + H⁺ by accepting hydrogen atoms from PGAL.
II. NAD⁺ pool must be continuously reoxidized for glycolysis to continue.
III. In anaerobic conditions, fermentation reoxidizes NADH back to NAD⁺.
IV. In aerobic conditions, NADH is reoxidized via mitochondrial ETS.

Select the correct option.

Statement analysis on Triose Phosphate Intermediates:

I. Glyceraldehyde-3-phosphate (PGAL) is an aldose triose phosphate.
II. Dihydroxyacetone phosphate (DHAP) is a ketose triose phosphate.
III. Both PGAL and DHAP contain 3 carbon atoms and 1 phosphate group.
IV. DHAP is oxidized directly to BPGA without isomerization.

Which statements are correct?

Consider the following statements about the EMP pathway overall efficiency:

I. Less than 7% of total energy in glucose is trapped during anaerobic glycolysis.
II. Most energy of glucose remains locked inside two pyruvic acid molecules.
III. Glycolysis yields complete carbon oxidation into CO₂.
IV. Net energy extracted in glycolysis is sufficient for high energy demands of complex animals.

Which statements are correct?

Consider the following statements regarding Alcoholic Fermentation:

I. Pyruvic acid is converted into ethanol and CO₂.
II. Enzymes involved are pyruvic acid decarboxylase and alcohol dehydrogenase.
III. NADH + H⁺ acts as reducing agent and gets reoxidized to NAD⁺.
IV. It occurs naturally in muscle cells during strenuous physical exercise.

Which of the statements given above are correct?

Read the following statements about Lactic Acid Fermentation:

I. Pyruvic acid is reduced directly to lactic acid by lactate dehydrogenase.
II. Carbon dioxide (CO₂) gas is liberated during this reaction.
III. The reducing agent is NADH + H⁺.
IV. It occurs in some bacteria and oxygen-deprived animal muscle cells.

Which of the above statements are incorrect?

Consider the following statements about Yeast poisoning during fermentation:

I. Yeast cells poison themselves to death when alcohol concentration reaches about 13 percent.
II. Maximum alcohol concentration in naturally fermented beverages does not exceed approximately 13%.
III. Alcoholic beverages with more than 13% alcohol content are produced by distillation.
IV. Yeast can survive indefinitely in 50% ethanol solutions.

Which of the above statements are correct?

Regarding energy release during Fermentation:

I. Less than seven per cent of the energy in glucose is released during fermentation.
II. All released energy is completely trapped as high-energy bonds of ATP.
III. Net gain of ATP per glucose molecule in fermentation is only two ATP.
IV. Fermentation yields more ATP per glucose than aerobic respiration.

Which of the above statements are correct?

Compare NADH oxidation rate in Fermentation vs Aerobic Respiration:

I. NADH is reoxidized to NAD⁺ rather slowly in fermentation.
II. NADH oxidation is very vigorous in aerobic respiration via ETS.
III. Fermentation requires O₂ for NADH oxidation.
IV. Slow NADH oxidation in fermentation limits the rate of glycolysis.

Which statements are correct?