Respiration in Plants MCQs

Consider the end products of anaerobic pathways:

I. Yeast fermentation yields Ethanol + CO₂.
II. Lactic acid bacteria fermentation yields Lactic acid.
III. Anaerobic muscles yield Lactic acid + CO₂.
IV. Germinating seeds under anaerobic conditions can undergo alcoholic fermentation.

Which statements are correct?

Regarding hazardous nature of fermentation products:

I. Accumulation of acid lowers cellular pH, disrupting enzymes.
II. High ethanol levels dissolve cell membranes and cause cell death.
III. Fermentation products are harmless metabolic nutrients for host cells.
IV. Yeasts die when ethanol reaches toxic levels (approximately 13%).

Which statements are correct?

Net ATP calculations for Fermentation starting from one molecule of Glucose:

I. Gross ATP synthesized in glycolysis = 4 ATP.
II. ATP utilized in glycolysis = 2 ATP.
III. Additional ATP synthesized during pyruvate reduction to alcohol/lactate = 2 ATP.
IV. Net ATP yield = 2 ATP.

Which statement is INCORRECT?

Read the following statements regarding Pyruvic acid decarboxylase:

I. Catalyzes conversion of Pyruvic acid to Acetaldehyde and CO₂.
II. Functions during lactic acid fermentation.
III. Requires TPP and Mg²⁺ as cofactors.
IV. Involved in alcoholic fermentation in yeast.

Which statements are correct?

Statement analysis on redox reactions in fermentation:

I. Pyruvic acid undergoes reduction in both lactic and alcoholic fermentation.
II. NADH + H⁺ acts as reducing agent and gets oxidized to NAD⁺.
III. Molecular oxygen acts as final electron acceptor in fermentation.
IV. Organic intermediates act as electron acceptors in fermentation.

Which statements are correct?

Consider the conditions under which skeletal muscle cells produce Lactic Acid:

I. During heavy physical exercise when O₂ supply is inadequate.
II. When rate of glycolysis exceeds capacity of aerobic respiration.
III. To regenerate NAD⁺ required to keep glycolysis operating.
IV. When O₂ concentration inside mitochondria is extremely high.

Which statements are correct?

Regarding beverages produced by distillation vs natural fermentation:

I. Wine and beer are produced by natural fermentation without distillation.
II. Whisky, brandy, and rum are distilled alcoholic beverages.
III. Distillation increases alcohol concentration above 13%.
IV. Natural fermentation can produce beverages with 95% alcohol content without yeast death.

Which statements are correct?

Which of the following equations correctly represents Alcoholic Fermentation?

I. Pyruvic acid → Ethanol + CO₂ (via decarboxylase and dehydrogenase).
II. Pyruvic acid + NADH + H⁺ → Lactic acid + NAD⁺ (via lactate dehydrogenase).
III. Glucose → 2 Lactic acid + 2 ATP.
IV. Pyruvic acid + CoA + NAD⁺ → Acetyl CoA + CO₂ + NADH + H⁺.

Select the option representing alcoholic fermentation.

Statement analysis regarding overall energy recovery in fermentation:

I. Glucose is incompletely degraded into small organic molecules.
II. Majority of energy remains locked in end-products like ethanol or lactic acid.
III. Efficiency of energy trapping in fermentation is less than 7%.
IV. Fermentation produces 38 ATP per glucose.

Which statements are correct?

Consider the following statements comparing lactic acid bacteria and yeast:

I. Both can extract energy under anaerobic conditions.
II. Both produce CO₂ gas as a byproduct.
III. Both regenerate NAD⁺ from NADH.
IV. Lactic acid bacteria form lactic acid while yeasts produce ethanol + CO₂.

Which statements are correct?