Statement analysis on Proton Gradient generation across the inner mitochondrial membrane:
I. Protons (H+) are pumped from the matrix into the intermembrane space as electrons flow through ETS. II. Higher H+ concentration builds up in the intermembrane space relative to the matrix. III. The proton gradient drives H+ back into the matrix through the F0 channel of ATP synthase. IV. Protons flow from the matrix to the intermembrane space through the F1 particle to generate ATP.
Which statements are correct?
Statement IV is incorrect because protons move from the intermembrane space to the matrix through the F0 channel, driving ATP synthesis at the F1 headpiece. Statements I, II and III are correct.
Question 82 of 100
📘 CLASS XI
Sequence of electron flow in ETS from NADH to Oxygen:
I. Complex I → Ubiquinone → Complex III → Cytochrome c → Complex IV → O2. II. Complex II → Ubiquinone → Complex III → Cytochrome c → Complex IV → O2. III. Complex I → Complex II → Complex III → Complex IV. IV. Complex IV → Cytochrome c → Complex III → Ubiquinone → O2.
Which option lists the correct path for NADH oxidation?
Path I represents the exact electron flow for NADH oxidation: Complex I → Ubiquinone → Complex III → Cytochrome c → Complex IV → Oxygen.
Question 83 of 100
📘 CLASS XI
Regarding Mobile Electron Carriers in the inner mitochondrial membrane:
I. Ubiquinone is a mobile carrier within the lipid bilayer. II. Cytochrome c is a mobile carrier attached to the outer surface of the inner mitochondrial membrane. III. Complex I and Complex IV are mobile electron carriers floating in the matrix. IV. Mobile carriers transfer electrons between stationary protein complexes.
Which statements are correct?
Statement III is incorrect because Complexes I, II, III and IV are fixed transmembrane protein complexes embedded in the inner mitochondrial membrane. Statements I, II and IV are correct.
Question 84 of 100
📘 CLASS XI
Statement analysis on Chemiosmotic Hypothesis in Mitochondria:
I. Proposed by Peter Mitchell. II. Requires intact inner mitochondrial membrane, proton pump, proton gradient, and ATP synthase. III. Breakdown of proton gradient releases energy for ATP synthesis. IV. Matrix pH becomes lower (more acidic) than intermembrane space during ETS activity.
Which statements are correct?
Statement IV is incorrect because H+ accumulates in the intermembrane space, making it more acidic while the matrix remains relatively alkaline. Statements I, II and III are correct.
Question 85 of 100
📘 CLASS XI
Total ATP yield from complete oxidation of one molecule of cytosolic NADH via glycerol-phosphate vs malate-aspartate shuttle:
I. Cytosolic NADH from glycolysis must be transported into mitochondria. II. It yields 2 or 3 ATP per NADH depending on the shuttle mechanism used. III. Cytosolic NADH produces 10 ATP directly without entering ETS. IV. Transport of cytosolic NADH may alter net ATP yield due to shuttle mechanism.
Which statements are correct?
Statement III is incorrect because cytosolic NADH must transfer its reducing equivalents into mitochondria and generate ATP through the electron transport system. Statements I, II and IV are correct.
Question 86 of 100
📘 CLASS XI
Consider the assumptions made while calculating the theoretical net gain of 38 ATP per glucose:
I. Sequential orderly functioning of Glycolysis → TCA cycle → ETS. II. Glycolytic NADH is transferred into mitochondria and undergoes oxidative phosphorylation. III. Intermediates are not withdrawn for synthesis of other compounds. IV. Only glucose is respired without entry of alternative substrates.
Which statements are correct?
All four assumptions are explicitly considered while calculating the theoretical yield of 38 ATP per glucose molecule.
Question 87 of 100
📘 CLASS XI
Why are assumptions of the respiratory balance sheet not strictly valid in living systems?
I. Metabolic pathways operate simultaneously rather than sequentially. II. Intermediates are withdrawn or added according to cellular needs. III. ATP is utilized immediately as required by the cell. IV. Enzyme activities are dynamically regulated by feedback mechanisms.
Which statements are correct?
All four statements correctly explain why the theoretical respiratory balance sheet differs from actual ATP production in living cells.
Question 88 of 100
📘 CLASS XI
Breakdown of the theoretical 38 ATP yield from one glucose molecule:
I. Glycolysis: Direct 2 ATP + 2 NADH (6 ATP). II. Link Reaction: 2 NADH (6 ATP). III. TCA Cycle: 2 GTP (2 ATP) + 6 NADH (18 ATP) + 2 FADH2 (4 ATP). IV. Total theoretical yield = 38 ATP.
Which statements are correct?
All four statements correctly represent the classical theoretical ATP balance sheet yielding 38 ATP per glucose molecule.
Question 89 of 100
📘 CLASS XI
Compare net ATP yield: Fermentation vs Aerobic Respiration.
I. Fermentation yields a net gain of 2 ATP per glucose. II. Aerobic respiration yields up to 38 ATP per glucose. III. Aerobic respiration is about 19 times more efficient in ATP production than fermentation. IV. Fermentation yields more ATP than aerobic respiration.
Which statements are correct?
Statement IV is incorrect because aerobic respiration yields far more ATP than fermentation. Statements I, II and III are correct.
Question 90 of 100
📘 CLASS XI
Statement analysis on energy efficiency of Aerobic Respiration:
I. Approximately 40-45% of glucose energy is trapped in ATP. II. Remaining energy is released mainly as heat. III. Aerobic respiration traps less energy than anaerobic fermentation. IV. Stepwise oxidation allows efficient coupling of energy to ATP synthesis.
Which statements are correct?
Statement III is incorrect because aerobic respiration traps much more energy than fermentation. Statements I, II and IV are correct.
