Linear Aerobic Respiration Pathway — NEET Biology
📚 Practice Concept• There is a sequential, orderly pathway functioning, with one substrate forming the next and with glycolysis, TCA cycle and ETS pathway following one after another. • The NADH synthesised in glycolysis is transferred into the mitochondria and undergoes oxidative phosphorylation. • None of the intermediates in the pathway are utilised to synthesise any other compound. • Only glucose is being respired – no other alternative substrates are entering in the pathway at any of the intermediary stages.
Which of the following statements are correct concerning the assumptions made while calculating the net gain of ATP in the respiratory balance sheet? S1. Glycolysis, TCA cycle, and ETS are considered to function in an orderly, sequential manner. S2. All NADH molecules synthesized during glycolysis are assumed to be efficiently transferred into the mitochondrial matrix. S3. Intermediates of the pathway are assumed to be readily utilized for the biosynthesis of other compounds whenever required. S4. Only glucose is considered as the primary respiratory substrate, and no other substrates enter the pathway at intermediary stages. S5. Enzymatic rates are assumed to be constantly regulated by various cellular mechanisms to maintain a steady ATP yield.
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Correct answer: B — S1, S2 and S4 only
The calculations of the respiratory balance sheet are based on specific ideal assumptions: S1. Correct. One assumption is that "There is a sequential, orderly pathway functioning, with one substrate forming the next and with glycolysis, TCA cycle and ETS pathway following one after another." S2. Correct. It is assumed that "The NADH synthesised in glycolysis is transferred into the mitochondria and undergoes oxidative phosphorylation." S3. Incorrect. The assumption is that "None of the intermediates in the pathway are utilised to synthesise any other compound," which is contrary to 'readily utilized for biosynthesis.' S4. Correct. It is assumed that "Only glucose is being respired – no other alternative substrates are entering in the pathway at any of the intermediary stages." S5. Incorrect. The theoretical calculation simplifies the system; it does not assume active regulation of enzymatic rates to maintain a steady ATP yield, but rather a fixed, ideal efficiency. Therefore, statements S1, S2, and S4 are correct assumptions. Final Answer: The final answer is B.
What does NCERT say about There sequential orderly pathway?
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Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.