NEET2026BiologyChapterActual
Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In the energy-extracting phase of glycolysis, there is a direct synthesis of ATP at two distinct steps. Reason (R): Substrate-level phosphorylation occurs when 1,3-bisphosphoglyceric acid (BPGA) is converted to 3-phosphoglyceric acid (PGA) and when phosphoenolpyruvate (PEP) is converted to pyruvic
Options
- AAssertion (A) is true but Reason (R) is false.
- BAssertion (A) is false but Reason (R) is true.
- CBoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- DBoth Assertion (A) and Reason (R) are true but Reason (R) is NOT the correct explanation of Assertion (A).
Correct answer
C. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true because during the energy-extracting (pay-off) phase of glycolysis, ATP is directly synthesized at two distinct steps. Reason (R) is true and correctly explains Assertion (A) by specifying these two steps. The direct synthesis of ATP from metabolites is called substrate-level phosphorylation. In glycolysis, this occurs first when 1,3-bisphosphoglyceric acid (BPGA) is converted into 3-phosphoglyceric acid (PGA) by phosphoglycerate kinase, and second when phosphoenolpyruvate (PEP) is converted i