Q6 / 200 · MHT CET - Medical 2026 (23 April Shift 2) · Biology
Identify the step, in which phosphorylation occurs with the help of inorganic phosphate and not ATP.
- AGlucose (6C) 1M $\rightarrow$ Glucose -6- phosphate (6C) 1M
- Correct answerBGlyceraldehyde-3-phosphate (3C) $\rightarrow$ 1,3 bisphosphoglycerate (3C)
- C2 Phosphoenol pyruvate (3C) $\rightarrow$ Pyruvic acid (3C)
- D1,3 bisphosphoglycerate (3C) $\rightarrow$ 3 Phosphoglycerate (3C)
Solution
In glycolysis, the conversion of Glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate is catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase.
During this step, oxidation of Glyceraldehyde-3-phosphate occurs, and inorganic phosphate ($H_3PO_4$ or $P_i$) is added to form 1,3-bisphosphoglycerate. ATP is not utilized in this phosphorylation step.
In the conversion of Glucose to Glucose-6-phosphate, ATP is used as the phosphate donor.
In the conversions of 1,3-bisphosphoglycerate to 3-phosphoglycerate and Phosphoenol pyruvate to Pyruvic acid, ATP is synthesized (substrate-level phosphorylation).
Answer: Glyceraldehyde-3-phosphate (3C) $\rightarrow$ 1,3 bisphosphoglycerate (3C)
During this step, oxidation of Glyceraldehyde-3-phosphate occurs, and inorganic phosphate ($H_3PO_4$ or $P_i$) is added to form 1,3-bisphosphoglycerate. ATP is not utilized in this phosphorylation step.
In the conversion of Glucose to Glucose-6-phosphate, ATP is used as the phosphate donor.
In the conversions of 1,3-bisphosphoglycerate to 3-phosphoglycerate and Phosphoenol pyruvate to Pyruvic acid, ATP is synthesized (substrate-level phosphorylation).
Answer: Glyceraldehyde-3-phosphate (3C) $\rightarrow$ 1,3 bisphosphoglycerate (3C)
Hence, the correct answer is option: 'B'.