This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
Inorganic phosphate is used in which enzyme of glycolysis? 
Select and explain. 
A. Glucose-6-phosphatase, B. Phospho fructokinase, C. Phosphoglycerate kinase, D. Enolase
C: Phosphoglycerate kinase
Answer: C: Phosphoglycerate kinase 
Explanation: Step 6 of Glycolysis- i. The energy of 1,3-BPG is trapped to synthesize one ATP molecule with the help of bisphospho-glycerate kinase. ii. This is an example of substrate level phosphorylation, where energy is trapped directly from the substrate, without the help of the complicated electron transpo chain reactions. iii. When energy is trapped by oxidation of reducing equivalents such as NADH, it is called oxidative phosphorylation. Step 6 is reversible. Ref: DM VASUDEVAN TEXTBOOK OF BIOCHEMISTRY,EIGHTH EDITION,PG.NO.,130.