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
Substrate level phosphorylation in glycolysis is catalyzed by 
Select and explain. 
A. Glyceraldehyde 3 phosphate dehydrogenase, B. Pyruvate kinase, C. Phosphofructokinase, D. Enolase
B: Pyruvate kinase
Answer: B: Pyruvate kinase 
Explanation: In the reaction, catalyzed by phosphoglycerate kinase, phosphate is transferred from 1,3-bisphosphoglycerate onto ADP, forming ATP (substrate-level phosphorylation) and 3-phosphoglycerate. The phosphate of phosphoenolpyruvate is transferred to ADP in another substrate-level phosphorylation catalyzed by pyruvate kinase to form two molecules of ATP per molecule of glucose oxidized. Reference: Harper; 30th edition; Page no: 171