This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Biochemistry
The glycolysis is regulated by 
Select and explain. 
A. Hexokinase, B. Phosphofructokinase, C. Pyruvate kinase, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Regulation of glycolysis The three enzymes namely hexokinase (and glucokinase), phosphofructokinase and pyruvate kinase, catalysing the irreversible reactions regulate glycolysis. Hexokinase is inhibited by glucose 6-phosphate. This enzyme prevents the. accumulation of glucose 6-phosphate due to product inhibition. Glucokinase, which specifically phosphorylates glucose, is an inducible enzyme. The substrate glucose, probably through the involvement of insulin, induces glucokinase. Phosphofruclokinase (PFK) is the most Impoant regulatory enzyme in glycolysis. This enzyme catalyses the rafe limiting committed step. PFK is an allosteric enzyme regulated by allosteric effectors. ATP, citrate and H+ ions (low pH) are the most impoant allosteric inhibitors, whereas, fructose 2,6-bisphosphate, ADP, AMP and Pi are the allosteric activators Ref : Biochemistry by U. Satyanarayana 3rd edition Pgno : 250