This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Carbohydrates, Subject name: Biochemistry
The rate limiting enzyme in glycolysis is 
Select and explain. 
A. Glucose 6- dehydrogenase, B. Phosphofructokinase, C. Glucokinase, D. Pyruvate kinase
B: Phosphofructokinase
Answer: B: Phosphofructokinase 
Explanation: (Phosphofroctokinase) (152- Harper 27th) (108- Lippincott's)Phosphofroctokinase - is the pace- setting (rate- limiting) enzyme of glycolysis. It is inhibited by ATP and citrate uses fructose 6- phosphate as substrate, and catalyzes a reaction that is for from equilibrium. The reaction is activated by fructose 2- 6 biphosphate