This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
In glycolysis the first commited step is catalysed by: 
Select and explain. 
A. 2,3 DPG, B. Glucokinase, C. Hexokinase, D. PFK
D: PFK
Answer: D: PFK 
Explanation: Fructose 6 Phosphate is phosphorylated to Fructose 1, 6 Bisphosphate by Phosphofructokinase I (PFK-I)
Second irreversible step
Major regulatory step of Glycolysis
Committed step of GIycolysis because once Fructose
1, 6 Bisphosphate is formed it should undergo glycolysis
Otherwise called bottle neck of Glycolysis
1 ATP is utilized.

Key Concept:

First Committed step is catalyzed by Phosphofructokinase
This is otherwise called the bottle neck of Glycolysis.