In glycolysis the first commited step is catalysed by:
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.
2,3 DPG
Glucokinase
Hexokinase
PFK