Glycolysis

Hexokinase

Converts glucose to glucose-6-phosphate, coupled with ATP → ADP

Phosphoglucoisomerase

Converts glucose-6-phosphate to fructose-6-phosphate

Phosphofructokinase

Converts F6P to fructose-6-bisphosphate → rate limiting step, irreversible; coupled with ATP → ADP

Aldolase

Cleaves F6BP into glyceraldehyde-3-phosphate & di-hydroxyacetone phosphate

TPI

Converts DHAP to GAP

GAPDH

Converts GAP to 1,3-bisphosphoglycerate; coupled with NAD+ → NADH; total yield: 2 NADH

Phosphoglycerate kinase

Converts 1,3-BPG into 3-phosphoglycerate (X2); coupled with ADP → ATP per GAP converted to 3-PG = +2 ATP

Phosphoglycerate mutase

Converts 3-PG to 2-PG

Enolase

Mg²⁺ cofactor required; 2-PG converted to phophoenolpyruvate via dehydration

Pyruvate Kinase

Final step: PEP converted to pyruvate by moving a phosphate group from PEP to ADP → ATP