Category: catabolism
Cytosolic 10-step pathway converting glucose to pyruvate with net 2 ATP + 2 NADH. Three irreversible regulatory steps: hexokinase / glucokinase (hexokinase IV in liver) — glucose phosphorylation; phosphofructokinase-1 (PFK-1) — RATE-LIMITING, allosterically inhibited by ATP + citrate, activated by AMP + F-2,6-BP; pyruvate kinase — final step, allosterically inhibited by ATP + alanine. Tumor cells exhibit aerobic glycolysis (Warburg effect) — high glycolytic flux even with O2 available, supporting biomass over ATP yield. PKM2 isoform dimer/tetramer switching is a major Warburg switch.