Glycolysis (EMP pathway), gluconeogenesis, fermentation, Warburg effect, pentose-phosphate bypass.
Glycolysis And Gluconeogenesis
Glycolysis (Embden-Meyerhof-Parnas)
Ten-step cytoplasmic pathway converting glucose → 2 pyruvate with net +2 ATP and +2 NADH. Universal across domains of life; hexokinase,…
Hexokinase / glucokinase
Enzyme committing glucose to metabolism: glucose + ATP → glucose-6-P + ADP. Isoforms: hexokinase (muscle, K_M ≈ 0.1 mM), glucokinase…
Phosphofructokinase-1 (PFK-1)
Committed step of glycolysis: F6P + ATP → F1,6-BP + ADP. Major regulatory enzyme: allosterically activated by AMP, F2,6-BP; inhibited by…
Pyruvate kinase
Glycolytic step 10: PEP + ADP → pyruvate + ATP (substrate-level phosphorylation). Allosterically activated by F1,6-BP (feed-forward);…
Gluconeogenesis
Reverse-glycolysis pathway generating glucose from pyruvate/lactate/glycerol/glucogenic AAs. Bypasses three irreversible glycolytic steps…
Cori cycle
Interorgan cycle: muscle glycolysis → lactate → liver gluconeogenesis → glucose → muscle. Shifts metabolic cost of ATP production to the…
Lactic fermentation
Anaerobic regeneration of NAD+ from NADH by lactate dehydrogenase: pyruvate + NADH → lactate + NAD+. Allows glycolysis to continue when O2…
Warburg effect
Aerobic glycolysis in rapidly proliferating cells (especially cancer): preference for lactate fermentation over oxidative phosphorylation…
Pentose phosphate pathway
Glucose-6-P oxidative branch producing NADPH (for biosynthesis/antioxidant defence) and ribose-5-P (nucleotide synthesis). Oxidative phase…
Fed/fasted glucose regulation
Insulin (fed) activates glycogen synthesis, glycolysis; glucagon (fasted) activates glycogenolysis, gluconeogenesis. Liver maintains blood…