Ethanol → Acetaldehyd occurs in cytosol, microsomes (via CYP2E1 and NADPH), peroxisomes (via catalase and H₂O₂).Acetaldehyde → Acetate occurs in mitochondria.

Fomepizole – inhibits alcohol dehydrogenase and is an antidote for methanol or ethylene glycol poisoning.Disulfiram – inhibits acetaldehyd dehydrogenase (acetaldehyde accumulates, contributing to hangover symptoms), discourages drinking.

- NAD⁺ is the limiting reagent.- Alcohol dehydrogenase operates via zero-order kinetics.

Ethanol metabolism ↑ NADH/NAD⁺ ratio in liver, causing:- Pyruvate → lactate (lactate acidosis)- Oxaloacetate → malate (prevents gluconeogenesis → fasting hypoglycemia)- Dihydroxyacetone phosphate → glycerol-3-phosphate (combines with fatty acids to make triglycerides → hepatosteatosis)- Disfavors TCA production of NADH → ↑ utilization of acetyl-CoA for ketogenesis (→ ketoacidosis) and lipogenesis (→ hepatosteatosis)