Topic 21Biology

C1.2 Cell respiration

ATP as the cell's energy currency. Aerobic vs anaerobic respiration in humans (substrates, locations, ATP yields, waste products). HL: glycolysis as a 10-step pathway with 4 phases; lactate/ethanol fermentation regenerate NAD⁺. Link reaction + Krebs cycle in the matrix; electron transport chain pumps H⁺ to generate a gradient that drives ATP synthase (chemiosmosis); O₂ is the terminal electron acceptor. Lipids yield ~2× ATP per gram of carbohydrate.