BIOL 1012 Lecture Notes - Lecture 20: Oxidative Phosphorylation, Cellular Respiration, Electron Transport Chain
Document Summary
Cellular respiration occurs in three mains stages: cellular respiration consists of a sequence of steps that can be divided into three stages. Breaks down glucose into two molecules of a three- carbon compound called pyruvate. Stage 2; pyruvate oxidation and the citric acid cycle. Cell makes a small amount of atp during glycolysis and citric acid cycle. Nadh and a related electron carrier, gadh2, shuttle electrons to an electron transport chain embedded in the inner mitochondrial membrane. Most atp produced by cellular respiration is generated by oxidative phosphorylation, which uses the energy released by the downhill fall of electrons from nadh and fadh2 to oxygen to phosphorylate. As the electron transport chain passes electrons down the energy hill, it also pumps hydrogen ions across the inner mitochondrial membrane, into the narrow intermembrane space, and produces a concentration gradient of h+ across the membrane. In chemiosmosis, the potential energy of this concentration gradient is used to make atp.