Stages of Respiration

Aerobic respiration is best understood as four connected stages, each named for its principal chemical transformation and each occurring in a specific part of the cell: (1) glycolysis converts glucose into pyruvic acid in the cytoplasm; (2) the link reaction converts pyruvic acid into acetyl coenzyme-A in the mitochondrial matrix; (3) the Krebs cycle converts acetyl coenzyme-A into carbon dioxide and water, also in the mitochondrial matrix; and (4) the electron transport chain and oxidative phosphorylation strip hydrogen atoms carried by the reduced coenzymes produced in the first three stages, combine them with oxygen to form water, and use the energy released to generate ATP acros …