7.1—Aerobic respiration overview

Aerobic respiration transfers energy from glucose to ATP using oxygen, producing carbon dioxide and water. Glycolysis occurs in the cytoplasm; the link reaction and Krebs cycle occur in the mitochondrial matrix; oxidative phosphorylation occurs on the inner membrane.

Enzymes release energy in controlled steps rather than one burst. NAD and FAD carry hydrogen/electrons between stages, while ATP provides immediately usable energy for cellular work.

A defect in the inner membrane can disrupt electron transport and ATP synthase even if glycolysis in the cytoplasm continues for a time.

The word “energy” is not a product that floats free: it is transferred into ATP and heat. Keep substrate, ATP yield, location and oxygen requirement distinct.