Respiration

• NAD+ and FAD+ are coenzymes of oxidation-reduction in cellular respiration.
• 1. Glycolysis: The breakdown of 2 glucose molecules to produce 2 pyruvate molecules. It is an anaerobic stage and occurs in the cytoplasm.
• 2. Link reaction: Two pyruvate molecules will become two acetyl CoA molecules. This reaction, however, is aerobic and occurs in the matrix.
• 3. Krebs cycle: Acetyl coenzyme A combines with a 4C compound, oxaloacetate to form a 6C compound, citrate. It happens in the matrix of the mitochondria and is also aerobic.
• 4. Electron transport chain: NADH and FADH2 give up their energetic electrons to the electron transport chain. Oxygen combines with hydrogen ions and electrons forming water. It occurs in the inner mitochondrial membrane and is aerobic.
• Chemiosmosis: ATP is formed as a direct result of the net movement of protons flowing through the channel protein, ATP synthase down their gradient by facilitated diffusion from the intermembrane space back into the matrix. It occurs in the ETC.