The Chemiosmotic Theory of Oxidative Phosphorylation involves the movement of protons (H+) from the mitochondrial matrix to the intermembranal space, which has a high concentration of H+. The mitochondrial matrix, on the other hand, has a low concentration of H+. This creates an electrochemical gradient that is essential for the production of ATP.
Oxidative Phosphorylation Steps
Oxidative Phosphorylation occurs in the mitochondrial matrix. During this process, NADH and FADH donate electrons which are then passed down the electron transport chain. As a result, protons are transported across the membrane, and electrons combine with protons and oxygen to form water. The production of ATP from ADP + Pi is powered by the diffusion of protons back into the mitochondrial matrix through ATP synthase.
ATP Production
32 ATP are produced in Aerobic Respiration. This includes 28 ATP made from oxidative phosphorylation, 2 ATP from glycolysis, and 2 ATP from the Krebs cycle.
Oxidative Phosphorylation Products
In oxidative phosphorylation, 2.5 ATP are made from each NADH, while 1.5 ATP are made from each FADH, resulting in a total of 28 ATP made from oxidative phosphorylation.
Aerobic Respiration ATP Production Notes
The movement of protons into the intermembranal space and the production of ATP from ADP + Pi are crucial components of aerobic respiration and its ATP production.
Anaerobic Respiration
In contrast to aerobic respiration, there is also the process of anaerobic respiration. During anaerobic respiration, 2 ATP are produced from glycolysis, and the terminal acceptor in the electron transport chain is a molecule other than oxygen, such as sulfate or nitrate.
Furthermore, alternative respiratory substrates can enter the Krebs cycle and contribute to ATP production. These substrates include the breakdown products of lipids and amino acids.
Respiration of Lipids
When lipids are hydrolyzed, they produce glycerol and fatty acids. The glycerol is phosphorylated and then converted to TP, while the fatty acids are broken down into 2-carbon fragments that are converted to acetyl coA, which enters the Krebs cycle. This process releases 2x the energy of carbohydrates and also produces many hydrogen atoms for oxidative phosphorylation.
Respiration of Protein
Amino acids are hydrolyzed and deaminated, and the resulting 3-carbon compounds are converted to pyruvate, while 4- and 5-carbon compounds are converted to intermediates in the Link Reaction and Krebs cycle.
In summary, the chemiosmotic theory of oxidative phosphorylation is a fundamental concept in cellular respiration, explaining the interplay of various cellular components and the production of ATP. Understanding the steps and products of oxidative phosphorylation is crucial in comprehending the differences between aerobic and anaerobic respiration and the overall process of cellular respiration. For more detailed information about the Chemiosmotic Theory of Oxidative Phosphorylation, you can refer to the Chemiosmotic Theory of Oxidative Phosphorylation PDF and/or the Oxidative Phosphorylation PPT.
