During cell respiration food materials are oxidized to carbon dioxide and water in the presence of oxygen. One of the most important fuels is glucose. Under aerobic conditions glucose metabolism takes place in four stages, glycolysis, pyruvic acid oxidation, Krebs citric acid cycle and oxidative phosphorylation in the hydrogen/electron transfer system. During glycolysis there is a glycolytic breakdown of glucose to pyruvic acid. In pyruvic acid oxidation, the pyruvic acid, generated in the glycolysis, enters into the mitochondrial matrix. In Krebs cycle once the pyruvic acid is produced by glycolytic breakdown of glucose in the cytosol, it enters into the mitochondrial matrix.
The respiratory breakdown of glucose in the presence of oxygen is an oxidative process. During this process several intermediates such as phosphoglyceraldehyde, pyruvic acid, iso citric acid, alpha ketoglutaric acid, succinic acid and malic acid are oxidized. Each oxidation step involves release of 2H which goes to reduce various coenzymes namely, NAD+ and FAD. The pair of hydrogen is usually picked from the substrate by NAD+or FAD.
Posted by orchid101
on August 11, 2013 at 5:33 PM (Answer #1)