Physiology, Krebs Cycle
Tamim Omar Alabduladhem, Bruno Bordoni
Abstract
The tricarboxylic acid (TCA) cycle, also known as the Krebs cycle or citric acid cycle, is an important cell's metabolic hub. It is composed of eight enzymes, all of which are within the mitochondrial matrix except the outlier succinate dehydrogenase, which is related to the respiratory chain on the inner mitochondrial membrane. The cycle serves as a gateway for aerobic metabolism for molecules that can convert to an acetyl group or dicarboxylic acid. Regulation of the TCA cycle occurs at three distinct points that include the three following enzymes: citrate synthase, isocitrate dehydrogenase, and alpha-ketoglutarate dehydrogenase. The cycle also plays a role in replenishing precursors for the storage form of fuels such as amino acids and cholesterol.