CATABOLISMO DE LÍPIDOS. ß-Oxidación de los Ácidos Grasos (Hélice de Lynen)

PDF of the video: http://www.mediafire.com/file/umhxq3v... LIPID CATABOLISM. β-OXIDATION OF FATTY ACIDS (LYNEN HELIX) Once fatty acids are inside the cell, they can undergo β-oxidation, also known as the Lynen Helix, named after its discoverer, the German biochemist Feodor Lynen. Definition: the degradative process of fatty acids through successive oxidations in which Acetyl-CoA molecules are cleaved until complete oxidation. As is common in biochemistry, we will divide the process into several phases for better understanding (since it occurs in a fluid and continuous manner within the cell). 1. ACTIVATION PHASE. This occurs in the cell cytosol and consists of the addition of Coenzyme A to a fatty acid molecule, forming an acyl-CoA. 2. ENTRY INTO THE MITOCHONDRIA. Acyl-CoA cannot cross the mitochondrial membranes, so it requires a transmembrane transport system based on the carnitine shuttle, which is carried out by the enzyme complexes Carnitine Acyltransferase-I and Carnitine Acyltransferase-II, in the outer and inner membranes, respectively. 3. β-OXIDATION OR LYNEN HELIX. This occurs in the mitochondrial matrix. It is further subdivided into several phases: 3.1. Dehydrogenation of acyl-CoA and production of FADH2. 3.2. Hydration with the addition of a water molecule. 3.3. Second dehydrogenation and production of more reducing power, in this case in the form of NADH. 3.4. Fragmentation of 3-Ketoacyl with the release of one molecule of Acetyl-CoA and one molecule of Acyl-CoA with two fewer carbons. These reactions would continue to repeat until the complete degradation of the Acyl-CoA. The YIELD is very high. Thus, for a 16-carbon fatty acid, such as Palmatoyl-CoA, we would obtain: 8 Acetyl-CoA, which in the Krebs cycle + Respiratory Chain yield 96 ATPs. 7 FADH2, which in the respiratory chain yield 14 ATPs. 7 NADH, which in the respiratory chain yield 21 ATPs. A TOTAL of 129 ATPs!!! (If we subtract the equivalent ATP used in the activation of the fatty acid). Don't forget to subscribe to the YouTube channel!!    / eficienciared   You can also follow us on our Facebook page:   / eficiencia.red   I hope this helps you find science more interesting and, above all, easier! :) If you have any questions, feel free to comment!