The hydration step Essay Example for Free

The hydration tempo EssayOxidation is the major alley for the catabolism of saturated fatty acidulents. It involves the successive removal of two-carbon fragments from the carboxyl end of the fatty acyl CoA (Champe, Harvey, Ferrier, 2005). The starting signal three tempos of this ? - oxidization spiral are the following (Murray, Granner, Mayes, Rodwell, 2000) De heat contentation or oxidation the removal of two hydrogen atoms from the 2(? )- and 3(? )-carbon atoms, catalyzed by acyl-CoA dehydrogenase, yielding 1 FADH2 Hydration the profit of water to saturate the double bond, forming 3-hydroxyacyl-CoA, catalyzed by ?2-enoyl-CoA hydrase (also known as enoyl-CoA hydratase) and Dehydrogenation or oxidation a further dehydrogenation on the 3-carbon, catalyzed by the enzyme L(+)-3-hydroxyacyl-CoA dehydrogenase, producing 1 NADH. The end-products of this pathway, after a a couple of(prenominal) more steps and successive reentry of acyl-CoA into the make pass, are acetyl C oA, NADH and FADH2. The citric acid make pass is the energy-producing pathway where the aerophilic metabolism of carbohydrates, amino acids, and fatty acids converge, their carbon skeletons being converted to CO2 and H2O (Champe, Harvey, Ferrier, 2005).Although it is technically a cycle, the last three steps are identified as follows (Murray, Granner, Mayes, Rodwell, 2000) Dehydrogenation or oxidation succinate, in the presence of FAD, is converted by the enzyme succinate dehydrogenase into fumarate and FADH2 Hydration the addition of water to fumarate to produce L-malate, catalyzed by fumarate hydratase (also known as fumarase) and Dehydrogenation or oxidation the conversion of malate and NAD+ by the enzyme malate dehydrogenase to oxaloacetate, NADH and H+.The chemical conversions involved in the citric acid cycle that eventually produce carbon dioxide and water generate a form of energy that is usable by aerobic organisms (http//en. wikipedia. org/wiki/Citric_acid_cycle). Obviously, the first three steps of the ? -oxidation pathway and the last three steps of the citric acid cycle involve the same reactions. Both occur in the mitochondria of the cell. In both cycles, the first dehydrogenation (also called oxidation, depending on the source) involves a flavoprotein coenzyme with a FAD prosthetic group, and FADH2 is thus yielded.The hydration step in ? -oxidation and the citric acid cycle involve hydratase enzymes. The second dehydrogenation step in both cycles require the NAD+ coenzyme and produce NADH + H+. That having been said, the principal(prenominal) difference between these otherwise similar reactions is that they have different substrates and yield different products. The last step in the ? -oxidation pathway is the splitting of ? -ketoacyl-CoA by the enzyme ? -ketothiolase (http//themedicalbiochemistrypage. org/fatty-acid-oxidation. html).This reaction produces an acyl-CoA derivative that contains two carbons less than the original acyl-CoA jot that that underwent oxidation, as well as acetyl-CoA. The acyl-CoA thus formed reenters the ? -oxidation spiral, while the acetyl-CoA is oxidized to carbon dioxide and water done the citric acid cycle. The first step of the citric acid cycle is the initial condensation of acetyl-CoA with oxaloacetate to form citrate, in a reaction catalyzed by citrate synthase (Murray, Granner, Mayes, Rodwell, 2000). A carbon-to-carbon bond is created between the methyl radical group of acetyl-CoA and the carbonyl carbon of oxaloacetate.Acetyl-CoA transfers its two-carbon acetyl group to oxaloacetate, which initially contains four carbons, and a six-carbon molecule is consequently formed as citrate (http//en. wikipedia. org/wiki/Citric_acid_cycle). Both reactions involve acetyl-CoA. However, acetyl-CoA is the product in ? -oxidation, whereas it is one of the substrates in the citric acid cycle. Coenzyme A is required in the last step of ? -oxidation, whereas it is one of the by-products in the first step of the citric acid cycle. Finally, in ? -oxidation, two carbons are removed per cycle, whereas the citric acid cycle involves the addition of two carbons.References Champe, P. C. , Harvey, R. A. , Ferrier, D. R. (2005). Lippincotts Illustrated Reviews Biochemistry. Philadelphia Lippincott Wiliams Wilkins. Citric Acid Cycle. (2008). In Wikipedia, the free encyclopedia. Retrieved October 7, 2008, from Wikipedia http//en. wikipedia. org/wiki/Citric_acid_cycle Fatty Acid Oxidation. (2008). In The medical Biochemistry Page. Retrieved October 7, 2008, from http//themedicalbiochemistrypage. org/fatty-acid-oxidation. html Murray, R. K. , Granner, D. K. , Mayes, P. A. , Rodwell, V. W. (2000). Harpers Biochemistry (25th ed. ). New York McGraw-Hill.