The reactions of deamination amino acids, regenerative amination an alpha-keton acids in
Animals.
Deamination is the removal of an amine group from a molecule. Enzymes that catalyse this reaction are called deaminases.
In the human body, deamination takes place primarily in the liver, however glutamate is also deaminated in the kidneys. Deamination is the process by which amino acids are broken down if there is an excess of protein intake. The amino group is removed from the amino acid and converted to ammonia. The rest of the amino acid is made up of mostly carbon and hydrogen, and is recycled or oxidized for energy. Ammonia is toxic to the human system, and enzymes convert it to urea or uric acid by addition of carbon dioxide molecules (which is not considered a deamination process) in the urea cycle, which also takes place in the liver. Urea and uric acid can safely diffuse into the blood and then be excreted in urine.
Keto acids or ketoacids (also called oxo acids or oxoacids) are organic compounds that contain a carboxylic acid group and a ketone group.[1] In several cases, the keto group is hydrated. The alpha-keto acids are especially important in biology as they are involved in the Krebs citric acid cycleand in glycolysis.[2]
Common types of keto acids include:
· Alpha-keto acids, or 2-oxoacids, such as pyruvic acid, have the keto group adjacent to the carboxylic acid. Another important member isoxaloacetic acid, a component of the Krebs cycle.[3] Alpha-ketoglutarate, (also known as 2-oxo glutarate) is a 5-carbon keto acid derived from glutamic acid. Alpha-ketoglutarate participates in cell signaling by functioning as a cofactor for a variety of iron-containing redox enzymes, for example the proline hydroxylases that modify the hypoxia inducible factor leading to the destruction of HIF except in hypoxia when this pathway is blocked.[4]
· Beta-keto acids, or 3-oxoacids, such as acetoacetic acid, have the ketone group at the second carbon from the carboxylic acid
· Gamma-keto acids, or 4-oxoacids, such as levulinic acid, have the ketone group at the third carbon from the carboxylic acid.
When ingested sugars and carbohydrate levels are low, stored fats and proteins are the primary source of energy production. Glucogenic amino acidsfrom proteins are converted to glucose and fats can be used to form ketone bodies. Ketogenic amino acids can be deaminated to produce alpha keto acids and ketone bodies.
Alpha keto acids are used primarily as energy for liver cells and in fatty acid synthesis, also in the liver.
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