Alcohol dehydrogenase

Alcohol dehydrogenases are enzymes that oxidize alcohols to aldehydes or ketones, often transferring hydrogen to NAD⁺ or NADP⁺. They occur across organisms and differ in structure, cofactors, and substrate range.

Nicotinamide adenine dinucleotide: NAD is a coenzyme that carries electrons in cellular oxidation–reduction reactions. NAD⁺ accepts a hydride during many alcohol dehydrogenase reactions.
Alcohol (chemistry): An alcohol is an organic compound with a hydroxyl group bonded to a saturated carbon atom. Alcohols are the substrates whose oxidation gives the enzyme family its name.
Ethanol metabolism: Ethanol metabolism is the biochemical conversion of ethanol into acetaldehyde, acetate, and ultimately carbon dioxide and water. Alcohol dehydrogenase performs the first major step of ethanol breakdown in humans.
Aldehyde dehydrogenase: Aldehyde dehydrogenase oxidizes aldehydes to carboxylic acids, commonly using NAD⁺ or NADP⁺. It acts on acetaldehyde downstream of alcohol dehydrogenase in ethanol metabolism.
Hydride transfer: Hydride transfer is the movement of a hydrogen atom with both bonding electrons between chemical species. Alcohol dehydrogenases commonly oxidize substrates by transferring a hydride to NAD⁺.
Ethanol: Ethanol is a two-carbon alcohol found in alcoholic beverages and produced by fermentation. It is a common substrate for mammalian and microbial alcohol dehydrogenases.
Alcoholic fermentation: Alcoholic fermentation is the microbial conversion of sugars into ethanol and carbon dioxide. In fermenting yeast, an alcohol dehydrogenase regenerates NAD⁺ by converting acetaldehyde to ethanol.
Catalase: Catalase is an enzyme that decomposes hydrogen peroxide into water and oxygen. Catalase can also oxidize ethanol, but uses hydrogen peroxide rather than NAD⁺ as the oxidant.
Zinc: Zinc is a chemical element whose ions serve structural and catalytic roles in proteins. In many alcohol dehydrogenases, zinc helps bind the alcohol substrate and stabilize reaction intermediates.
Acetaldehyde: Acetaldehyde is a volatile two-carbon aldehyde formed during ethanol oxidation. It is the immediate product when alcohol dehydrogenase oxidizes ethanol.

Linked from 11 pages