Why does the enzyme alcohol dehydrogenase only break down et

Why does the enzyme alcohol dehydrogenase only break down ethanol in a specific temperature range? Explain in detail what occurs at the enzyme and substrate level.

Solution

Alcohol dehydrogenase (ADH) refers to a family of enzymes which catalyse the reversible oxidation of primary or secondary alcohols to aldehydes or ketones respectively. ADH has many roles in the body, a major function is to catalyse the oxidation of ethanol to acetaldehyde as the first step of ethanol metabolism by the liver, using NAD+ or NADP+ as electron acceptors in the process.

ADH enzymes are found in almost every living organism as ethanol is a prominent organic compound present naturally in the environment due to processes such as fermentation. Although the reaction is reversible, some types of alcohol dehydrogenase favour the forward reaction, while others favour the reverse. Alcohol dehydrogenase is also involved in the toxicity of other types of alcohol. For instance, it oxidizes methanol to produce formaldehyde and ethylene glycol to ultimately yield glycolic and oxalic acids.