Which alcohol dehydrogenase (ADH) metabolic pathway is primarily responsible for the oxidation of ethanol to acetaldehyde?

The correct choice is alcohol dehydrogenase (ADH) because this enzyme plays a pivotal role in the metabolism of alcohol in the human body. During the process of alcohol metabolism, ADH catalyzes the oxidation of ethanol, converting it to acetaldehyde. This is a crucial step because acetaldehyde is a toxic byproduct that can lead to various negative health effects if it accumulates.

In this metabolic pathway, ADH uses NAD+ as a cofactor to help in the oxidation reaction, and it is primarily located in the liver. Once ethanol is converted to acetaldehyde by ADH, further metabolism occurs, typically involving aldehyde dehydrogenase (ALDH), which converts acetaldehyde into acetate. This makes ADH the principal enzyme in the initial step of ethanol metabolism leading to acetaldehyde production.

Understanding the role of ADH is essential, especially considering how variations in this enzyme's activity can influence individuals' tolerance to alcohol and their vulnerability to alcohol-related disorders.