Alcohol dehydrogenase (ADH) is an enzyme found in all living things, including humans, that plays an important role in the metabolism of alcohol or ethanol. It is a member of an enzyme family that catalyzes the oxidation of alcohols to aldehydes or ketones by using nicotinamide adenine dinucleotide (NAD+) as a cofactor. ADH is mostly found in the liver, but it is also found in the stomach and the lining of the gastrointestinal tract in humans. Its primary function is to convert ethanol, the intoxicating component of alcoholic beverages, to acetaldehyde. This first step in alcohol metabolism takes place in the cytoplasm of liver cells. ADH catalyzes the transfer of a hydrogen atom from ethanol to the NAD+ coenzyme, which results in the reduction of NAD+ to NADH. Concurrently, ethanol is reduced to acetaldehyde: Acetaldehyde + NADH + H+ + Ethanol + NAD+ Although less poisonous than ethanol, acetaldehyde is nevertheless a dangerous chemical that can cause nausea, headaches, and an elevated heart rate in the body. Fortunately, another enzyme known as aldehyde dehydrogenase (ALDH) converts acetaldehyde to acetate, which is then transformed into innocuous compounds like as water and carbon dioxide. Individuals' ADH activity varies, which determines how rapidly they metabolize alcohol. Genetic variables can influence ADH enzyme efficiency, contributing to variances in alcohol tolerance and susceptibility to alcohol-related disorders between groups. The rate of alcohol metabolism is relatively consistent and follows zero-order kinetics, which means that the enzyme acts at maximum capacity, breaking down ethanol at a constant pace regardless of blood alcohol levels. As a result, excessive alcohol consumption can overwhelm ADH and result in acetaldehyde accumulation, producing pain and contributing to intoxication symptoms. Understanding the role of alcohol dehydrogenase in ethanol metabolism has important consequences for alcohol intake, alcohol-related diseases, and the development of treatments to reduce the harmful effects of alcohol on the human body. ADH continues to be a focus of alcohol research, revealing light on its complex mechanisms and potential therapeutic strategies.
