Final answer:
The metabolism of ethanol begins in the stomach with the help of alcohol dehydrogenase, converting it into less harmful substances. Food in the stomach can slow this absorption, while the liver predominantly metabolizes the alcohol, excreting excess through urine, sweat, and breath.
Step-by-step explanation:
When you drink an alcoholic beverage, metabolism of the ethanol starts in the stomach, where the enzyme alcohol dehydrogenase and other enzymes break down some of the alcohol into acetaldehyde, then to acetate, and eventually into carbon dioxide and water. Since some of the alcohol is absorbed in the stomach, food there will slow the absorption of alcohol into the bloodstream. Most of the alcohol is absorbed in the small intestine and carried to the liver, where most of the alcohol is metabolized. However, the liver can only metabolize one standard drink per hour. The additional alcohol, not metabolized by the liver, enters the bloodstream and travels throughout the body.
It can be excreted in the urine, sweat, and breath. As unmetabolized alcohol reaches the brain, the individual will become intoxicated.