A 40-Year-Old Manager, at a Prominent Legal Firm in L

A 40-year-old manager, at a prominent legal firm in L.A., experiences abdominal pain post lunch. He goes to the restroom a couple of times, but continues to experience pain and cramps. He eventually decides to get himself examined. While questioning him, you learn that he consumed two bottles of beer at lunch. The alcohol (ethyl alcohol/ethanol) content in a bottle of beer is about 5%. The man's weight is 150 lbs and he was drinking over an hour period. State the chemical reaction that took place in the patient’s body. Identify the substance produced in the liver that helps catalyze this reaction.

Beer contains ethyl alcohol, whose chemical formula is CH3CH2OH.Ethanol is poisonous to the body and the body starts to remove it quickly. Most of the removal is done by the liver.

The first step is an oxidation reaction that converts ethanol to acetaldehyde (CH3COH). This reaction is catalyzed by a substance called alcohol dehydrogenase. The reaction is written as:

CH3CH2OH CH3COH + 2H

However, acetaldehyde (CH3COH) is also poisonous. So in a second step anotheroxidation reaction occurs that converts the acetaldehyde to acetate. This second reaction is catalyzed by the substance aldehyde dehydrogenase. The reaction is written as:

CH3COH + H2O CH3COO- + 3H

A 150 lb human body can remove ethanol at the rate of about 0.5 oz. per hour. One bottle of beer contains about 0.6 oz. of ethanol (12 oz. x 5%). Since the manager consumed 2 bottles of beer he ingested 1.2 oz. of ethanol in one hour. This is more than his body can naturally dispose of and may have caused his problems.

References

Shakhashiri, B. (2009, Feb. 5). Chemical of the Week : Ethanol. Retrieved from

Pawan, G. L. S. (1972). Metabolism of Alcohol in Man.Proceedings of Nutrition Society, 31, 83 – 89.