Question

Mutations are known to exist in the ALDH2 gene, which codes for the ALDH enzyme. The most common mutation leads to a substitution of lysine for glutamate at position 504. This substitution leads to a nearly inactive ALDH enzyme. People carrying this mutation show a reaction when they consume even very small amounts of alcohol. Symptoms of their reaction include: a flushed appearance, nausea, and an irregular heartbeat.

Why does this mutation have such an effect?

a. An inactive ALDH enzyme prevents the conversion of acetate to acetaldehyde

b. An inactive ALDH enzyme would prevent the breakdown of acetate to carbon dioxide and water which prevents the elimination of the byproducts of alcohol from the body

c. The single amino acid substitution of lysine to glutamate at position 504 leads to a change in the primary structure of the ALDH enzyme, which then cannot catalyze the breakdown of alcohol to acetaldehyde

d. The mutation to the ALDH2 gene leads to the inactivity of ALDH, thereby preventing the breakdown of acetaldehyde, which is toxic to tissues
Monet

Answer 1

d. The mutation to the ALDH2 gene leads to the inactivity of ALDH, thereby preventing the breakdown of acetaldehyde, which is toxic to tissues.

Step-by-step explanation:

In individuals with the ALDH2 gene mutation that leads to an inactive ALDH enzyme, acetaldehyde, a toxic byproduct of alcohol metabolism, cannot be efficiently broken down into a non-toxic substance (acetic acid). This accumulation of acetaldehyde in the body can lead to the symptoms described, including a flushed appearance, nausea, and an irregular heartbeat, as acetaldehyde is toxic to tissues and can cause these adverse reactions. This mutation impairs the body's ability to metabolize acetaldehyde, leading to these negative effects when alcohol is consumed.

Answer 2

The inactive ALDH enzyme in people carrying the mutation prevents the breakdown of acetate, leading to the accumulation of acetaldehyde and symptoms such as a flushed appearance, nausea, and an irregular heartbeat.

Step-by-step explanation:

The correct answer is b. An inactive ALDH enzyme would prevent the breakdown of acetate to carbon dioxide and water which prevents the elimination of the byproducts of alcohol from the body.

The ALDH enzyme is responsible for converting acetaldehyde, a toxic byproduct of alcohol metabolism, into acetate. This mutation results in an inactive ALDH enzyme, which means that acetaldehyde is not efficiently broken down into acetate. As a result, acetaldehyde builds up in the body, leading to symptoms such as a flushed appearance, nausea, and an irregular heartbeat when alcohol is consumed.