Question

Methanol and ethanol are oxidized by alcohol dehydrogenase. In methanol poisoning, ethanol is given intravenously to prevent the formation of formaldehyde that has toxic effects.

a. Draw the condensed structural formulas for methanol and ethanol.

b. Would ethanol compete for the active site or bind to a different site?

c. Would ethanol be a competitive or noncompetitive inhibitor of alcohol dehydrogenase?

Short answer

(Part a) Methanol has one carbon, whereas ethanol has two carbons.

(Part b) Even though ethanol has a structure similar to methanol, it can start competing for the active site on alcohol dehydrogenase.

(Part c) Ethanol will compete with methanol to inhibit its oxidation.

Step-by-step solution

Introduction (Part a).

Dehydrogenases are enzymes that catalyze reduction reactions by moving hydrogen ions (protons) from the substrate to a co-enzyme or acceptor.

Given Information (Part a).

Alcohol dehydrogenase oxidizes methanol and ethanol. In methanol poisoning, ethanol is given intravenously to prevent the formation of toxic formaldehyde.

Sketch the methanol and ethanol structural formulas in condensed form.

Explanation (part a).

Methanol has one carbon, whereas ethanol has two carbons.

Given Information (Part b).

Alcohol dehydrogenase oxidizes methanol and ethanol. In methanol poisoning, ethanol is given intravenously to prevent the formation of toxic formaldehyde.

Ethanol can either compete for the active center or bind to a different site.

Explanation (part b).

Even though ethanol has a structure similar to methanol, it can start competing for the active site on alcohol dehydrogenase.

Given Information (Part c).

Alcohol dehydrogenase oxidizes methanol and ethanol. In methanol poisoning, ethanol is given intravenously to prevent the formation of toxic formaldehyde.

Alcohol dehydrogenase inhibition by ethanol can be competitive or noncompetitive.

Explanation (part c).

Ethanol will compete with methanol to inhibit its oxidation.