INTRODUCTION Many metabolic enzymes work as teams, where the product of one enzy

Question

INTRODUCTION Many metabolic enzymes work as teams, where the product of one enzyme becomes the substrate for another enzyme. In this recitation, you will study two enzymes used in the metabolism of alcohols, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH. Without these enzymes, humans would not be able to consume alcohol, which is poisonous. In the first step, ADH, found primarily in the liver, converts alcohols to al dehydes by removing H atoms. Aldehydes are still toxic to humans, so a second step is required. ALDH, found in mitochondria, converts aldehyde to acetate. The figure below shows how the two enzymes work together. ADH ALDH ethanol acetaldehyde acetate Figure 1: Enzymatic reaction converting ethanol to acetate What term describes a reaction like this, where electrons are moved between molecules? Do you think that the structure of ADH or ALDH change as a result of this reaction?

Explanation / Answer

Given reaction,

Ethanol ------> Acetaldehyde ----> Acetate

These are oxidation reactions (Redox reactions).

Oxidation refers to

i. Loss of hydrogen atoms

ii. The gain of oxygen atoms

iii. Increase in oxidation number

The above reactions are catalyzed by ADH and ALDH respectively. Enzymes are biocatalysts. They accelerate the reaction rate without being used up. At the end of the reaction, they do not change their shape or composition.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.