Aldehyde Dehydrogenase 1

The video tutorial explores the mechanism of aldehyde dehydrogenases, enzymes crucial in amino acid catabolism and ethanol metabolism. It details the steps of the mechanism, including nucleophilic attack, intermediate formation, and hydrolysis, highlighting the role of cysteine thiolate and glutamate. The tutorial also discusses the generation of reduced cofactors NADH or NADPH and mentions inferred steps in the mechanism. Variations with different nucleophiles, such as phosphate, are also covered.

What is the primary role of aldehyde dehydrogenases in ethanol metabolism?

• To metabolize acetaldehyde into acetic acid

• To convert ethanol directly into water

• To increase the concentration of ethanol in the body

• To prevent the formation of acetaldehyde

In the initial step of the aldehyde dehydrogenase mechanism, what occurs after the nucleophilic attack?

• Direct conversion to a carboxylic acid

• Generation of a tetrahedral intermediate

• Immediate release of the product

• Formation of a stable complex

Which cofactor is specifically used by acetaldehyde dehydrogenase?

• NAD+

• NADP+

• FAD

• Coenzyme A

What is the result of the hydride transfer in the aldehyde dehydrogenase mechanism?

• Reduction of the cofactor

• Formation of a new aldehyde

• Release of a water molecule

• Oxidation of the substrate

What is the inferred step in the final part of the aldehyde dehydrogenase mechanism?

• Direct formation of a carboxylic acid

• Deprotonation by water to regenerate glutamate

• Formation of a stable ester

• Immediate release of the thiolate

How does the aldehyde dehydrogenase mechanism affect pH?

• It stabilizes pH by buffering the solution

• It has no effect on pH

• It decreases pH by increasing hydronium concentration

• It increases pH by releasing hydroxide ions

What is the role of glutamate in the active site of aldehyde dehydrogenases?

• To act as a nucleophile

• To deprotonate water

• To stabilize the substrate

• To release the final product