Enzyme Mechanisms and Classifications Chapter 17

These flashcards cover key concepts related to enzyme mechanisms, classifications, and reaction types, providing a comprehensive review for exam preparation.

What is the role of the active site in an enzyme?

The active site is the region on the enzyme where substrate binding occurs and where the catalytic reaction takes place.

What is an enzyme-substrate complex?

It is the transient molecule formed when an enzyme binds its substrate.

Name the six classifications of enzymes according to reaction type.

1. Oxidoreductases 2. Transferases 3. Hydrolases 4. Lyases 5. Isomerases 6. Ligases.

What type of reaction do oxidoreductases catalyze?

Oxidation-reduction reactions.

What is the transition state in reaction mechanisms?

The transition state is an unstable state during a chemical reaction through which reactants must pass before forming products.

In the mechanism of ribonuclease, which bond is broken?

The phosphodiester bond of the RNA backbone.

What is the catalytic triad in chymotrypsin?

The catalytic triad consists of Asp 102, His 57, and Ser 195, which are crucial for the enzyme's catalytic activity.

What is the result of a nucleophilic attack in enzyme mechanisms?

It forms a tetrahedral intermediate in the reaction mechanism.

What type of reactions do hydrolases catalyze?

Hydrolysis reactions.

What is the purpose of an oxyanion hole in enzyme catalysis?

The oxyanion hole stabilizes the transition state of the tetrahedral intermediate by forming hydrogen bonds with the negatively charged oxygen.