Lec 7

Question 1

What are enzymes?

Answer 1

Proteins with catalytic activity that speed up chemical reactions in cells.

Question 2

How much do enzymes speed up reactions?

Answer 2

Enzymes speed up reactions by 10^6 to 10^17 times

Question 3

What is the active site of an enzyme?

Answer 3

The region of the enzyme where the substrate binds and the catalytic reaction occurs

Question 4

What are the three basic steps of enzyme-catalyzed reactions?

Answer 4

1. Binding of substrate (E + S → ES)
2. Conversion of bound substrate to bound product (ES → EP)
3. Release of product (EP → E + P)

Question 5

What is induced fit in enzymes?

Answer 5

The process where an enzyme’s active site changes shape to better fit the substrate upon binding

Question 6

What does Vmax represent in enzyme kinetics?

Answer 6

Vmax is the maximum reaction rate when the enzyme is saturated with substrate

Question 7

What does Km (Michaelis constant) represent?

Answer 7

Km is the substrate concentration at which the reaction rate is half of Vmax, indicating the enzyme’s affinity for the substrate

Question 8

What is allosteric regulation?

Answer 8

A form of enzyme regulation where an effector molecule binds to a site other than the active site, inducing a shape change that affects enzyme activity

Question 9

What is feedback inhibition?

Answer 9

A regulatory mechanism where the final product of a metabolic pathway inhibits the first enzyme in that pathway

Question 10

How does pH affect enzyme activity?

Answer 10

Enzymes have an optimal pH for activity. Changes in pH can affect the protonation of amino acid side chains, altering enzyme structure and function

Question 11

How does temperature affect enzyme activity?

Answer 11

Enzymes have an optimal temperature. High temperatures can break non-covalent bonds, causing the enzyme to lose its tertiary structure and denature