Lecture 17

Question 1

A chemical agent that accelerates the rate of a reaction without being changed by the reaction.

Answer 1

Catalyst

Question 2

A non-protein group that binds to the enzyme for catalytic activity.

Answer 2

Cofactor

Question 3

Small organic cofactors which are often
derived from vitamins.

Answer 3

Coenzyme

Question 4

Metal Ions - iron, magnesium, manganese,
cobalt, copper, zinc, and molybdenum.

Answer 4

Common Cofactors

Question 5

NAD+/NADH, FAD+/FADH, vitamins

Answer 5

Common Coenzymes

Question 6

An inactive enzyme.

Answer 6

Apoenzyme

Question 7

An active enzyme with its coenzyme or cofactor bound.

Answer 7

Holoenzyme

Question 8

What determines the function of an enzyme?

Answer 8

Structure

Question 9

What do substrates produce in a reaction?

Answer 9

Products

Question 10

What are the functions of cofactors and coenzymes?

Answer 10

To help an enzyme become active and work better

Question 11

What does an enzyme need to be active?

Answer 11

A cofactor or a coenzyme

Question 12

What factors affect enzyme activity?

Answer 12

1) Concentration of a substrate
2) Temperature and pH levels
3) Control mechanisms

Question 13

Which mechanisms regulate enzymes?

Answer 13

1) Competitive and Noncompetitive regulation
2) Allosteric Regulation

Question 14

Non-substrate molecules that bind to an enzyme and decrease its activity

Answer 14

Enzyme Inhibitors

Question 15

Molecules reassemble the substrate and compete for the active site (substrate is unable to bind)

Answer 15

Competitive Inhibition

Question 16

Molecule binds at a site other than the active site, slightly changing the active site’s shape. The substrate is able to bind, but the reaction is blocked

Answer 16

Noncompetitive Inhibition

Question 17

Any site on an enzyme besides the active site

Answer 17

Allosteric Site

Question 18

What does allosteric regulation do?

Answer 18

Makes an enzyme work better or not at all

Question 19

The enzyme binds strongly to its substrate through allosteric activator

Answer 19

High Affinity State

Question 20

The enzyme binds the substrate weakly or not all through allosteric inhibitors

Answer 20

Low Affinity State

Question 21

Excess product binds to an allosteric site which inhibits the enzyme and stops activity

Answer 21

Negative Feedback Inhibition

Question 22

Excess product binds to an allosteric site which activates the enzyme and continues the activity

Answer 22

Positive Feedback Inhibition