Enzyme Kinetics

Question 1

Enzymes speed up reactions by

Answer 1

Lowering the AE of the reaction

Question 2

What is the equation of rate?

Answer 2

Rate = k[reactants]

Question 3

How can you increase the rate of a reaction?

Answer 3

• Increase substrate concentration

- Increase enzyme concentration

Question 4

Vmax lets us know that

Answer 4

At really high concentrations of substrate, enzyme will be saturated and full of substrate

Question 5

At Vmax, the enzyme will not be able to

Answer 5

React any more quickly

Question 6

Protein synthesis or degradation does not change

Answer 6

Enzyme concentration

Question 7

Environmental factors like changes in temperature do not influence

Answer 7

The rate constant K

Question 8

The Steady-State Assumption is

Answer 8

At a concentration where enzyme-substrate complex is constant

Question 9

What is the Michaelis-Menten Equation?

Answer 9

Vo = (Vmax [S]) / (Km + [S])

Question 10

Km is the

Answer 10

Michaelis Constant

Question 11

Km is the concentration of

Answer 11

Substrate at which reaction speed is 1/2Vmax

Question 12

The lower the Km is the

Answer 12

Better our enzyme works

Question 13

The Michaelis Constant can be used to

Answer 13

Quantify enzyme’s ability to catalyze reactions (called Catalytic Efficiency)

Question 14

What is the equation for Catalytic Efficiency?

Answer 14

Kcat / Km

Question 15

A covalent catalysis involves the

Answer 15

Sharing of electrons between two molecules

Question 16

Proximity or orientation catalysis involves the

Answer 16

Rearrangement of molecular bonds by the basic collision of two molecules together

Question 17

Keto-enol tautomerization is what kind of catalysis?

Answer 17

Acid/Base catalysis

Question 18

What happens during competitive inhibition?

Answer 18

• Km changes

- Vmax stays constant

Question 19

What happens during uncompetitive inhibition?

Answer 19

• Km decreases

- Vmax decreases

Question 20

What happens during noncompetitive inhibition?

Answer 20

• Km stays constant

- Vmax decreases

Question 21

Enzymes increase the rate of a reaction by

Answer 21

Stabilizing the transition state

Question 22

What is Allosteric Inhibition?

Answer 22

The binding of a ligand to a protein outside of the active site

Question 23

Uncompetitive inhibition involves the binding of an

Answer 23

Inhibitor to both the free enzyme and enzyme-substrate complex

Question 24

What happens in feedback inhibition?

Answer 24

The product of a reaction inhibits the enzyme that helped produce it

Question 25

A low Km indicates

Answer 25

Higher affinity for substrate

Question 26

Which enzyme would be more easily saturated?

Answer 26

One with a lower Km

Question 27

Compared to substrates, enzymes bind more tightly to

Answer 27

Transition states

Question 28

Before induced fit occurs, the order of a reaction must undergo

Answer 28

The initial binding

Question 29

What is a cofactor?

Answer 29

A non-protein chemical compound bound to an enzyme to assist in catalysis

Question 30

What is a coenzyme?

Answer 30

A specific type of cofactor that carries chemical groups between enzymes

Question 31

What is a holoenzyme?

Answer 31

The complex of an enzyme that has its cofactor bound and is considered ‘complete’

Question 32

What has the effect of increasing the Vmax of a reaction upon binding to an enzyme?

Answer 32

An activator