Catalysis

Question 1

What are the 6 classes of enzymes?

Answer 1

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

Question 2

What is the function of oxidoreductases? What is the class number?

Answer 2

Catalyze redox reactions. Class 1

Question 3

What is the function of transferases? What is the class number?

Answer 3

Catalyze group transfer reactions (phosphates, methyls). Class 2

Question 4

What is the function of hydrolases? What is the class number?

Answer 4

Catalyze hydrolysis reactions. Class 3

Question 5

What is the function of lyases? What is the class number?

Answer 5

Catalyze elimination reactions, bond cleavage. Class 4

Question 6

What is the function of isomerases? What is the class number?

Answer 6

Catalyze molecule rearrangement. Class 5

Question 7

What is the function of ligases? What is the class number?

Answer 7

Catalyze condensation reactions, bond formation. Class 6

Question 8

What does each number represent in the enzyme commission number?

Answer 8

First number is the class, second is the subclass, third is type within the subclass, fourth is the enzyme number

Question 9

Which class of enzymes catalyzes a reaction that uses NAD+ or another cofactor?

Answer 9

Oxidoreductases

Question 10

Which enzyme class is lactate dehydrogenase part of? What does it do?

Answer 10

Oxidoreductases. It oxidizes lactate into pyruvate

Question 11

Which enzyme class is alanine transamininase part of? What does it do?

Answer 11

Transferases. It moves an amine group from alanine to alpha-ketoglutarate

Question 12

Which enzyme class are kinases in?

Answer 12

Transferases

Question 13

Which enzyme class is pyrophosphatase part of? What does it do?

Answer 13

Hydrolases. It breaks a pyrophosphate into two phosphates

Question 14

Which enzyme class is pyruvate decarboxylase part of? What does it do?

Answer 14

Lyases. Breaks pyruvate into acetaldehyde and CO2

Question 15

What trait will be in the products of a reaction catalyzed by a lyase?

Answer 15

Double bond or a ring

Question 16

What is a lyase working in the opposite direction called?

Answer 16

Synthase

Question 17

Which enzyme class is alanine racemase part of? What does it do?

Answer 17

Isomerases. It changes the chirality of alanine

Question 18

Which enzyme class is glutamine synthetase part of? What does it do?

Answer 18

Ligases. It uses ATP and NH4+ to convert glutamate into glutamine

Question 19

Which class of enzymes always requires energy input?

Answer 19

Ligases

Question 20

Which enzyme class is most common?

Answer 20

Hydrolases

Question 21

Which enzyme class is the least common?

Answer 21

Ligases

Question 22

What will the enzyme commission number be for an enzyme with multiple catalytic domains?

Answer 22

Each domain has its own number

Question 23

How do enzymes lower the activation energy of a reaction?

Answer 23

The reaction mechanism is rerouted through multiple smaller steps