Enzymes

Question 1

What is catabolism?

Answer 1

Breaking down molecules to release energy

Question 2

What is anabolism?

Answer 2

Building up molecules that requires energy

Question 3

What is a common link between catabolism and anabolism?

Answer 3

ATP: coupled reactions

Question 4

What shuttles chemical energy between catabolism to anabolism?

Answer 4

ATP

Question 5

What is a coupled reaction?

Answer 5

One reaction provides energy for a second reaction that needs energy

Question 6

What is an endergonic reaction?

Answer 6

A reaction that requires energy

Question 7

What is an exergonic reaction?

Answer 7

A reaction that produces energy

Question 8

How are coupled reactions connected?

Answer 8

An intermediate

Question 9

What is a reduction?

Answer 9

When an atom gains electrons

Question 10

What is an oxidation?

Answer 10

When an atom loses electrons

Question 11

How is the function of an enzyme determined?

Answer 11

By its structure

Question 12

What do phosphatases do?

Answer 12

remove phosphate groups

Question 13

What do synthetases and synthases do?

Answer 13

Catalyze dehydration synthesis

Question 14

What do hydrolases do?

Answer 14

Promote hydrolysis

Question 15

What do dehydrogenases do?

Answer 15

Remove hydrogen atoms

Question 16

What do kinases do?

Answer 16

Add phosphate groups

Question 17

What do isomerases do?

Answer 17

Rearrange atoms

Question 18

What 5 things is enzyme activity controlled by?

Answer 18

Temperature
pH
conc of cofactors and coenzymes
Conc of enzyme and substrate
Stimulatory or inhibitory effects of products on enzyme function

Question 19

What is the pH optimum?

Answer 19

narrow pH range that an enzyme exhibits peak activity
Reflects the pH of the fluid the enzyme is found in

Question 20

How does change from optimum pH impact enzymes?

Answer 20

Conformational changes, denatures

Question 21

How does temperature impact enzyme rate?

Answer 21

Increase rate until temperature reaches a few degrees above body temperature, then enzyme denatures

Question 22

What are coenzymes made of?

Answer 22

Organic molecules derived from water-soluble vitamins

Question 23

What do coenzymes do?

Answer 23

Transport H atoms and other small molecules between enzymes

Question 24

What are cofactors?

Answer 24

Metal ions that aid enzymes

Question 25

What are 5 examples of cofactors?

Answer 25

Ca2+ Mg2+ Mn2+ Cu2+ Zn2+

Question 26

What 2 mechanisms do cofactors perform?

Answer 26

Helps form the active site Help enzyme-substrate binding

Question 27

What is a zymogen?

Answer 27

An inactive form of an enzyme that is activated when needed

Question 28

What is the law of mass action?

Answer 28

A single enzyme can drive a reaction in two opposite directions, depending on the concentration of the reactants and products

Question 29

Are most metabolic pathways branched or linear?

Answer 29

Branched

Question 30

What is a branched metabolic pathway?

Answer 30

Several products can be produced

Question 31

What is a competitive inhibitor?

Answer 31

Substrate and inhibitor compete for active site

Question 32

What is a noncompetitive inhibitor?

Answer 32

Inhibitor binds to allosteric site

Question 33

What is an allosteric site?

Answer 33

Where enzymes bind to alter the shape of the active site

Question 34

How can branch points of a metabolic pathway be inhibited?

Answer 34

Negative feedback, s final product inhibits branch point

Question 35

What are 3 outcomes of mutation of an enzyme in a pathway?

Answer 35

1. Loss of important product 2. Accumulation of intermediary products 3. Too many alternative products from a different branch