Unit 5.1

Question 1

Coenzyme: NAD
name the group transferred

Answer 1

electrons (hydride ion)

Question 2

Coenzyme: FAD
name the group transferred

Answer 2

Electrons

Question 3

Coenzyme: heme in cytochromes
name the group transferred

Answer 3

electrons

Question 4

Coenzyme: Pyridoxal phosphate
name the group transferred

Answer 4

amino groups

Question 5

Coenzyme: Coenzyme A
name the group transferred

Answer 5

Acyl groups

Question 6

coenzyme: biotin, tetrahydrofolate, S-adenosylmethionine
name the group tranferred

Answer 6

One-carbon groups

Question 7

name the 4 types of catalytic strategies

Answer 7

1. general acid-base catalysis
2. covalent catalysis
3. metal ion catalysis
4. proximity and orientation

Question 8

turnover number

Answer 8

Kcat - the number of substrate molecules converted per enzyme molecule at saturation

Question 9

specificity constant

Answer 9

Kcat/Km - measures catalytic efficiency (rxn of free enzyme w/ substrate to product)

Question 10

Which of the following are inhibitors:
A. Lead
B. Statins
C. Aspirin
D. Penicillin
E. Ibuprofen
F. Methotrexate

Answer 10

All of them

Question 11

What type of inhibitor are the following:
A. Lead
B. Statins
C. Aspirin
D. Penicillin
E. Ibuprofen
F. Methotrexate

Answer 11

A. non-competitive
B. competitive
C. irreversible
D. irreversible
E. competitive
F. methotrexate

Question 12

Which of the following are major enzyme classes
A. Oxidoreductases
B. Transferases
C. Hydrolases
D. Lyases
E. Isomerases
F. Ligases
G. Proteases

Answer 12

A, B, C, D, E, F

Question 13

What do oxidoreductases do?

Answer 13

move electrons between molecules

Question 14

what do transferases do?

Answer 14

move chemical groups between molecules

Question 15

what do hydrolases do?

Answer 15

break bonds with water (e.g proteases)

Question 16

what do lyases do?

Answer 16

break bonds without water. add or remove atoms to or from a double bond

Question 17

what do isomerases do?

Answer 17

change molecular shapes by transferring groups within molecules

Question 18

what do ligases do?

Answer 18

create new bonds between molecules by condensation reactions
- ATP dependent

Question 19

what are the advantages of enzyme associations?

Answer 19

• enzymes are associated with metabolic coupling. this increases efficiency by channeling products between enzymes
• different configurations:
  1. enzyme aggregates
  2. assembly on scaffolds
  3. multi-domain multifunctional enzymes