Exam 4

Question 1

Ways enzyme increase reaction rate

Answer 1

Lower activation energy by stabilizing the transition state
Provide alternate path for product formation
Reduce entropy by orienting substrate’s appropriately for reaction to occur

Question 2

Cofactor

Answer 2

Small, does not contain carbon
Aids in catalytic mechanisms at active site
Provides additional groups to supplement active site
-metal ions

Question 3

Coenzyme

Answer 3

Larger, contain carbon
Vitamins
Some are proesthetic-> bind so strong it is permanently associated

Question 4

Holoenzyme

Answer 4

Enzyme with cofactor/ coenzyme
(Whole)

Question 5

Apoenzyme

Answer 5

Enzyme without cofactor/ coenzyme

Question 6

Oxireductase

Answer 6

Redox reactions ex: dehydrogenase

Question 7

Transferase

Answer 7

Transfer functional groups
Ec: kinase

Question 8

Hydrolase

Answer 8

Use H2O to break bond
Ex: lipase

Question 9

Lyase

Answer 9

Cleave without H2O
Ex:carboxylase

Question 10

Isomerase

Answer 10

Rearrange intermolecular, make isomer
Ex: mutase

Question 11

Ligase

Answer 11

Form bonds using ATP
Ex: Synthetase

Question 12

Active site

Answer 12

Contains binding site (bind and orient) and catalytic site (reduce chemical activity)

Question 13

Reversible mechanism

Answer 13

Noncovalent binding

Question 14

Irreversible

Answer 14

Inhibitory molecule forms covalent bind with catalytic groups in active site

Question 15

Competitive

Answer 15

Binds to enzyme
Increase Km
Decrease Vmax

Question 16

Uncompetitive

Answer 16

Bind to ES
Decrease Km
Decrease Vmax

Question 17

Pure noncompetitive

Answer 17

E= Es
No change Km
Decrease Vmax

Question 18

Mixed noncompetitive

Answer 18

E does not equal ES
Increase or decrease Km
Decrease Vmax

Question 19

Mixed noncompetitive with increase Km

Answer 19

Prefers E
Shift right

Question 20

Mixed noncompetitive with decreased Km

Answer 20

Prefers ES
Shifts left

Question 21

Kinase

Answer 21

Phosphorylate Ser, Thr, and Tyr b/c have OH that can be manipulated
Can activate or inhibit enzyme activity

Question 22

Zymogen

Answer 22

Inactive precursor protein
Becomes active upon cleavage
Precursor protein called pro protein or proenzyme

Question 23

Endocrine

Answer 23

Acts on cells far from site of release

Question 24

Paracrine

Answer 24

Acts of cells locally

Question 25

Autochrome

Answer 25

Acts on cell that released it