Enzymes

Question 1

Enzymes

Answer 1

biological catalysts, primarily proteins, that significantly accelerate biochemical reactions without being consumed in the process

Question 2

Reaction Velocity

Answer 2

the rate at which a reaction proceeds

Question 3

Michaelis-Menten Kinetics

Answer 3

a widely used model to describe the kinetic behavior of many enzymes

Question 4

Michaelis Constant (Km)

Answer 4

the substrate concentration at which the reaction velocity is half its maximum

Question 5

Velocity Maximum (Vmax)

Answer 5

the maximum rate of the reaction when the enzyme is fully saturated with substrate

Question 6

Competitive inhibition

Answer 6

the inhibitor competes with the substrate for binding to the active site

Question 7

uncompetitive inhibition

Answer 7

the inhibitor binds only to the enzyme-substrate complex

Question 7

noncompetitive inhibition

Answer 7

the inhibitor binds to a site other than the active site, affecting the enzymes conformation and activity

Question 8

irreversible inhibition

Answer 8

the inhibitor forms a covalent bond with the enzyme, permanently inactivating it

Question 9

Allosteric enzymes

Answer 9

enzymes that do not follow Michaelis-Menten kinetics and have multiple active sites and cooperative binding

Question 10

active site

Answer 10

a specific region on the enzyme where the substrate bonds and catalysis occurs

Question 11

cofactor

Answer 11

non-protein molecules required for the activity of some enzymes

Question 12

coenzyme

Answer 12

organic cofactors, often derived from vitamins

Question 13

prosthetic group

Answer 13

tightly bound coenzymes that are permanently associated with the enzyme

Question 14

holoenzyme

Answer 14

an enzyme with its required cofactor

Question 15

apoenzyme

Answer 15

an enzyme without its cofactor

Question 16

transition state

Answer 16

a high-energy unstable intermediate state that a reaction must pass through to form products

Question 17

Activation energy (DG)

Answer 17

the minimum amount of energy required to start a chemical reaction

Question 18

Turnover Number (kcat)

Answer 18

represents the number of substrate molecules converted to product per second

Question 19

specificity constant (kcat/Km)

Answer 19

a measure of catalytic efficiency, reflecting both the enzyme’s affinity for the substrate and its turnover rate

Question 20

Inborn metabolic errors

Answer 20

genetic disorders caused by enzyme deficiencies, leading to the accumulation or deficiency of specific metabolites

Question 21

carbonic anhydrase

Answer 21

catalyses the reversible hydration of carbon dioxide

Question 22

proteolytic enzymes

Answer 22

break down proteins by hydrolyzing peptide bonds

Question 23

aspartate aminotransferase

Answer 23

catalyzes the transfer of an amino group from aspartate to alpha-ketoglytarate

Question 24

glycopeptide transpeptidase

Answer 24

involved in bacterial cell wall synthesis and is the target of penicillin antibiotics

Question 25

proline racemase

Answer 25

catalyzes the interconversion of L-proline and D-proline

Question 26

sequential reactions

Answer 26

characterized by the formation of a ternary complex consisting of the enzyme and both substrates

Question 27

double-displacement reactions

Answer 27

characterize by the formation of a substituted enzyme intermediate

Question 28

reversible inhibition

Answer 28

characterized by a rapid dissociation of the enzyme-inhibitor complex