How enzymes work

Question 1

reaction free energy equations

Answer 1

ΔH - TΔS = -RTlnKeq

Question 2

Limit to enzyme catalysis rates

Answer 2

Physics f diffusion, molecules cannot interact any faster, can’t expect enzymes to work with no substrate bound.

Question 3

Cofactors

Answer 3

Metal ions and coenzymes

Question 4

Apo- vs Holo-

Answer 4

apo- without cofactor
holo- with factor

Question 5

Coenzymes

Answer 5

organic molecules such as cosubstrates (weak bond) and prosthetic groups (tight bond)

Question 6

Acid-base catalysis

Answer 6

transfer or removal of H+

Question 7

Covalent catalysis

Answer 7

Transient formation of covalent bonds between the enzyme and substrate

Question 8

metal catalysis

Answer 8

Direct or indirect role often in Redox rxns

Question 9

chymotrypsin

Answer 9

Uses covalent and acid-base catalysis to hydrolyse a peptide bond.

Question 10

Catalytic triad of chymotrypsin

Answer 10

hydrolysis of the N - C bond
Asp - stabilises
His - acts as an acid or base
Ser - nuc. attack