Lecture 20

Question 1

has reactive thiol group

Answer 1

coenzyme a

Question 2

catalyzes an oxidative carboxylation

Answer 2

PDH complex

Question 3

irreversible oxidation process in which the carboxyl grouip is removed forming CO2

Answer 3

oxidative carboxylation

Question 4

coenzyme with two thiol groups that can undergo reversible oxidation to a disulfide bond

Answer 4

lipoate

Question 5

3 PDH complex enzymes

Answer 5

pyruvate dehydrogenase, dihydrolipoyl transacetylase, dihydrolipoyl dehydrogenase

Question 6

E1 enzyme

Answer 6

pyruvate dehydrogenase

Question 7

E2 enzyme

Answer 7

dihydrolipoyl transacetylase

Question 8

E3 enzyme

Answer 8

dihydrolipoyl dehydrogenase

Question 9

step 1 oxidative decarboxylation of pyruvate

Answer 9

decarboxylation of pyruvate to hydroethyl derivate

Question 10

step 2 oxidative decarboxylation of pyruvate

Answer 10

oxidation of hydroethyl derivate to acetyl group

Question 11

step 3 oxidative edecarbozylation of pyruvate

Answer 11

esterification of acetyl to a lipoyl -SH group, followed by transesterification to CoA to form acetyl CoA

Question 12

step 4 oxidative decarboxylation

Answer 12

electron transfer to regen oxidized form of lipoyllsyl group

Question 13

step 5 oxidative decarboxylation

Answer 13

electron transfer to regenerate oxidized FAD, forming NADH

Question 14

passage of intermediates from one enzyme directly to another without release

Answer 14

substrate channeling

Question 15

5 cofactors of PDH complex

Answer 15

TPP, lipoate, CoA, FAD, NAD+