TCA

Question 1

What are the three main functions of TCA

Answer 1

1. converts different fuels to one common fuel (NADH)
2. Serves as final meeting place for most oxidizable substrates
3. provides intermediates for biosynthesis

Question 2

Pyruvate Dehydrogenase

Answer 2

pyruvate–> hydroxyethyl-TTP + CO2
performs a condensation/decarboxylation reaction
TPP (thiamine)= prosthetic group

Question 3

Dihydrolipoyl transacetylase

Answer 3

hydroxyethyl-TTP –1–> acetyllipoamide + SH-CoA –2–> dihydrolipoamide + acetyl Co-A

1. oxidative transfer
   Lipoamide - prosthetic group
2. transacetylation

Question 4

dihydrolipoyl dehydrogenase

Answer 4

dihydrolipoamide + NAD+ –> Lipoamide +NADH
oxidation
FAD= posthetic group

Question 5

citrate synthase

Answer 5

condensation and hydrolysis of

OOA + Acetyl CoA –> citrate + CoA

Question 6

Aconitase

Answer 6

Dehydration and hydration
Citrate –> Isocitrate
facilitated by iron sulfur center

Question 7

Isocitrate dehydrogenase

Answer 7

oxidative decarboxylation

Isocitrate +NAD+ –> alpha-ketoglutarate + NADH + CO2

Question 8

alpha-ketoglutarate dehydrogenase complex

Answer 8

ox. decarboxylation
and formation of thioester
alpha-ketogulatarate + CoA + NAD+ –> Succinyl CoA +NADH + CO2

Question 9

Succinyl CoA synthase

Answer 9

Thioester cleavage and GTP synthesis (substrate evel phosphorylation)
Succinyl-CoA + ADP +Pi –> ATP+CoA+ succinate

Question 10

common intermediate principle

Answer 10

product of the first reaction is the substrate for the second reaction
ex. phosphohystidyl
Allows coupling of exergonic reaction to an endergonic reaction

Question 11

1. succinate dehydrogenase,
2. fumerase,
3. malate dehydrogenase

Answer 11

1. oxidation : this enzyme is bound to the inner membrane
2. hydration
3. oxidation