12.2 link reaction & krebs cycle Flashcards
1
Q
what is the purpose of link reaction?
A
active transport pyruvate into the matrix of mitochondria
2
Q
what are the reactants of the link reaction?
A
pyruvate + coenzyme A + NAD
3
Q
list the products of the link reaction & explain how they are formed.
A
acetyl coenzyme A + CO2 + reduced NAD
- pyruvate splits into CO2 + acetate + 2 H
- 2H accepted by NAD -> reduced NAD
- acetate combines with coenzyme A
4
Q
where does the krebs cycle occur?
A
matrix of mitochondria
5
Q
describe the krebs cycle. (3)
A
1) acetyl coenzyme A combines with 4C molecule -> 6C molecule & release coenzyme A
2) 6C molecule loses 2 CO2 & all H, reduced NAD & FAD by oxidation-reduction reactions
3) 1 ATP is formed by substrate-level phosphorylation
6
Q
what are coenzymes?
A
carry H atoms (H+ + e-)
7
Q
what does NAD do?
A
catalyse removal of dehydrogenase enzyme -> remove H atoms
