12.2 link reaction and krebs cycle

Question 1

write the equation for the link reaction

Answer 1

pyruvate + NAD + CoA -> acetyl CoA + reduced NAD and CO2

Question 2

where does the link reaction occur?

Answer 2

matrix of mitochondria

Question 3

where does the Krebs cycle occur?

Answer 3

matrix of mitochondria

Question 4

what happens in the link reaction?

Answer 4

• pyruvate -> acetate + Co2
• 2 hydrogens forms reduced NAD
• acetate + CoA -> acetyl CoA

Question 5

what happens in the Krebs cycle?

Answer 5

• acetyl CoA + 4 C -> 6 C
• 2 CO2 released and 1 ATP
• FAD and NAD are reduced
• 4 C produced again ready to combine with another acetyl CoA

Question 6

which coenzyme(s) is/are used in photosynthesis?

Answer 6

NADP

Question 7

which coenzyme(s) is/ are used in respiration?

Answer 7

FAD and NAD

Question 8

which coenzyme is only used in Krebs?

Answer 8

FAD

Question 9

4 reasons why Krebs form an important role in the cells

Answer 9

• breaks down macromolecules
• produces hydrogen atoms for ETC for ATP production
• regenerates 4C that combines with acetyl CoA which would otherwise accumulate
• source of intermediate compounds used for manufacture of fatty acids, amino acids and chlorophyll