Citric Acid Cycle

Question 1

What is the Citric Acid Cycle

Answer 1

Common metabolic pathway for carbs, fatty acids, amino acids
Occurs in mitochondrial matrix
Very efficient

Question 2

What is the function of the Citric Acid Cycle (CAC)

Answer 2

Generates energy that’s passed on to electron transport chain
Does not produce ATP directly
O2 is not a reactant
Removes e-’s, passes them on to form NADH, FADH2
Produces 90% of aerobic cell energy

Question 3

Describe Acetyl CoA

Answer 3

Pyruvate and fatty acids oxidised to acetyl CoA in mitochondrial matrix
Allows different intermediates into main energy producing pathway of CAC

Question 4

What is the function of pyruvate dehydrogenase

Answer 4

Convert pyruvate to acetyl CoA

Question 5

Describe the CAC

Answer 5

Question 6

How is the CAC controlled

Answer 6

PyruvateDH controls entry in cycle by intermediate products
Checkpoint 1 - isocitrate dehydrogenase
Checkpoint 2 - α-ketoglutarate dehydrogenase
Allow for re-direction of cellular responses

Question 7

What reaction involve elctron carriers

Answer 7

1. Isocitrate to α-ketoglutarate
2. α-ketoglutarate to Succinyl-CoA
3. Succinate to Fumarate
4. Maltate to Oxaloacetate

(Succinyl-CoA to Succinate=GTP)

Question 8

What reaction in the CAC release CO2

Answer 8

Isocitrate to α-ketoglutarae
α-ketoglutarate to Succinyl-CoA

Question 9

Describe CAC links to other metabolic pathways

Answer 9