CAC

Question 1

Aconitase

Answer 1

Formation of isocitrate from citrate

Question 2

Isocitrate dehydrogenase

Answer 2

Catalyze a oxidative decarbox of isocitrate forming alpha ketoglutarate and nadh

Question 3

Citrate synthase

Answer 3

Catalyzes an irreversible reaction to condense ACOA and oxaloacetate to form citryl CoA and then citrate

Question 4

What are the two enzymes that regulate the CAC, and what regulates them?

Answer 4

isocitrate dehydrogenase; inhibited by ATP and NADH and activated by ADP; and alpha-ketoglutarate dehydrogenase complex; inhibited by ATP, succinyl CoA, and NADH

Question 5

What are anaplerotic reactions, and why are they relevant to the CAC?

Answer 5

Anaplerotic reactions are replenishing reactions, and it is important to replenish the CAC because it provides the precursors for biosynthesis

Question 6

What ist he major reaction which replenishes oxaloacetate?

Answer 6

pyruvate + CO2 +ATP +water–>oxaolacetate, adp, pi, and 2H+ with the use of pyruvate carboxylase

Question 7

What cycle exists in plants that does not in humans, and what purpose does it serve?

Answer 7

The glyoxylate cycle, and it can generate synthesis of carbohydrates from fats because it bypasses the two decarboxylation steps

Question 8

isocitrate lyase function

Answer 8

Splits isocitrate into succinate (to go to oxaloacetate and then to glucose) and glyoxylate

Question 9

Malate synthase function

Answer 9

Combines glyoxylate and acetyl CoA to generate malate

Question 10

After every CAC cycle, how many electrons NADHs, and FADH2s are produced?

Answer 10

8 electrons, 3 NADHs, and 1 FADH2