Lecture 6: Key Summary Points

Question 1

TCA CYCLE key points

Answer 1

TCA Cycle = 1 ATP, 3 NADH, 1 FADH2

Question 2

PDH complex is…

Answer 2

Activated by: AMP, CoA, NAD+, Ca+

Inhibited by: ATP, acetyl-CoA, NADH, fatty acids

Question 3

Citrate synthase is…

Answer 3

Activated by: ADP

Inhibited by: NADH, acetyl-CoA, citrate, ATP

Question 4

IDH is…

Answer 4

Activated by: Ca2+, ADP

Inhibited by: ATP

Question 5

Alpha-KGDH complex is…

Answer 5

Activated by: Ca2+

Inhibited by: Succinyl-CoA, NADH

Question 6

Which is the only reversible enzyme that is also regulated?

Answer 6

Succinate dehydrogenase

Question 7

What do fatty acids inhibit?

Answer 7

E2 in PDH

Question 8

What direct effect does Ca2+ or Mg2- have on phosphatase?

Answer 8

It will activate it

Question 9

What direct effect does NADH or acetyl-CoA have on kinase?

Answer 9

It will activate it

Question 10

Which cofactor does Hg2+ bind to?

Answer 10

Lipoic acid of E2 of PDH

Question 11

When IDH is inhibited, what will accumulate?

Answer 11

Citrate

Question 12

What is the fate of citrate

Answer 12

Citrate will be moved from mitochondria to cytoplasm where citrate lyase will degrade citrate to acetyl-CoA and oxaloacetate

Question 13

Isocitrate dehydrogenase is activated by what?

Answer 13

Isocitrate
Oxaloacetate
Pyruvate
3-phosphoglycerate
Phosphoenolpyruvate

Question 14

Why are we regulating the TCA cycle as so many enzymes?

Answer 14

Because the TCA cycle consists of anaplerotic pathways

Question 15

What are the four ways to biosynthesize oxaloacetate?

Answer 15

1. Pyruvate carboxylase
2. PEPCK
3. PEP carboxylase
4. MDH