Metabolism IV Flashcards Preview

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Flashcards in Metabolism IV Deck (25):
1

What reaction does Pyruvate Carboxylase catalyze?

Converts Pyruvate to oxaloacetate in the mitochondria so that oxaloacetate can replenish the TCA cycle or be used in gluconeogenesis (p.101)

2

What reaction does Pyruvate Dehydrogenase catalyze?

Converts Pyruvate to Acetyl CoA in the mitochondria to transition from glycolysis to the TCA cycle (p.101)

3

What reaction does Lactic Acid Dehydrogenase (LDH) catalyze?

Converts Pyruvate to lactate in the cytosol via the cori cycle during anaerobic glycolysis (p.101)

4

What cofactor does Alanine aminotransferase require?

B6 (p.101)

5

What cofactor does Pyruvate Carboxylase require?

Biotin (p.101)

6

What cofactors does Pyruvate Dehydrogenase require?

B1, B2, B3, B5, lipoic acid (p.101)

7

What cofactor does Lactic Acid Dehydrogenase require?

B3 (p.101)

8

In what tissues is the Cori Cycle the major pathway of glycolysis?

RBCs, leukocytes, kidney medulla, lens, testes, cornea (p.101)

9

What are the products of the reaction Pyruvate --> Acetyl CoA?

1 NADH and 1 CO2 (p.101)

10

What enzyme catalyzes the reaction of Pyruvate to Acetyl CoA?

Pyruvate dehydrogenase (p.101)

11

What inhibits the enzyme pyruvate dehydrogenase?

ATP, Acetyl CoA, NADH (p.101)

12

What are the products of the Krebs Cycle?

3 NADH, 1FADH2, 2CO2, 1GTP per acetyl CoA = 10 ATP per Acetyl CoA

13

Where does the TCA cycle occur?

Mitochondria (p.101)

14

What cofactors are required by both the a-ketoglutarate dehydrogenase complex and the pyruvate dehydrogenase complex?

B1, B2, B3, B5, lipoic acid (p.101)

15

What is the starting substrate in the TCA cycle?

Citrate (p.101)

16

What is the 'end substrate' in the TCA cycle?

Oxaloacetate (p.101)

17

How do NADH electrons from glycolysis enter the mitochondria for use in the ETC?

Via the malate-aspartate or glycerol-3-phosphate shuttle (p.102)

18

What ETC complex are NADH electrons transferred to?

To complex I of the ETC (p.102)

19

What ETC complex are FADH2 electrons transferred to?

FADH2 electrons are transferred to complex II (at a lower energy level than NADH) (p.102)

20

How is ATP produced by the ETC?

Passage of electrons results in the formation of a proton gradient that is coupled to oxidative phosphorylation to drive ATP production (p.102)

21

What ETC complex is inhibited by Cyanide and CO?

Complex IV (p.102)

22

What ETC complex is inhibited by Oligomycin?

Complex V (p.102)

23

How much ATP is produced via ATP synthase in the ETC?

1 NADH --> 3 ATP; 1 FADH2 --> 2 ATP (p.102)

24

How do electron transport inhibitors poison the ETC?

Directly inhibit electron transport causing a decreased proton gradient and blocking ATP synthesis (p.102)

25

Name four electron transport inhibitors.

Rotenone, cyanide, antimycin A, CO (p.102)