8. TCA, ETC and Oxidative Phosphorylation

Question 1

Is catabolism endergonic or exergonic?

Answer 1

Exergonic

Question 2

Summarise oxidation in terms of energy transfer

Answer 2

Loss of electrons, decrease in potential energy

Question 3

What are NAD and FAD abbreviated for?

Answer 3

Nicotinamide Adenine Dinucleotide

Flavin Adenine Dinucleotide

Question 4

What is the function of GLUT transporters?

Answer 4

Increase glucose flow into cells

Question 5

How does insulin indirectly increase glucose entry into cells?

Answer 5

Embeds GLUT transporters into cell membrane

Question 6

What happens to glucose once phosphorylated?

Answer 6

Trapped within cell

Question 7

What causes pyruvate dehydrogenase deficiency and when do symptoms appear?

Answer 7

Sex-linked disease
Lactic acidosis
Shortly after birth

Question 8

What are the symptoms of pyruvate dehydrogenase deficiency?

Answer 8

Nausea, vomiting, severe breathing problems, dysrhythmia

Question 9

How long do individuals with pyruvate dehydrogenase deficiency last?

Answer 9

Do not make it beyond childhood

Question 10

What other problems arise form pyruvate dehydrogenase deficiency?

Answer 10

Neurological problems, delayed development of mental and motor abilities

Question 11

Where does the Krebs cycle occur?

Answer 11

Mitochondrial matrix

Question 12

What does the series of reactions of the Kreb’s consist of?

Answer 12

Redox reactions

Question 13

How many decarboxylation reactions occur in the Kreb’s?

Answer 13

2

Question 14

What is the most important outcome of the Kreb’s?

Answer 14

Reduced NAD and FAD

Question 15

How many ATP molecules are produced and how?

Answer 15

1 from substrate level phosphorylation

Question 16

What 3 methods are the TCA cycle regulated by?

Answer 16

Allosteric inhibition
Substrate availability
Inhibition by product accumulation

Question 17

What is citrate synthase inhibited by?

Answer 17

Citrate and ATP

Question 18

What is isocitrate dehydrogenase inhibited by?

Answer 18

NADH and ATP

Question 19

What is a-KG dehydrogenase inhibited by?

Answer 19

NADH and Succinyl CoA

Question 20

What is pyruvate dehydrogenase inhibited by?

Answer 20

NADH and Acetyl CoA

Question 21

How does arsenic interfere with cellular longevity?

Answer 21

Allosteric inhibition of essential metabolic enzyme pyruvate dehydrogenase complex

Question 22

Where does the ETC take place?

Answer 22

Mitochondrial membrane

Question 23

What process moves electron through the chain?

Answer 23

Chemiosmosis

Question 24

What is the thermodynamics of electron transfer?

Answer 24

Exergonic

Question 25

What is the final electron acceptor of the ETC?

Answer 25

Oxygen, to form water

Question 26

How is H+ expelled from the mitochondrial matrix?

Answer 26

Proton pumps

Question 27

What is the result of H+ expulsion?

Answer 27

High potential energy in the cytosol forming an electrochemical gradient

Question 28

How is ATP produced in the ETC?

Answer 28

H+ flows back into MM, forcing ATP synthase to generate an ATP