TCA cycle and electron transport chain

Question 1

What happens in the first stage of the TCA cycle?

Answer 1

Oxaloacetate is converted to citrate
By citrate synthetase
Addition of acetyl coA

Question 2

What happens in the second stage of the TCA cycle?

Answer 2

Citrate is converted to cis aconitate
By aconitase
H2O lost

Question 3

What happens in the third stage of the TCA cycle?

Answer 3

Cis aconitate is converted to isocitrate

By aconitase

Question 4

What happens in the fourth stage of the TCA cycle?

Answer 4

Isocitrate is converted to alpha-keto glutarate
By isocitrate dehydrogenase
CO2 is lost
NAD+ becomes NADH

Question 5

What happens in the fifth stage of the TCA cycle?

Answer 5

Alpha-keto glutarate is converted to succinyl coA
By alpha-keto glutarate dehydrogenase complex
CO2 is lost
NAD+ becomes NADH

Question 6

What happens in the sixth stage of the TCA cycle?

Answer 6

Succinyl coA is converted to succinate
By succinyl coA synthetase
GDP becomes GTP

Question 7

What happens in the seventh stage of the TCA cycle?

Answer 7

Succinate is converted to fumarate
By succinate dehydrogenase
FAD becomes FADH2

Question 8

What happens in the eighth stage of the TCA cycle?

Answer 8

Fumarate is converted to malate
By fumarase
Addition of H2O

Question 9

What happens in the ninth stage of the TCA cycle?

Answer 9

Malate is converted to oxaloacetate
By malate dehydrogenase
NAD+ becomes NADH

Question 10

What is the net yield of ATP per molecule of glucose?

Answer 10

36

Question 11

Where does the electron transport chain take place?

Answer 11

Inner mitochondrial membrane

Question 12

How many membrane bound complexes are involved in ETC?

Answer 12

4

Question 13

How many mobile e- carriers are involved in the ETC?

Answer 13

2
Coenzyme Q
Cytochrome C

Question 14

How many ATP does NADH yield?

Answer 14

3

Question 15

How many ATP does FADH2 yield?

Answer 15

2

Question 16

How is energy used to make ATP?

Answer 16

Energy from electron transport chain drives efflux of H+ from mitochondrial matrix
Proton electrochemical gradient is created
ATP synthesis by ATP synthase

Question 17

Where is pyruvate converted to acetyl coenzyme A?

Answer 17

In the mitochondrial matrix

Question 18

What converts pyruvate to acetyl coA?

Answer 18

Pyruvate dehydrogenase complex

Question 19

What is the pyruvate dehydrogenase complex?

Answer 19

5x10^6 Da
60 polypeptide chains
Three enzymes

Question 20

What is the equation for pyruvate to acetyl coA?

Answer 20

Pyruvate + coA + NAD+
to
Acetyl CoA + CO2 + NADH

Question 21

What is beriberi and what is its cause?

Answer 21

Weakness and fatigue
Vitamin B1 deficiency
B1 needed for PDHC