Pyuvate oxidation & Kreb's cycle

Question 1

Pyruvate from glycolysis in the presence of oxygen

Answer 1

Pyurvate will enter the mitochondria and undergoes CAC & electron transport chain

Question 2

Pyruvate from glycolysis in the absence of oxygen

Answer 2

Pyruvate will undergoes fermentation (Lactic acid fermentation & alcohol fermentation)

Question 3

After glycolysis,pyruvate is transported into _______.

Answer 3

mitochondria matrix by MPC transport protein (Active transport)

Question 4

Pyruvate oxidation occurs in _______.

Answer 4

Mitochondria matrix

Question 5

Pyruvate oxidation overview

Answer 5

Pyruvate——->Acetyl CoA (Pyruvate dehydrogenase complex)

Question 6

Pyruvate dehydrogenase complex

Answer 6

1)Pyruvate dehydrogenase
2)Dihydrolipoyl transacetylase
3)Dihydrolipoyl dehydrogenase

Question 7

Pyruvate

Answer 7

CH3COCOO-

Pyruvic acid_CH3COCOOH

Question 8

Step of pyruvate oxidation

Answer 8

1)Decarboxylation {removal of CO2)
2)Dehydrogenation {removal of hydrogen)
3)Addition of CoA

Question 9

Acetyl CoA

Answer 9

CH3COSCoA

Question 10

Pyruvate oxidation contain removal of hydrogen but the hydrogen of pyruvate & acetyl Coa is same.Why?

Answer 10

The hydrogen can be from mitochondria matrix or from CoA not its own hydrogen.

Question 11

Do ATP gain from pyruvate oxidation?

Answer 11

No
Only NADH & CO2 is released from one pyruvate.

One glucose—–>2 Pyruvate—–>2 NADH+2CO2

Question 12

Products of pyruvate oxidation

Answer 12

2NADH+2CO2 per glucose
NADH+CO2 per pyruvate

Question 13

Acetyl CoA from pyruvate oxidation enters the _______.

Answer 13

Kreb’s cycle or citric acid cycle

Question 14

1st step of CAC

Answer 14

Acetyl CoA+Oxaloacetate——–>Citrate(Citrate synthase)

Question 15

2nd step of CAC

Answer 15

Citrate——–>Isocitrate(Aconitase)

*Remove H2 & Again add H2

Question 16

3rd step of CAC

Answer 16

Isocitrate——–>alpha keto glutarate+CO2(Isocitrate dehydrogenase+NADH)

*Oxidative dehydrogenation of isocitrate

Question 17

4th step of CAC

Answer 17

alpha keto glutarate+CoASH+NAD+———>Succinyl CoA+CO2(alphaketo dehydrogenase+NADH)

*Oxidative dehydrogenation of alpha keto glutarate

Question 18

5th step of CAC

Answer 18

Succinyl CoA+GDP——–>Succinate+CoA+GTP (Succinyl CoA synthetase)

*Release of GTP from GDP (GTP to ATP)

Question 19

6th step of CAC

Answer 19

Succinate+FAD——–>Fumarate+FADH2(Succinate dehydrogenase)

Question 20

7th step of CAC

Answer 20

Fumarate+H2O——–>Melate(Fumarase)

Question 21

8th step of CAC

Answer 21

Malate+NAH+——->Oxaloacetate+NADH (Melate dehydrogenase)

Question 22

There are ______ oxidation & ____ oxidative decarboxylation in CAC.

Answer 22

4 oxidation by dehydrogenase & 2 oxidative decarboxylation

*4 oxidation (3NADH & 1FADH2)
*2 oxidative decarboxylation (2CO2)

Question 23

How many steps in CAC?

Answer 23

8 steps

Question 24

Products of CAC per pyruvate

Answer 24

3NADH
1FADH2
1ATP (1GTP)
2CO2

Question 25

Products of CAC per glucose

Answer 25

6NADH 2FADH2 2ATP (2GTP) 4CO2

Question 26

Transport of pyruvate into mitochondrial matrix is _____.

Answer 26

Active transport (require ATP)

Question 27

All the enzymes of TCA are located in the mitochondral matrix.True or False?

Answer 27

False Except Succinate dehyrogenase is embedded in the inner mitochondrial membrane (Succinate--->Fumarate)