Metabolic pathways and ATP production II

Question 1

Draw the krebs cycle

Answer 1

add pic

Question 2

What are the products of the TCA cycle

Answer 2

Each turn of the cycle produces two molecules of CO2 (waste) plus three molecules of NADH, one molecule of GTP and one molecule of FADH2.

Question 3

What are the names of the 8 molecules in the krebs cycle.

Answer 3

Oxaloacetate (4C)

Citrate (6C)

Isocitrate (6C)

alpha-ketogluterate (5C)

succinyl-CoA (4C)

Succinate (4C)

Fumerate (4C)

Malate(4C)

Question 4

Where is succinate dehydrogenase located?

Answer 4

It is firmly attached to the inner surface of the inner mitochondrial membrane. Here, it can communicate directly with components in the respiratory chain, as we shall see in the next lecture.

Question 5

How many molecules of ATP is generated in the krebs cycle?

For 1 cycle.

Three ATP molecules are formed by the re-oxidation of each NADH molecule.

Two ATP molecules are formed by the re-oxidation of each FADH2 molecule.

Answer 5

12

from the Krebs Cycle:

Oxidation of 1 X acetyl CoA molecule gives 3 x NADH + 1 x FADH2 + 1x GTP = 12 ATP

Question 6

How are amino acids converted into products that can enter the krebs cycle?

Answer 6

Remove the amino group from the amino acid. Transamination- The amino froup is transferred from an amino acid to a keto acid froming new pairs of amino acids and keto acids add pic

Question 7

How does NADH, or more accurately, its high-energy electrons, cross from the cytosol into the matrix of the mitochondria ?

Answer 7

The Glycerol Phosphate Shuttle – skeletal muscle, brain The Malate-Aspartate Shuttle - liver, kidney and heart

Question 8

In what organs is the The Glycerol Phosphate Shuttle found?

Answer 8

skeletal muscle, brain

Question 9

In what organs is the The Malate-Aspartate Shuttle found?

Answer 9

liver, kidney and heart

Question 10

State what happens during the Glycerol Phosphate shuttle?

Answer 10

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Question 11

State what happens during Malate-Aspartate Shuttle?

Answer 11

A hydride ion (H-) is transferred from cytoplasmic NADH to oxaloacetate to give malate, a reaction catalysed by cytosolic malate dehydrogenase (MDH). Malate can be transported into the mitochondria where it is rapidly re-oxidised by NAD+ to give oxaloacetate and NADH (catalysed by mitochondrial MDH). add pic

Question 12

What is the net reaction for NADH in the Malate-Aspartate shuttle?

Answer 12

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Question 13

What is the difference between NADPH and NADH?

Answer 13

NADPH takes part in anabolic reactions, whereas NADH takes place in catabolic reactions.