Sean - Fates of Pyruvate

Question 1

How many different fates of pyruvate are there?

Answer 1

Seven

Question 2

What are the seven fates of pyruvate

Answer 2

Glycolysis

Fermentation

Lactate

Acetyl CoA

Oxaloacetate

Malate

Transamination

Gluconeogenesis

Question 3

Write about the fate of pyruvate in glycolysis
(7)

Answer 3

Pyruvate is created through glycolysis

2 molecules are produced for ever 1 molecule of glucose

Anaerobic

Occurs in cytoplasm of cells

In glycolysis -> PEP converted to pyruvate by pyruvate kinase which also facilitates transfer of P to ADP to create ADP

2 PEP are produced per 1 Glucose => 2 ATP

1 Glucose + 2 ATP = 4 ATP + 2 pyruvate

Question 4

Where does glycolysis take place?

Answer 4

Occurs in the cytoplasm of the cells

Question 5

Write a note on the fate of pyruvate in fermentation
(6)

Answer 5

The conversion of pyruvate to ethanol

Anaerobic fermentation

2 step process

Happens in yeast and microorganisms

NADH utilised via alcohol dehydrogenase is generated in 3rd step of glycolysis

Not possible in humans -> we lack the enzyme to convert pyruvate to acetaldehyde

Question 6

Write a note on the fate of pyruvate in lactate
(3)

Answer 6

Pyruvate is converted to lactate

Takes place when oxygen is limited

Produces low levels of energy

Question 7

What is lactate also called?

Answer 7

Lactic acid

Question 8

Write a note on the fate of pyruvate -> acetyl CoA
(3)

Answer 8

Pyruvate to acetyl CoA

Acetyl CoA has many fates e.g. fatty acid synthesis/ fed into citric acid cycle

Aerobic -> requires NAD which is a by product of aerobic ETC

Question 9

Write a note on the fate of pyruvate -> oxaloacetate

Answer 9

Pyruvate to oxaloacetate

Oxaloacetate can be converted into different amino acids

This is done when levels are low and energy requirements are high

Question 10

Write a note on the fate of pyruvate -> malate

Answer 10

Pyruvate converted into malate

Only done if malate is needed

Question 11

Write a note on the transamination fate of pyruvate

Answer 11

Pyruvate is converted into alanine

catalysed by alanine transferase

Depends on levels of amino acid present

Question 12

Write a note on the gluconeogenesis fate of pyruvate

Answer 12

Pyruvate converted to glucose via gluconeogenesis

Question 13

What is gluconeogenesis?
(2)

Answer 13

The production of new glucose

It is not the conversion of pyruvate back to glucose