Metabolism and its Control 1

Question 1

What is ATP made of

Answer 1

• ribose
• adenine
• triphosphate

Question 2

What are the two main glucose types

Answer 2

Haworth Projection

Fischer Projection

Question 3

What is the overall yield of glycolysis

Answer 3

2X Pyruvate
2 ATP
2 NADH

Question 4

Where does glycolysis take place

Answer 4

In the cytosol

Question 5

What are the main stages of glycolysis

Answer 5

1) glucose is primed with two phosphorylation steps
2) one isomseration to form F-1,6-bp
3) this molecule splits to give GA-3-P
4) This molecules Is converted to pyruvate

Question 6

3 steps in glycolysis

Answer 6

Priming stage
Splitting stage
Oxidoreduction- phosphorylation stage

Question 7

What happens to pyruvate after glycolysis

Answer 7

It enters the TCA cycle

Or enter anaerobic respiration

Question 8

What is gluconeogenesis

Answer 8

The reverse of glycolysis

Question 9

What substances is Acetly CoA formed from

Answer 9

• amino acid
• Pyruvate
• fatty acid (reversible process)

Question 10

What is the role of the PHD complex

Answer 10

PHD complex ( pyruvate dehydrogenase) removes carbon dioxide and a H+ ion to from NADH and acetyl CoA which binds to coenzyme A.
This takes place in the matrix of the mitochondria

Question 11

What is the cori cycle

Answer 11

When lactate is produced, the liver uses lactate to make glucose by gluconeogenesis for the glycolysis stage

Question 12

What are the irreversible enzymes in glycolysis

Answer 12

Hexokinase
Phosphofructokinase
Pyruvate kinase

Question 13

How does fatty acid contribute to metabolism

Answer 13

Fatty acids can be converted into acetyl CoA by beta oxidation

Question 14

What are the irreversible enzymes in gluconeogenesis

Answer 14

Pyruvate carboxylase
Fructose 1,6 bisphosphatase
Glucose 6-phosphatase

Question 15

What complications may occur in the glycolysis stage

Answer 15

Arsenic poisoning- this means that ATP generation is skipped

Question 16

Describe the details of the glycolysis stage

Answer 16

Priming stage- energy investment
Glucose > glucose 6 phosphate > fructose 6 phosphate> fructose 1,6 bisphosphate.

Splitting stage- remember that fructose 1,6 bisphosphate splits into two products
Fructose 1,6 bisphosphate > dihydroxyacetone (DHAP) + glyceraldehyde-3-phosphate (GAP). GAP is the molecule we want.
DHAP is converted to GAP by triosphosphate isomerise

Oxidoreduction-phosphorylation stage- energy generation
GAP> 1,3-Bisphoglycerate> 3 phosphoglycerate> 2 phosphoglycerate> phosphoenolpyruvate> pyruvate.

Question 17

How is the PHD complex regulated

Answer 17

The PHD complex is activated by phosphatase enzyme when it removes a phosphate group
The PHD complex is inactivated when kinase enzyme add a phosphate group to it

Question 18

How is the kinase enzyme that inactivates the PHD complex regulated?

Answer 18

• Pyruvate blocks kinase activity so PHD complex is not inactivated
• Acetyl CoA activates the kinase enzyme to inactivate the PHD complex

Question 19

Which two steps in glycolysis create ATP

Answer 19

• Conversion of 1,3 bisphospholycerate to 3, phosphoglcerate

- phosphoenolpyruvate to pyruvate

Question 20

Which two steps in glycolysis use ATP

Answer 20

• glucose to glucose-6 phosphate

- fructose 6 phosphate to fructose 1,6 bisphosphate

Question 21

What are the products of anaerobic respiration

Answer 21

Lactate only

Question 22

Where does beta oxidation of fatty acids to make Pyruvate occur

Answer 22

In the mitochondrial matrix

Question 23

Is the link reaction of marketing acetly CoA with Pyruvate dehydrogenase reversible or irreversible

Answer 23

Irreversible