Metabolic Regulation

Question 1

Why is metabolic regulation required ?

Answer 1

1. Prevents waste of energy
2. Maintains homeostasis
3. To store energy and release it when required

Question 2

How is metabolism controlled ?

Answer 2

1. Levels and accessibility of substrates
2. Amounts of metabolic enzymes
3. Modulation of catalytic activities of enzymes

Question 3

What is enzyme turnover determined by ?

Answer 3

1. Alteration of transcription factor by external signals
2. Stability of mRNA species
3. Rate of translation
4. Rate of protein degradation

Question 4

What is allosteric regulation?

Answer 4

The control of an enzymes activity by binding of a regulatory molecule at a site that is not the active site.
This causes a conformational change which either increases or decreases enzyme activity.

Question 5

What is adenylate control ?

Answer 5

How the energy status of the cell regulates metabolic pathways

Question 6

Describe the range of energy change

Answer 6

0 (all AMP)
1 (all ATP)

Question 7

Name an ATP-generating pathway

Answer 7

Glycolysis

Question 8

Name an ATP-utilising pathway

Answer 8

Lipogenesis

Question 9

What is covalent modification?

Answer 9

A way to regulate enzyme activity by chemically adding or removing functional groups to the enzyme by reversible covalent bonds

Question 10

What are the common types of covalent modification?

Answer 10

1. Phosphorylation- changes enzyme shape and activity
2. Acetylation- can regulate gene expression or enzyme activity
3. Methylation- can affect protein-protein interactions