Regulation of Protein Activity

Question 1

How are enzymes regulated in the long term?

Answer 1

Altering the rate of protein degradation and synthesis

Question 2

Why do allosteric enzymes show a sigmoidal relationship?

Answer 2

As a substrate binds to a subunit of an enzyme, binding to the other units becomes easier.

Question 3

How do allosteric activators increase the rate of reaction?

Answer 3

They increase the number of enzymes in the R state

Question 4

Enzymes can be regulated by covalent modification. Describe this process

Answer 4

Protein kinase transfers a phosphate from ATP to the OH group of Ser, Thr and Tyr.

Question 5

Many enzymes are activated by proteolytic cleavage. Describe this process

Answer 5

Enzymes are made as inactive zymogens. The zymogen is cleaved after a specific signal to activate the enzymes

Question 6

Give 2 general ways of regulating enzymes in the short term

Answer 6

Changing the enzyme conformation

Controlling concentrations of substrates, products and inhibitors