MB - Enzyme Strategies and Proteases

Question 1

What are the 2 types of enzyme kinetic mechanisms?

Answer 1

1. Sequential
2. Ping-pong

Question 2

What is the difference between the 2 kinetics mechanisms?

Answer 2

• Sequential involves the binding and catalysis of multiple substrates at the same time
• Ping-pong involves the binding and catalysis of one substrate at a time

Question 3

What are the 4 general enzyme strategies?

Answer 3

1. Position the reactants correctly for interaction
2. Distort the reactants making them less stable
3. Stabiliste the transition state
4. Change the environment to favour the reaction

Question 4

What happens when theres no enzyme present?

Answer 4

Substrate molecules arrive from all angles and so are unlikely to bind

Question 5

What does the addition of an enzyme help with?

Answer 5

• Substrate molecules can only bind from one direction and hence are more likely to attatch
• Enzymes also destabilise the substrate and stabilise the transition state

Question 6

What are the 3 Specific Chemical Strategies?

Answer 6

1. Covalent catalysis
2. Acid/base catalysis
3. Metal ion catalysis

Question 7

What is proteolysis?

Answer 7

Where peptide bonds are cleaved by boiling in 6M HCl acid for 24 hours

Question 8

What are serine proteases?

Answer 8

Enzymes that cleave peptide bonds, in which serine acts as the nucleophilic amino acid