Enzymes

Question 1

What are enzymes

Answer 1

protein based catalysts found in living things

highly specific - each enzyume optimised for one reaction

Question 2

How effective are enzymes?

Answer 2

• very
• speed up reaction 10¹⁰
• up to 500,000 molecules catalysted per second

Question 3

Describe the structure of an enzyme?

Answer 3

• usually globular protein
• has a cleft crevice in it , called the active site
  
  • where the reaction takes place
• the substrate is complex to the active site
  
  • this is the lock and key hypothesis

Question 4

How do enzymes work

Answer 4

• molecule fits precisely in active site and it held in just the right orientation to react
• it must temporarily bond by intermolecular forces
• these forces promote the movement of electrons within the substrate that lower the activation energy for the reaction

Question 5

What is stereospecificity?

Answer 5

• the active site of an enzyme can be so selective of a shape of a substrate that many enzymes only catalyse reaction of one o r other of a pair of enantiomers
• these are called stereoisomers
• the enzyme is said to be stereospecific

Question 6

How can enzymes be inhibited?

Answer 6

• change in temp
  
  • break weak bonds
• change in pH
  
  • effects hydrogen bonds

denature means have their shape changed

Question 7

How are enzymes deliberate inhibited?

Answer 7

• drugs cam be designed that effect their action
• molecules of a similar shape to its substrate needs to be divised
• this will block active site or bind to the enzyme itself and change the shape of the enzyme

Question 8

How are drugs desinged?

Answer 8

• computer modelling
• predict shapes before synthesis
• therefore predict properties