Chap 5- enzymes Flashcards
1
Q
Why are enzymes important?
A
- Speed up biochemical reactions
- High reaction speed necessary to sustain life
2
Q
How does an enzyme work?
A
- Enzyme has a complementary shape to substrate
- Substrate molecules bind
- Enzyme-substrate complex formed at active site
- Complementary shape of active allows specificity
- Product is produced
- Each enzyme is specific for one shape of substrate
- One reaction occurs each time substrate binds
3
Q
How does increasing temperature affect enzymes?
A
- Up to optimum temperature: enzyme activity increases with increasing temperature
- Enzyme and substrate have more kinetic energy
- More likely to bind to active site due to more effective collisions
- Over optimum temperature: enzyme activity decreases with increasing temperature
- Over optimum temperature enzyme loses shape - denatured
- Denatured enzyme cannot bind substrate
4
Q
How does a change in pH affect enzymes?
A
- Activity highest at optimum pH
- Above or below optimum, activity decreases
- Changes in pH alter the 3D shape
- If the 3D shape changes, the enzyme is denatured and cannot fit the substrate
