2.5 Enzymes

Question 1

What is an enzyme?

Answer 1

A biological catalyst that lowers the energy needed for a chemical reaction.

Question 2

What type of proteins are enzymes?

Answer 2

globular proteins

Question 3

Why are enzymes usually immobilised?

Answer 3

allows:
 concentration to be higher
to be reused 
become resistant to denaturation 
products are not contaminated 
catalyst can be controlled

Question 4

How do you get lactose free milk?

Answer 4

add lactase

Question 5

What are advantages to lactose free milk? q

Answer 5

Lactose intolerant people can have it
sweeter so no need to add sugar
smoother ice cream, lactose is crystallised
glucose and galactose ferment faster - quicker yogurt and cheese.

Question 6

What factors affect enzyme activity?

Answer 6

Temperature, pH, concentration of substrate

Question 7

How does temperature affect enzyme activity?

Answer 7

enzyme activity increases when temperature goes up, however when reaches a really high temperature it denatures.

Question 8

How does pH affect enzyme activity?

Answer 8

enzyme activity reduces when pH reduces or increase from optimum pH. optimum is 7.

Question 9

How does substrate concentration affect enzyme activity?

Answer 9

enzyme activity increases when concentration increases - more collisions.