Enzymes Flashcards
1
Q
Define the term ‘biological catalyst’.
A
Enzymes that increase the rate of metabolic reactions in cells and organisms.
2
Q
What are the benefits of enzymes?
A
- They lower the activation energy needed for a reaction to begin
- They lower the temperature needed to produce the same amount of products
- They speed up the rate of reaction.
3
Q
What is the Lock and Key Hypothesis?
A
- The idea that a substrate with a complementary shape can bind with an enzyme’s active site.
- The enzyme holds the substrate in place so the reaction can happen more easily
- Each enzyme can only catalyse one specific reaction
4
Q
What is the Induced Fit Theory?
A
- The idea that the substrate does not have to be the exact shape of the enzyme’s active site to bind to it.
- The enzyme’s active site is slightly flexible and can change shape slightly to fit more closely around the substrate.
5
Q
How does increasing enzyme concentration increase the rate of reaction?
A
- The more enzymes in a solution, the more active sites present.
- Therefore, the substrate molecules are more likely to collide with an active site and form the enzyme-substrate complex.
6
Q
How does substrate concentration become a limiting factor as enzyme concentration increases?
A
- Eventually substrate in solution will be used up.
- Therefore, adding increasing enzyme concentration will not increase the rate of reaction because there is no substrate to create the enzyme-substrate complex.
7
Q
How does increasing substrate concentration increase the rate of reaction?
A
- More substrate increases the frequency of collisions between active sites and substrate.
8
Q
How does enzyme concentration become a limiting factor as substrate concentration increases?
A
- The reaction will reach a saturation point which means that all active sites will become full so rate of reaction will not increase as all enzymes are being used.
