2.5 Enzymes Flashcards
What is an enzyme?
A globular protein that acts as biological catalyst by speeding up the rate of a chemical reaction
What happens to enzymes when they catalyse a reaction?
They are not changed or consumed by the reaction
Can enzymes be reused?
Yes
What are enzymes typically named after?
The molecules they react with
What is the active site?
The region on the surface of the enzyme which binds to the substrate molecule
What are the two ways the active site and substrate complement each other?
Shape and chemical properties
What is capable of binding to a particular enzymes active site?
A specific substrate
Where do enzyme reactions typically take place?
In aqueous solution
What does the fact that enzyme reactions take place in aqueous solutions show about its position?
The substrate and the enzyme are randomly moving within the solution
What does an enzyme being in a fixed position do?
Serves to localise reactions to particular sites
What does enzyme catalysis need?
The substrate to be in close proximity with the active site
When is an enzyme-substrate complex formed?
When a substrate binds to the enzymes active site
How is an enzyme product complex created?
When the enzyme catalyses the conversion of the substrate into product
What happens after the enzyme product complex is created?
The enzyme and product dissociate
How can you increase the rate of enzyme catalysis?
By increasing the frequency of collisions
How can you increase the rate of collisions?
Increasing the molecular motion of the particles
Increasing the concentration of the particles
What are the shape and chemical properties of an active site dependent on?
The tertiary structure of the enzyme
What can cause an enzyme structure to be modified?
External factors like temperature and pH
How does temperature and pH affect enzymes?
They disrupt the chemical bonds which maintains the structure of the enzyme causing denaturation
What will a change to the structure of the active site do?
Negatively affect the enzymes capacity to bind to the substrate
What affects the rate of activity of an enzyme?
Temperature
pH
Substrate concentration
What does low temperature during a reaction result in?
Insufficient thermal energy for the enzyme catalysed reaction to happen