Enzymes

Question 1

What is an enzyme

Answer 1

An enzyme speeds up the rate of a chemical reaction and enables metabolic reactions to occur without being used up

They do this by lowering the activation energy through forming enzyme substrate complexes

Question 2

Describe the induced fit model

Answer 2

Substrate enters enzymes active site and is not yet complimentary

Binding of the substrate molecule induces the change in the shape of the active site, so it is now complimentary to the substrate.

As the active site changes shape it causes distortion in the substrate

When the substrate leaves the active site the active site then returns to its previous state

Question 3

Effect of temperature on enzymes

Answer 3

As the temperature increases the molecules have more kinetic energy so there are more successful collisions and therefore an increased rate of reaction

However above the optimum temperature high kinetic energy causes amino acids in polypeptide chain to be broken

This breaks hydrogen and ionic bonds between the R groups, the tertiary structure is therefore lost