Enzymes

Question 1

Active sites and denaturation

Answer 1

An enzymes is a protein molecule with an active site.
If the active site of an enzyme is altered in any way, it will not bind with the substrate and so will not be able to function.
The enzyme has been denatured.

Question 2

Active site

Answer 2

The area of an enzyme that the substrate binds on to.

Question 3

Substrate

Answer 3

The molecule that is affected by the action of an enzyme.

Question 4

Enzymes

Answer 4

They are biological catalysts. They speed up reactions in the human body.

Question 5

Collision theory

Answer 5

For the chemical reactions to occur, the reactants must collide with energy greater than or greater than or equal to the activation energy.

Question 6

Activation energy

Answer 6

The minimum energy required for collisions to break the bonds in the reactants and lead to a reaction.

Question 7

Four ways of increasing the rate of chemical reaction

Answer 7

1. Increasing the concentration of reactants
2. Increasing the surface area of a solid reactant
3. Increasing the temperature
4. Adding a catalyst
   Increasing the concentration and surface will mean that more frequent collisions will occur between reacting particles will have more energy and will move faster

Question 8

Factors that can affect enzyme activity

Temperature

Answer 8

Increasing the temperature increasing the rate of reaction due to increased average kinetic energy.
Increasing the temperature beyond the optimum temperature reduces the rate of reaction due to the breaking of bonds holding the enzymes tertiary structure in place. Then at the end there is no reaction because the enzyme is denatured.

Question 9

PH (factor)

Answer 9

For most enzyme - catalyzed, the enzyme can become denatured meaning:

1. The enzyme will permanently lose its shape.
2. The substrate will not be able to fit into the active site.
3. The enzyme can no longer catalyze the reaction.

Question 10

Concentration

Answer 10

If the substrate concentration is much greater than the enzyme concentration, then there will not be enough enzyme molecules for all the substrate to bind with the enzyme molecules in a given time. This will increase the rate of reaction.