3.2 Factors Affecting Enzyme Action

Question 1

How does pH affect enzyme reactions

Answer 1

The shape of an enzyme comes from forces between the different parts of the protein molecule. These forces hold the folded chains in place.

A change in pH affects these forces, that’s why it changes the shape of the molecule. As a result the active site is lost the the enzyme can no longer act as a catalyst.

Different enzymes have different pH levels for which they work best, a change in pH can stop them working completely.

Question 2

Why is it so important to maintain your body temperature

Answer 2

Without enzymes none of the reactions in the body would happen fast enough to stay alive. This is why it is so dangerous for the body temperature to go to high. Once the body temperature reached 41C the enzymes start to denature death occurs shortly after.

Question 3

How does temperature affect the rate of enzyme reaction

Answer 3

Temperature affects the rate at which chemical reactions take place even when they’re controlled by biological catalysts

The rate of enzyme controlled reactions increases as the temperature increases.

This is only true up until a certain point. About 40c after this the protein structure of the enzyme is affected by the high temperature, the long amino acid chains begin to unravel. As a result the shape of the active site changes, it can no longer act as a catalyst because it cannot bond with the substrate.

So the rate of reaction drops rapidly. Most human enzymes work best at 37c