Investigate how varying PH affects the activity of the peroxidase enzyme.

The peroxides investigation.

Introduction

Peroxides is the incorrect name for this enzyme the correct term is catalase. It catalyses the breakdown of hydrogen peroxide. It is present in all body cells especially LIVER cells which are very active.

catalase

Hydrogen peroxide water + oxygen

catalase

2h2O2 2h2O+O2

Enzymes are biological catalysts and a catalyst is a substance that speeds up the rate of reaction during the reaction it gets changed e.g. If we did not have enzymes we would die because we would not be able to digest the food that we need for proteins and so on.

Enzymes get used over and over again, so the body only has a small amount. The reaction can only take place because of the lock and key action the enzymes have a specific shape of the for the thing that it is braking down e.g. there is an active site and if they don’t fit together correctly then the enzyme can not do its job to brake down the substance. But the enzymes can be useless when they are denatured this happens when their active site is changed around the 40-50°c. PH can also cause denature of the enzymes, most work at neutral PH, So extreme acidic or alkaline PH will denature them, a good example of this reaction is Peroxidase. When this happens they become useless to the body. There are a lot of certain enzymes for the right job, as you will see in the prediction section. There is three parts the enzyme and a part a and b they join together at the active site the molecules of substances combine with the enzyme for a short time. Then the enzyme frees to take part in another reaction. There has now been a new substance made a and b was joined together

AIM

To investigate how varying PH affects the activity of the peroxidase enzyme.

WHAT WILL BE MEASURED TO FIND THIS OUT?

The volume of oxygen (0 ) collected in the top of the measuring cylinder this will be measured in (mm’s ).

WHAT WILL BE DIFFERENT EACH TIME?

Each time the test is done the PH will change going from PH 3-PH 11.to see which will be the best PH for enzyme to work at. Using hydrochloric and acetic acids, water sodium carbonate and sodium hydroxide solutions.

WHAT WILL BE THE SAME EACH TIME?

...