To investigate the effect of temperature on enzyme activity

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nzyme Activity

Aim – To investigate the effect of temperature on enzyme activity

Yeast + hydrogen peroxide yeast + water + oxygen

Planning

Introduction

Enzymes are extraordinarily efficient. Minute quantities of an enzyme can accomplish at low temperatures what would require violent reagents and high temperatures by ordinary chemical means. About 30g of pure crystalline pepsin, for example, would be capable of digesting nearly 2 metric tons of egg white in a few hours.

As a rule, enzymes do not attack living cells. As soon as a cell dies, however, enzymes that break down protein rapidly digest it. The resistance of the living cell is due to the enzyme's inability to pass through the membrane of the cell as long as the cell lives. When the cell dies, its membrane becomes permeable, and the enzyme can then enter the cell and destroy the protein within it. Some cells also contain enzyme inhibitors, known as antienzymes, which prevent the action of an enzyme upon a substrate.

Prediction

An enzyme is a protein molecule that speeds up chemical reactions in all living things. Without enzymes, these reactions would occur too slowly or not at all, and no life would be possible. All living cells make enzymes, but enzymes are not alive. Enzyme molecules function by altering other molecules. Enzymes combine with the altered molecules to form a complex molecular structure in which chemical reactions take place. The enzyme, which remains unchanged, then separates from the product of the reaction. Therefore, an enzyme is a sort of biological catalyst.

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Using existing scientific knowledge, it is predicted that as the temperature is raised to 30oC, 35oC, and 40oC, this is where the greatest reaction will be seen. This is predicted because enzymes are designed to react best at the body temperatures of the animals to which they belong. For a mammal, this is around 35-36oC. Catalysts are used to speed up biochemical reactions in the body. The enzymes are denatured at around 40oC. The shape of the enzymes changes to that they can no longer latch on to molecules and cause a reaction.

Variables


Variable:

The temperatures of the ...

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