Investigating the Rate of Reaction between Amylase and Starch

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Investigating the Rate of Reaction between Amylase and Starch



The aim of this investigation is to find out whether the volume of

amylase affects the rate of reaction between amylase and starch.


I predict that the greater the volume of amylase then the faster the

rate of reaction between the starch and amylase will be. I predict

this because of the lock and key hypothesis. The lock and key

hypothesis explains how the substrate molecule (the starch) fits

inside the enzyme. The substrate molecule is then broken up into many

smaller pieces.

In this experiment the larger the volume of amylase (enzyme/active

site) there is then the quicker the starch (substrate) will be broken

down, resulting in a fast reaction rate. Therefore, a smaller amount

of amylase will result in a slower reaction rate.


Text Box: Fischer’s ‘Lock and Key’ hypothesis (1890). Sequence of events when the union of a substrate with its enzyme occurs.

Preliminary Work:

The preliminary work was carried out to find a suitable range to

collect data in. From the preliminary work I was able to determine

suitable intervals of time to collect data. It showed that a volume of

amylase below 4cm³ took a very long time to react thus making the

experiment take too long. From this I worked out that I should start

at a volume of 4cm³. The preliminary work also proved to me that my

basic method worked without any set backs that may affect my results.


The variables involved in the rate of reaction between amylase and

starch are:

The volume of amylase

The volume of starch

The temperature of amylase

The temperature of starch

Room temperature


Ph values

The variable I will be changing is the volume of amylase.


To make sure I carry out this experiment safely I will make sure I

wear goggles. I will ensure I keep my stool under the table and all

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