Investigation on Enzymes

Investigation on Enzymes

Introduction

Sam and Sarah planned and carried out an experiment to see the effect

of pH on the activity of the enzyme amylase which breaks down starch

into sugar. They decided to investigate 5 different pH's 2,4,6,8 and

10.

1. The used a measuring cylinder to measure out 5cm3 of starch and

placed it in a test tube. They then added acid or alkali until they

got to pH2. They checked this using indicator paper

2. They placed the test tube in a rack on the bench and added 5cm3 of

amylase which they had also measured using a measuring cylinder.

3. Immediately, they took out a drop of the mixture and placed it on a

spotting tile which had 2 drops of Iodine in it. They repeated this

every 30 seconds until they knew all of the starch had been broken

down, so they stopped.

4. They then repeated the experiment at the different pHs'.

5. They did the experiment 3 times for each pH

Aim

Sam and Sarah planned to discover the effects of pH on the activity of

the enzyme amylase which breaks down starch into sugar.

Prediction

I predict that the pH that the enzyme will work best at is 8 because

amylase is mostly found in the mouth and salivary glands. This area is

normally slightly alkaline, so the pH that this enzyme would most

likely work best at would be 8.

Table

pH

2

4

6

8

10

1

2

3

1

2

3

1

2

3

1

2

3

1

2

3

Time (Min)

17

15

15

9

8.5

8.5

7

8

8

6

5.5

5

9