Question bank1.2 What happens in cells (and what do cells need)?

1.2 What happens in cells (and what do cells need)?

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Question 38

Amylase is an enzyme that breaks down starch.

A student investigates the effect of pH on the activity of amylase.

She mixes starch solution and amylase solution at pH 4.
Every 30 seconds she puts a drop of the mixture onto a drop of iodine solution on a spotting tile.
She records the time taken until the iodine solution no longer turns blue-black.
She repeats this at different pH values.

The Table shows her results.

Table

pH	Time taken until starch is no longer present in $s\text{s}$
4	300
5	180
6	60
7	90
8	240

Identify the independent variable in this investigation.

[1]

Use the Table to give the optimum pH of amylase.

[1]

State the colour of the iodine solution when starch is no longer present.

[1]

The rate of reaction can be calculated using this equation:

$rate=1000time\text{rate} = \dfrac{1000}{\text{time}}$

Calculate the rate of reaction at pH 7.

Give your answer to 1 decimal place.

[2]

Question bank1.2 What happens in cells (and what do cells need)?

1.2 What happens in cells (and what do cells need)?

Question 38

Amylase is an enzyme that breaks down starch.

A student investigates the effect of pH on the activity of amylase.

She mixes starch solution and amylase solution at pH 4.
Every 30 seconds she puts a drop of the mixture onto a drop of iodine solution on a spotting tile.
She records the time taken until the iodine solution no longer turns blue-black.
She repeats this at different pH values.

The Table shows her results.

Table

pH	Time taken until starch is no longer present in $s\text{s}$
4	300
5	180
6	60
7	90
8	240

Identify the independent variable in this investigation.

[1]

Use the Table to give the optimum pH of amylase.

[1]

State the colour of the iodine solution when starch is no longer present.

[1]

The rate of reaction can be calculated using this equation:

$rate=1000time\text{rate} = \dfrac{1000}{\text{time}}$

Calculate the rate of reaction at pH 7.

Give your answer to 1 decimal place.

[2]

1.2 What happens in cells (and what do cells need)?

Question 38

Markscheme

1.2 What happens in cells (and what do cells need)?

Question 38

Markscheme

1.2 What happens in cells (and what do cells need)?

Question 38

1.2 What happens in cells (and what do cells need)? Questions

1.2 What happens in cells (and what do cells need)?

Question 38

1.2 What happens in cells (and what do cells need)? Questions