AQA
A-Level
BIOLOGY
Organisms Respond to Changes in Environments
Control of Blood Glucose
Time allowed
54 minutes
QUESTION PAPER
Score Percentage
/45 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,Resource A
A glucometer is a device used to measure blood glucose concentration. A person uses a
test strip that goes into the glucometer. They put a drop of blood onto the test strip. There
are substances on the test strip that produce a colour change with glucose. The higher the
concentration of glucose, the deeper the colour produced. The glucometer measures the
depth of colour produced and converts this into a glucose concentration. A new test strip
is used for each blood test.
Figure 1 – glucometer and test strip
The following equations show how the substances on the test strip produce a colour
change.
Glucose + oxygen gluconic acid + hydrogen peroxide
Hydrogen peroxide + dye with colour A dye with colour B + water
Non-diabetics have no glucose in their urine. Diabetics have glucose in their urine if their
blood glucose concentration rises above about 170 mg 100 cm–3.
Before the glucometer was available, diabetics used test strips to measure the
concentration of glucose in their urine as a means of measuring their blood glucose
concentration. When testing urine, the colour of the test strip is compared against a colour
chart which gives a glucose concentration range for the colour produced.
, Resource B
There are two types of diabetes: type 1 and type 2.
• People with type 1 diabetes do not produce enough insulin.
• People with type 2 diabetes do produce insulin but have cells which do not respond
to insulin.
Doctors use a glucose tolerance test to help diagnose people with diabetes. They start
each test after a person has not eaten overnight. They measure a person’s blood glucose
concentration.
The person then drinks a solution containing 75 g of glucose. The doctors measure the
person’s blood glucose concentration 2 hours later. During the test, the person remains at
rest.
Figure 1 shows three diagnoses that can be made from the results of the test.
Figure 2 – glucose tolerance test results and diagnoses
Blood glucose
concentration after 2 hours Diagnosis Comments
/ mg 100 cm–3
≤ 110 Non-diabetic Low risk for future diabetes
High risk for future diabetes.
Some doctors recommend that the
Between 140 and 200 Pre-diabetic
upper value should be lowered to
180 mg 100 cm–3
≥ 200 Diabetic Confirm by doing a second test
A researcher monitored the mean blood glucose concentration of a non-diabetic, a
pre-diabetic and a diabetic after they had each eaten a midday meal.
His results are shown in Figure 3.
Figure 3
A-Level
BIOLOGY
Organisms Respond to Changes in Environments
Control of Blood Glucose
Time allowed
54 minutes
QUESTION PAPER
Score Percentage
/45 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,Resource A
A glucometer is a device used to measure blood glucose concentration. A person uses a
test strip that goes into the glucometer. They put a drop of blood onto the test strip. There
are substances on the test strip that produce a colour change with glucose. The higher the
concentration of glucose, the deeper the colour produced. The glucometer measures the
depth of colour produced and converts this into a glucose concentration. A new test strip
is used for each blood test.
Figure 1 – glucometer and test strip
The following equations show how the substances on the test strip produce a colour
change.
Glucose + oxygen gluconic acid + hydrogen peroxide
Hydrogen peroxide + dye with colour A dye with colour B + water
Non-diabetics have no glucose in their urine. Diabetics have glucose in their urine if their
blood glucose concentration rises above about 170 mg 100 cm–3.
Before the glucometer was available, diabetics used test strips to measure the
concentration of glucose in their urine as a means of measuring their blood glucose
concentration. When testing urine, the colour of the test strip is compared against a colour
chart which gives a glucose concentration range for the colour produced.
, Resource B
There are two types of diabetes: type 1 and type 2.
• People with type 1 diabetes do not produce enough insulin.
• People with type 2 diabetes do produce insulin but have cells which do not respond
to insulin.
Doctors use a glucose tolerance test to help diagnose people with diabetes. They start
each test after a person has not eaten overnight. They measure a person’s blood glucose
concentration.
The person then drinks a solution containing 75 g of glucose. The doctors measure the
person’s blood glucose concentration 2 hours later. During the test, the person remains at
rest.
Figure 1 shows three diagnoses that can be made from the results of the test.
Figure 2 – glucose tolerance test results and diagnoses
Blood glucose
concentration after 2 hours Diagnosis Comments
/ mg 100 cm–3
≤ 110 Non-diabetic Low risk for future diabetes
High risk for future diabetes.
Some doctors recommend that the
Between 140 and 200 Pre-diabetic
upper value should be lowered to
180 mg 100 cm–3
≥ 200 Diabetic Confirm by doing a second test
A researcher monitored the mean blood glucose concentration of a non-diabetic, a
pre-diabetic and a diabetic after they had each eaten a midday meal.
His results are shown in Figure 3.
Figure 3
