Blood glucose regulation

Type 2 diabetes is a condition that has become more common in recent years.

Scientists recorded the percentage of people of different ages who had Type 2 diabetes.

The people were in different weight categories:

• healthy weight

• overweight

• obese.

Figure 10 shows the results.

Give two conclusions from the results in Figure 10.

Two groups of scientists investigated the use of different drugs to treat

Type 2 diabetes.

In both investigations, the scientists measured the percentage of haemoglobin with glucose attached (Hb-G). This showed the long-term concentration of glucose in the blood.

Investigation 1:

The scientists injected drug A into 175 patients with Type 2 diabetes once each day for 12 weeks.

Table 4 shows the results.

Investigation 2:

631 patients with Type 2 diabetes took one tablet containing drug B each day. A control group of 630 patients took a placebo tablet each day.

The scientists measured the Hb-G in each patient’s blood at the start of the investigation and at 6-week intervals up to 24 weeks.

Figure 11 shows the results.

For the patients treated with drug B the mean percentage of Hb-G at the start was 8.3%.

What was the mean percentage of Hb-G after 12 weeks for the patients treated with drug B ?

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In a person without diabetes, the Hb-G value is between 4.5% and 6%.

When treating patients with Type 2 diabetes, doctors think that an Hb-G value <7% is acceptable.

Evaluate:

• the methods used in the investigations

• the usefulness of drug A and drug B for controlling Type 2 diabetes.

The hormone insulin helps to control the concentration of glucose in the blood.

Which organ produces insulin?

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People with Type 2 diabetes:

• produce insulin

• have body cells that do not respond to insulin

• often have a high concentration of glucose in their blood.

Why do people with Type 2 diabetes often have a high concentration of glucose in their blood?

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Drug X is used for treating people who have Type 2 diabetes.

Scientists investigated the effect of drug X on the concentration of glucose in the blood of mice.

This is the method used.

1. Give two groups of mice the same diet for 8 weeks.

2. Give each mouse in group A 2 cm³ of water to drink.

3. Give each mouse in group B 2 cm³ of drug X to drink.

4. After 30 minutes, give each mouse 1 cm³ of glucose solution to drink.

5. Measure the concentration of glucose in the blood of each mouse at intervals for 3 hours.

Give two control variables used in the investigation.

Figure 6 shows the results.

In each group of mice, the concentration of glucose increases to a maximum value and then decreases.

Group B reached a maximum value earlier than group A.

Determine how many minutes earlier.

Give two conclusions about the effect of drug X on the concentration of glucose in the blood.

Do not refer to reaching the maximum value earlier.

How could scientists find the best dose of drug X for controlling blood glucose concentration?

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Hormones are important for controlling many processes in the human body.

Hormones are produced by glands.

Which organ system has glands that produce hormones?

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How are hormones transported around the body?

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Figure 1 shows glands in a woman’s body.

Draw one line from each gland to the name of that gland.

Which gland in Figure 1 produces insulin?

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Which organ does insulin mainly affect?

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Give one effect of insulin.

Some hormones control a woman’s menstrual cycle.

Which hormone causes an egg to mature in the ovary?

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Which two are hormones that help to maintain the lining of the uterus during pregnancy?

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Contraception prevents pregnancy.

Give two methods of contraception that use hormones.

It is important to control the concentration of glucose in the blood. Figure 13 shows how the concentration of glucose in the blood of a person changed over 4 hours.

Give one time when the concentration of insulin in the person’s blood would be high. Use Figure 13.

Explain the effect a high concentration of insulin has on blood glucose concentration.

People with diabetes have difficulty controlling the concentration of glucose in

their blood. Type 2 diabetes is linked to obesity. Figure 14 shows how to find if an adult’s body mass is healthy for their height.

Person A:

• is 1.75 m in height

• has a body mass of 52 kg.

What is person A ’s weight category? Tick (✓) one box.

Person B is 1.9 m in height. Give the range of body masses that would put person B in the healthy weight category.

Person C is obese. A doctor thinks that person C has Type 2 diabetes. The doctor tests a sample of blood from person C. Table 5 shows:

• the results of the blood test

• the mean results for people who do not have diabetes.

Type 2 diabetes occurs when body cells have a reduced response to insulin. Give two ways the results of the blood test show that person C might have Type 2 diabetes.

Give two ways that a person can reduce the chance of developing Type 2 diabetes.

It is important to control the concentration of glucose in the blood. Figure 2 shows how the concentration of glucose in the blood of a person changed over 4 hours.

Give one time when the concentration of insulin in the person’s blood would be high. Use Figure 2.

Explain the effect a high concentration of insulin has on blood glucose concentration.

People with diabetes have difficulty controlling the concentration of glucose in

their blood. Type 2 diabetes is linked to obesity. Figure 3 shows how to find if an adult’s body mass is healthy for their height.

Person A:

• is 1.75 m in height

• has a body mass of 52 kg.

What is person A ’s weight category? Tick (✓) one box.

Person B is 1.9 m in height. Give the range of body masses that would put person B in the healthy weight category.

Person C is obese. A doctor thinks that person C has Type 2 diabetes. The doctor tests a sample of blood from person C. Table 2 shows:

• the results of the blood test

• the mean results for people who do not have diabetes.

Type 2 diabetes occurs when body cells have a reduced response to insulin. Give two ways the results of the blood test show that person C might have Type 2 diabetes.

Give two ways that a person can reduce the chance of developing Type 2 diabetes.

Many internal processes of the human body are controlled by hormones. Hormones are produced by glands. Figure 2 shows glands in a woman’s body.

Which gland is the pituitary gland?

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Which gland is the pancreas?

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The hormone insulin helps to decrease the blood glucose concentration. Insulin causes its target organs to take in glucose from the blood.

Which of the following is a target organ for insulin?

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The glucose is stored as an insoluble substance. What is the insoluble storage substance that is formed from glucose?

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Scientists investigated the effect of a glucose drink on the concentration of glucose in

a person’s blood. This is the method used.

1. Take a small sample of blood from the person.

2. Measure the concentration of glucose in the person’s blood.

3. Give the person a drink containing 50 grams of glucose.

4. Measure the concentration of glucose in the person’s blood at intervals.

5. Calculate the change in blood glucose concentration from the starting value.

Figure 3 shows the results.

Figure 3 shows the change in blood glucose concentration.

At the start of the investigation, the blood glucose concentration was 5 mmol/dm³. Calculate the highest blood glucose concentration during the investigation. Use information from Figure 3 in your answer.

What is the time taken for the blood glucose concentration to decrease from its highest value back to the starting value? Use data from Figure 3 in your answer.

Why can you not be certain that your answer to Question 02.6 is accurate?

Figure 3 shows the results for a person who does not have Type 2 diabetes. Sketch a line on Figure 3 to show the results you would expect for a person who has

It is important to keep the blood glucose concentration within narrow limits.

A person eats a meal containing a lot of carbohydrate. This causes an increase in the person’s blood glucose concentration.

Explain how the hormones insulin and glucagon control the person’s blood glucose concentration after the meal.

The body cells of a person with Type 2 diabetes do not respond to insulin.

A person with Type 2 diabetes often has a higher blood insulin concentration than a non-diabetic person.

Explain why.

Metformin is a drug used for treating people who have Type 2 diabetes.

Scientists investigated the effects of metformin and two other drugs, A and B.

The scientists wanted to see how the drugs affected the blood glucose concentrations of 220 people with Type 2 diabetes.

This is the method used.

1. Put the 220 people into five groups.

2. Treat each group with a different drug or combination of drugs for several weeks.

3. Give each person a meal high in carbohydrate.

4. Measure the blood glucose concentration of each person 30 minutes after the meal and again 3 hours after the meal.

Suggest three variables that the scientists should have controlled in the investigation.

The scientists recorded their results as a mean value for each group.

The scientists calculated the ‘standard deviation’ for each group’s result.

Standard deviation is a measure of the spread of the individual results above or below (±) the mean value.

The scientists gave each group’s result as:

mean ± standard deviation

The larger the standard deviation, the greater is the spread of results around the mean.

Which of the results is the most precise?

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Table 3 and Figure 9 show the scientists’ results.

In Table 3 and Figure 9 some standard deviations of results overlap.

• An overlap of standard deviations shows the difference between the means is not significant.

• No overlap of standard deviations shows a significant difference between the means.

A student looked at the scientists’ method and the results in Table 3 and Figure 9.

The student stated:

‘Metformin works better when used with other drugs.’

Evaluate the student’s statement.

A person with Type 1 diabetes cannot make enough insulin.

Which organ makes insulin?

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A person with Type 1 diabetes can control the concentration of glucose in the blood by injecting insulin.

Complete the sentences.

Choose answers from the box.

Insulin acts on an organ called the.

This organ then takes in excess glucose from the blood and changes

Insulin cannot be taken as a tablet. This is because insulin is a type of protein.

What would happen to the insulin in the tablet if it reached the stomach?

Two people each drank the same volume of a glucose drink. Person A has Type 1 diabetes. Person B does not have diabetes.

Figure 6 shows how the concentration of glucose in their blood changed.

How much higher was the highest concentration of glucose in the blood of person A than the highest concentration in person B ?

Use information from Figure 6.

Describe one other way that the results for person A were different from the results for person B.

Use information from Figure 6.

Type 2 diabetes is another form of diabetes. Type 2 diabetes is common in obese people.

People with Type 2 diabetes make enough insulin, but still cannot control their blood glucose concentration. This is because the body cells are not sensitive to the insulin.

Figure 7 shows information about abdominal fat and insulin sensitivity in body cells.

What type of relationship is shown in Figure 7 ?

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A person is at risk of developing Type 2 diabetes.

Suggest two ways the person could lower the chance of developing Type 2 diabetes.