Control of Blood Glucose and Diabetes
Master Control of Blood Glucose and Diabetes for GCSE Biology with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Insulin and glucagon control blood glucose; be ready to compare the causes and treatments of Type 1 and Type 2 diabetes.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Blood glucose concentration is monitored and controlled by the pancreas, which produces two hormones with opposite effects.
If blood glucose is too high, the pancreas produces insulin. Insulin causes glucose to move from the blood into the cells, and in liver and muscle cells excess glucose is converted to glycogen for storage.
If blood glucose is too low, the pancreas produces glucagon. Glucagon causes glycogen stored in the liver to be converted back into glucose and released into the blood. Together these two hormones form a negative feedback cycle that keeps blood glucose within safe limits.
Revision notes
Insulin: lowering blood glucose
When blood glucose is too high, the pancreas secretes insulin.
Insulin causes glucose to move from the blood into body cells, where it is used in respiration. In liver and muscle cells, excess glucose is converted into glycogen for storage.
Glucagon: raising blood glucose
When blood glucose is too low, the pancreas secretes glucagon.
Glucagon causes glycogen stored in the liver to be converted back into glucose, which is released into the blood, raising the concentration.
Type 1 and type 2 diabetes
Type 1: the pancreas fails to produce enough insulin, giving uncontrolled high blood glucose. It is normally treated with insulin injections.
Type 2: the body cells no longer respond properly to insulin. Obesity is a risk factor. It is treated with a carbohydrate-controlled diet and exercise.
Key points
- The pancreas monitors and controls blood glucose.
- Insulin lowers blood glucose.
- Insulin causes glucose to be stored as glycogen.
- Glucagon raises blood glucose.
- Type 1 diabetes is a failure to produce insulin.
- Type 2 diabetes is cells not responding to insulin.
Worked examples
Example 1
Explain how the body responds when blood glucose concentration is too high. [3 marks]
Model answer
The pancreas detects the high concentration and secretes insulin (1 mark). Insulin causes glucose to move from the blood into the body cells (1 mark), and in the liver and muscles excess glucose is converted into glycogen for storage (1 mark).
Example 2
Describe the difference between type 1 and type 2 diabetes. [2 marks]
Model answer
In type 1 diabetes the pancreas does not produce enough insulin (1 mark). In type 2 diabetes the body cells no longer respond properly to the insulin that is produced (1 mark).
Example 3
Explain the role of glucagon in controlling blood glucose. [2 marks]
Model answer
Glucagon is secreted by the pancreas when blood glucose is too low (1 mark). It causes glycogen stored in the liver to be converted back into glucose, which is released into the blood (1 mark).
Common mistakes
Confusing glucagon with glycogen.
Glucagon is the hormone; glycogen is the stored carbohydrate. The names are close but the meanings are not.
Saying insulin converts glucose to glycogen directly.
Insulin causes the conversion to happen in the liver and muscles; it is not itself an enzyme.
Mixing up the two types of diabetes.
Type 1 is insufficient insulin; type 2 is cells not responding.
Saying type 2 diabetes is treated with insulin injections.
It is normally treated with a controlled diet and exercise.
Exam tips
- Write glucagon and glycogen out carefully — the spelling matters.
- Give the full chain: detection, hormone, effect on glucose.
- Learn both diabetes types and their treatments.
- Name the pancreas as both the monitor and the source of the hormones.
Key terms
- Insulin
- The hormone that lowers blood glucose concentration.
- Glucagon
- The hormone that raises blood glucose concentration.
- Glycogen
- The storage carbohydrate found in liver and muscle.
- Negative feedback
- A control mechanism that reverses a change from the norm.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.