It is characterised by uncontrolled high blood glucose levels and is…

The idea

Because the pancreas of a person with Type 1 diabetes secretes insufficient insulin, glucose absorbed from the gut is not removed from the blood quickly enough. Blood glucose therefore rises after meals and is described as uncontrolled and high. Treatment replaces the missing hormone: insulin is injected, usually before meals, so that glucose can be taken up by liver and muscle cells and stored as glycogen. Insulin cannot be taken as a tablet because it is a protein and would be digested in the stomach.

What earns the marks

• Type 1 diabetes is characterised by blood glucose concentration rising above the normal range, especially after meals.
• The high level is described as uncontrolled because the body cannot regulate it with its own insulin.
• Treatment normally involves injecting insulin, which replaces the hormone the pancreas cannot make.
• Insulin is injected rather than swallowed because it is a protein and would be broken down by digestive enzymes.
• Injected insulin allows cells to take up glucose and store it as glycogen, lowering blood glucose.
• Dose and timing must be managed alongside diet and exercise to avoid blood glucose becoming too high or too low.

Common mistakes and how to put them right

• Writing that insulin is taken as a tablet.

  Put it right: Insulin is a protein and would be digested, so it is injected.

• Saying insulin injections cure diabetes.

  Put it right: They control blood glucose but do not restore the pancreas, so treatment is ongoing.

• Confusing the roles of insulin and glucagon.

  Put it right: Insulin lowers blood glucose, whereas glucagon raises it.

Exam tips

• Link the treatment to the cause: injections replace the insulin the pancreas cannot produce.
• Use comparative language such as higher than normal when describing blood glucose.
• When explaining why injection is needed, mention that insulin is a protein and would be digested if swallowed.