Question 5a (ii)

1. Initial Glucose and Insulin Levels (Before Glucose Intake)

• Blood Glucose: Stable at approximately 4.2 mmol/dm³ before the glucose solution is taken.
• Insulin: Low at 2 mmol/dm³, reflecting a fasting state.

2. After Glucose Intake (0 to 1 Hour)

• Blood Glucose Spike: Blood glucose levels increase from 4.2 to 6.8 mmol/dm³, indicating glucose absorption from the drink.
• Insulin Response: Insulin concentration sharply rises from 2 to 10 mmol/dm³, as pancreatic beta cells release insulin in response to higher blood glucose.

3. Two Hours Post-Glucose Intake

• Blood Glucose Regulation: Blood glucose decreases slightly to 6 mmol/dm³ as insulin facilitates glucose uptake by cells.
• Decrease in Insulin: Insulin levels reduce to 6.6 mmol/dm³, as the glucose levels start to drop and less insulin is needed.

4. Three to Five Hours Post-Glucose Intake

• Return to Baseline Glucose: Blood glucose gradually returns to around 4.2 mmol/dm³, close to the initial fasting level.
• Insulin Stabilization: Insulin concentration decreases to near baseline (around 2 mmol/dm³), as blood glucose is regulated.

Summary

• Insulin levels decrease gradually as blood glucose normalizes, showcasing the negative feedback mechanism in glucose regulation.
• Pancreatic Beta Cells respond to elevated blood glucose by releasing insulin, which facilitates glucose uptake and lowers blood glucose back to baseline levels.