Which of the following statements best describes the role of insulin in the body?

• A. Insulin promotes the uptake of glucose into cells, thereby lowering blood glucose levels.
• B. Insulin stimulates the breakdown of glycogen to increase blood glucose levels.
• C. Insulin increases gluconeogenesis in the liver.
• D. Insulin inhibits the synthesis of fatty acids in adipose tissue.

Answer: (A)

Verified step by step guidance

1. Understand the role of insulin: Insulin is a peptide hormone produced by the beta cells of the pancreas. Its primary function is to regulate blood glucose levels by promoting glucose uptake into cells, especially muscle and adipose tissue.
2. Analyze the first statement: 'Insulin promotes the uptake of glucose into cells, thereby lowering blood glucose levels.' This aligns with insulin's primary function, as it facilitates glucose transport into cells via GLUT4 transporters, reducing blood glucose levels.
3. Evaluate the second statement: 'Insulin stimulates the breakdown of glycogen to increase blood glucose levels.' This is incorrect because insulin actually promotes glycogen synthesis (glycogenesis) in the liver and muscle, storing glucose rather than breaking it down.
4. Assess the third statement: 'Insulin increases gluconeogenesis in the liver.' This is incorrect because insulin inhibits gluconeogenesis, which is the production of glucose from non-carbohydrate sources, as part of its role in lowering blood glucose levels.
5. Review the fourth statement: 'Insulin inhibits the synthesis of fatty acids in adipose tissue.' This is incorrect because insulin promotes lipogenesis (fatty acid synthesis) in adipose tissue, encouraging energy storage in the form of fat.