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 inhibits the synthesis of fatty acids in adipose tissue.
• C. Insulin stimulates the breakdown of glycogen to increase blood glucose levels.
• D. Insulin increases gluconeogenesis in the liver.

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 the uptake of glucose 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 the primary function of insulin, as it facilitates glucose transport into cells via GLUT4 transporters, reducing blood glucose levels.
3. Evaluate the second statement: 'Insulin inhibits the synthesis of fatty acids in adipose tissue.' This is incorrect because insulin actually promotes fatty acid synthesis in adipose tissue by activating enzymes like acetyl-CoA carboxylase.
4. Evaluate the third statement: 'Insulin stimulates the breakdown of glycogen to increase blood glucose levels.' This is incorrect because insulin inhibits glycogenolysis (glycogen breakdown) and promotes glycogenesis (glycogen synthesis) to lower blood glucose levels.
5. Evaluate the fourth statement: 'Insulin increases gluconeogenesis in the liver.' This is incorrect because insulin suppresses gluconeogenesis (glucose production from non-carbohydrate sources) in the liver, as its role is to lower blood glucose levels.