Correct Option
The correct option is 1 only
Explanation
Glucagon is a peptide hormone secreted by the alpha cells of the Islets of Langerhans in the pancreas. It acts as a hyperglycemic hormone, playing a critical role in maintaining normal blood glucose levels by functioning antagonistically to insulin.
Statement-wise Analysis
- Statement 1 is Correct: Glucagon is chemically a peptide hormone. It is synthesized and secreted in response to low blood glucose levels to restore homeostasis.
- Statement 2 is Incorrect: Glucagon acts primarily on liver cells (hepatocytes) and stimulates glycogenolysis (the breakdown of glycogen into glucose). This process releases glucose into the bloodstream, thereby increasing blood sugar levels. It does not inhibit this process. Additionally, it stimulates gluconeogenesis (the synthesis of glucose from non-carbohydrate sources).
- Statement 3 is Incorrect: Glucagon reduces cellular glucose uptake and utilization to ensure glucose remains available in the blood for vital organs. It is insulin that enhances cellular glucose uptake and utilization in hepatocytes and adipocytes, thereby lowering blood glucose levels.
Key Takeaway: Glucagon is a hyperglycemic hormone that increases blood glucose levels by promoting glycogenolysis and gluconeogenesis, whereas insulin is a hypoglycemic hormone that promotes cellular glucose uptake and glycogenesis.