Insulin is classified as what type of biological molecule?

Insulin is classified as a hormone, which is a type of biological molecule that functions as a signaling molecule in the body. Hormones are produced by glands and released into the bloodstream, where they travel to various tissues and organs to exert their effects on physiological processes. In the case of insulin, it is produced by the pancreas and plays a crucial role in regulating blood sugar levels by facilitating the uptake of glucose into cells for energy or storage.

Understanding insulin as a hormone is key to grasping its importance in metabolism and energy balance. It helps to maintain homeostasis, particularly in relation to glucose levels in the blood, making it integral for metabolic health. While insulin can also be classified as a protein due to its structure, within the context of this question, recognizing it primarily as a hormone captures its functional significance in the body.