Final answer:
Insulin is a non-steroid, peptide hormone produced by the pancreas, comprised of two peptide chains linked by disulfide bonds, facilitating glucose uptake into cells and reducing blood glucose levels.
Step-by-step explanation:
Insulin is a type of non-steroid hormone, which falls under the category of protein hormones, or more specifically, peptide hormones. It is an endocrine hormone that is secreted by the beta cells of the pancreas and plays a crucial role in regulating blood glucose levels. Engaging with insulin’s chemical structure, we find that bovine serum insulin is made up of two peptide chains: Chain A, which is 21 amino acids long, and Chain B, which has 30 amino acids. The amino acid cysteine in each chain contributes to the formation of disulfide bonds, which are essential for the hormone’s structure and function. These disulfide bonds not only connect the two peptide chains together but also facilitate the proper folding of the hormone.
Upon release, insulin binds to receptors on the surface of target cells, initiating a cascade of signals that influence the cell’s function. Specifically, it activates an enzyme in the plasma membrane, which then controls a second messenger molecule affecting cellular activities. Insulin’s primary role in the body is to aid cells in taking up glucose from the blood, thus decreasing the blood glucose level, which is especially important after a meal when blood glucose levels rise.