Final answer:
Insulin is a globular protein that is essential for regulating glucose metabolism in the body. It has a complex structure with disulfide bonds, and its proper shape is necessary for its function in transporting vital substances across cell membranes.
Step-by-step explanation:
Insulin is a globular protein and a critical hormone in regulating blood glucose levels. It is a polypeptide, consisting of two chains: chain A with 21 amino acids and chain B with 30 amino acids. The molecular weight of insulin is 5734 Da. Its structure includes disulfide bonds that stabilize its form, essential for its function.
Insulin plays a key role in metabolism by facilitating the transport of glucose, amino acids, potassium (K+), calcium (Ca²+), phosphorus (P), and nucleotides through the cell membrane. This allows for the proper utilization of glucose, maintaining the body's energy balance. Alterations in insulin's structure due to changes in temperature, pH, or chemical exposure can lead to denaturation and loss of function, highlighting the importance of its three-dimensional form for its action.
The design of insulin's peptide chains and its tertiary structure, observed in X-ray images, show the complexity and precision of its interaction with the body's cells. It originates from the pancreatic Islets of Langerhans cells and functions most effectively as a dimer when secreted into the bloodstream.