Insulin receptor is a crucial heterotetrameric protein composed of two extracellular alpha subunits and two transmembrane beta subunits, which are connected by disulfide bonds. The alpha subunits are responsible for binding insulin, initiating conformational changes that activate the receptor′s intrinsic tyrosine kinase activity in the beta subunits. This structural configuration is vital for the receptor′s function in mediating insulin′s metabolic effects, such as facilitating glucose uptake into cells, promoting glycogen synthesis, and regulating various aspects of cellular metabolism and growth. Upon insulin binding, the receptor undergoes autophosphorylation of its tyrosine kinase domains, triggering a cascade of downstream signaling pathways that enhance glucose transport, increase cell permeability to monosaccharides, amino acids, and fatty acids, and maintain metabolic homeostasis.