Final answer:
Insulin signaling terminates when the hormone-receptor complex is degraded by lysosomes in the target cells.
Step-by-step explanation:
Insulin signaling terminates when the hormone-receptor complex is taken up by the lysosomes of the target cells and proteolysis occurs. This process involves the degradation of the insulin molecule and its receptors. Once an insulin molecule has docked onto the receptor and carried out its function, it may be released back into the extracellular environment or degraded by the cell. Degradation normally involves endocytosis of the insulin-receptor complex followed by the action of insulin degrading enzyme. The termination of insulin signaling is crucial to ensure proper regulation of glucose uptake and metabolism in the body.