How does insulin affect the target cells and tissues to lower blood sugar?

Insulin lowers blood sugar levels by facilitating the uptake of glucose into target cells, primarily muscle and fat tissues. It binds to insulin receptors on the cell surface, triggering a signaling cascade that promotes the translocation of glucose transporter proteins (such as GLUT4) to the cell membrane. This allows more glucose to enter the cells, where it can be used for energy or stored as glycogen, effectively reducing the amount of glucose in the bloodstream. Additionally, insulin inhibits gluconeogenesis and glycogenolysis in the liver, further contributing to lower blood sugar levels.