What hormone facilitates the transport of glucose across cell membranes?

Insulin is the hormone that facilitates the transport of glucose across cell membranes, particularly in muscle and adipose (fat) tissues. When blood glucose levels rise, such as after eating, the pancreas releases insulin into the bloodstream. Insulin binds to its specific receptors on cell membranes, which triggers various cellular processes that increase the number of glucose transporters (such as GLUT4) on the cell surface. This allows glucose to enter the cells more readily, where it can be used for energy or stored as glycogen.

The action of insulin is crucial for maintaining blood glucose homeostasis, and it plays a significant role in the body's metabolism. Without sufficient insulin or the ability of cells to respond to it, glucose cannot effectively enter cells, leading to elevated blood sugar levels, which can result in conditions like diabetes.

In contrast, adrenaline is primarily involved in the fight-or-flight response and helps increase blood glucose levels by stimulating the liver to release glucose. Cortisol is a stress hormone that can also raise blood glucose levels but does so by promoting gluconeogenesis in the liver. Glucagon, on the other hand, works in opposition to insulin, stimulating the liver to convert glycogen back into glucose and release it into the bloodstream. Each of these hormones has