Glucose needs to be transported across the phospholipid bilayer into the cell so that it can be utilised (either for energy via ATP or stored as glycogen)
The phospholipid bilayer is virtually impermeable to glucose normally
Insulin binds to receptors on the cell and induces GLUT4 proteins
These glucose transporter proteins embed into the phospholipid bilayer and act like tunnels through which glucose can pass along its concentration gradient
