In response to insulin, which transporter moves to the cell membrane to promote glucose entry into muscle and adipose tissue?

• A. SGLT2 Transporter
• B. GLUT4 Transporter
• C. GLUT1 Transporter
• D. GLUT2 Transporter

Answer: (B)

When insulin levels rise after a meal, the body boosts glucose uptake into muscle and fat by moving a specific transporter to the cell surface. In these tissues, the transporter that responds to insulin is GLUT4. The insulin signal triggers a cascade inside the cell that causes GLUT4-containing vesicles to fuse with the plasma membrane, increasing glucose entry from the blood into the cell.

Other transporters don’t fit this scenario in muscle and adipose tissue. SGLT2 is a kidney transporter that uses sodium to actively reabsorb glucose and is not the insulin-regulated transporter in muscle or fat. GLUT1 provides baseline glucose uptake in many tissues and isn’t the insulin-stimulated, translocation-based system used here. GLUT2 is found mainly in liver, pancreas, and intestine and operates differently, not by insulin-driven membrane translocation in muscle/adipose.

So the transporter that moves to the membrane in response to insulin to promote glucose entry into muscle and adipose tissue is GLUT4.