Movement of glucose across cell membrane intestine?

The movement of glucose across the cell membrane of intestinal cells is facilitated by two main transport mechanisms:

1. Sodium-Glucose Cotransport (SGLT1):

- SGLT1 is a sodium-dependent glucose transporter located on the apical (brush border) membrane of intestinal cells.

- It utilizes the electrochemical gradient of sodium ions, created by the active transport of sodium ions from the intestinal lumen into the enterocytes (sodium-potassium ATPase pump), to drive the transport of glucose against its concentration gradient.

- Glucose and sodium ions bind to the SGLT1 transporter, and the energy from the sodium gradient powers the movement of both molecules into the enterocyte.

2. Glucose Transporter 2 (GLUT2):

- GLUT2 is a facilitative glucose transporter found on the basolateral membrane of intestinal cells, which faces the bloodstream.

- GLUT2 allows the transport of glucose down its concentration gradient, from the enterocyte into the bloodstream.

- The glucose that enters the enterocyte via SGLT1 is transported across the cell and exits into the bloodstream through GLUT2.

These transport mechanisms work in concert to facilitate the absorption of glucose from the intestinal lumen into the bloodstream. SGLT1 is responsible for the initial uptake of glucose against a concentration gradient, while GLUT2 enables its exit into the circulation.