The sodium (Na⁺)/glucose cotransporter 1 (SGLT1) is found in the apical membrane of epithelial cells of the small intestine as well as in the apical membrane of the epithelial cells of the kidney proximal tubules. In the small intestine, SGLT1 is responsible for glucose and galactose absorption across the brush border membrane of small intestinal cells. In the kidney proximal tubules, SGLT1 plays an important role in glucose reabsorption across the brush border membrane of proximal tubular cells. The ion/substrate stoichiometry of SGLT1 is: