Which of the Following is Used to Drive Glucose Uptake

Question

Which of the following is used to drive glucose uptake by intestinal epithelial cells?
A)potassium gradient across the blood vessel/epithelial cell membrane
B)potassium gradient across the intestinal lumen/epithelial cell membrane
C)sodium gradient across the blood vessel/epithelial cell membrane
D)sodium gradient across the intestinal lumen/epithelial cell membrane
E)none of the above

Accepted Answer

Intestinal epithelial cells use a sodium gradient across the intestinal lumen/epithelial cell membrane to drive glucose uptake through the sodium-glucose cotransporter 1 (SGLT-1) protein. As sodium ions move down their concentration gradient into the intestinal epithelial cell, glucose molecules are brought along with them against their concentration gradient, ensuring glucose absorption from the intestine.