The sodium-glucose symporter is a protein found in the cell membrane that helps transport both sodium ions and glucose molecules across the cell membrane. It utilizes the energy obtained from the movement of sodium ions down their concentration gradient to actively transport glucose against its concentration gradient into the cell.
The correct answer to what powers the sodium glucose symporter is the sodium gradient. This means that the symporter uses the energy from the movement of sodium ions from an area of high concentration to an area of low concentration (down the sodium gradient) to drive the transport of glucose into the cell against its concentration gradient.
In contrast, ATP is not directly involved in powering the sodium-glucose symporter. While ATP is a common energy source for many cellular processes, in this case, the symporter relies on the energy derived from the sodium gradient to carry out its function efficiently.
