Question

the bacterial na -h symporter is a secondary active transport protein that pumps na from inside the cell to the extracellular space against its concentration gradient. energy from this is derived from the coupled flow of h ions. based on the flow of h ions. Is the extracellular ph higher or lower than the intracellular ph in this symporter, and why?

Answer 1

The extracellular pH is lower than the intracellular pH due to the activity of the Na+-H+ symporter, which moves H+ ions out of the cell, thus increasing the acidity outside the cell.

Step-by-step explanation:

The extracellular pH is lower than the intracellular pH because the action of the sodium-hydrogen (Na+-H+) symporter moves H+ from the cell to the extracellular space. This transfer of H+ (protons) into the extracellular space increases the proton concentration outside the cell, which in turn lowers the pH, making it more acidic compared to the inside of the cell. Symporters are a type of secondary active transport system that moves two substances in the same direction through the cell membrane.

The case of the sodium-hydrogen symporter, the inward flow of Na+ ions down its concentration gradient is coupled with the outward flow of H+ ions against their concentration gradient. The energy derived from the movement of sodium ions into the cell is used to expel hydrogen ions, contributing to the maintenance of intracellular pH.