Question

You have discovered a membrane transporter that mediates the import of Leucine into the cytosol from the bloodstream. It utilizes the electrochemical gradient of Cl- to pump Leucine uphill the concentration gradient. You replaced blood with an isotonic solution that contains the equal concentration of Leucine as in the bloodstream but without any Cl-. What will happen?

Leucine will be actively transported out from the cytosol 0 Leucine doesn't need an active transport since its side chain is non-polar CH WI will be actively imported while leucine gets exported The concentration of leucine inside and outside of cells will become the same

Answer 1

4) The concentration of leucine inside and outside will remain same.

Leucine cannot be transported either side in the absence of chloride ion. This chloride ions are responsible for movement of leucine across the electrochemical gradient.