In cells lining the stomach, the movement of chloride ions into the cells is coupled to the transport of bicarbonate ions out of the cells.This type of transport system most likely uses
A) a uniporter.
B) a symporter.
C) a protein pump.
D) an antiporter.
E) graded diffusion.

Question

Quizplus · Accepted Answer

The transport system described in the question involves the movement of ions in opposite directions, which would require an antiporter. A uniporter transports a single type of molecule/ion in one direction, a symporter transports two different molecules/ions in the same direction, and a protein pump typically uses energy to move molecules/ions against their concentration gradient. Graded diffusion is not a type of protein-mediated transport system but rather refers to the gradual movement of particles from regions of higher concentration to regions of lower concentration.

In Cells Lining the Stomach, the Movement of Chloride Ions