In some cells, there are many ion electrochemical gradients across the plasma membrane even though there are usually only one or two proton pumps present in the membrane. The gradients of the other ions are most likely accounted for by ________.
A) cotransport proteins
B) ion channels
C) pores in the plasma membrane
D) passive diffusion across the plasma membrane
E) cellular metabolic reactions that create or destroy ions

Question

Quizplus · Accepted Answer

Cotransport proteins are capable of using the energy of the electrochemical gradient of one ion to actively transport another ion against its own electrochemical gradient. This means that one proton pump can indirectly create electrochemical gradients for multiple ions.

In Some Cells, There Are Many Ion Electrochemical Gradients Across