Question

A particular cell has an internal chloride concentration of 50 mM, while the outside the cell the chloride ion concentration is 100 mM. Movement of chloride into the cell requires the input of energy. Which choice below is the best explanation for this data?

A. Both the concentration gradient and electrical gradient favor the movement of Cl- ions into the cell
B. The concentration gradient for Cl- ions favors movement into the cell, but the electrical gradient opposes inward movement of Cl-
C. Both the electrical and chemical gradients for Cl- ions favor outward movement of Cl- ions

Answer 1

The best explanation is choice B, where the concentration gradient favors movement of Cl- ions into the cell, but the electrical gradient opposes inward movement of Cl-.

Step-by-step explanation:

The best explanation for this data is choice B. The concentration gradient for Cl- ions favors movement into the cell, but the electrical gradient opposes inward movement of Cl-. The combination of the concentration gradient and electrical gradient affecting an ion is called its electrochemical gradient.