Question

Ions diffuse freely along their (i)___, from the region of (ii)___ concentration and (iii)___ charge to the region of (iv)___ concentration and (v)___charge.

• A. (i) concentration gradient, (ii) high, (iii) opposite, (iv) low, (v) similar
• B. (i) electrochemical gradient, (ii) high, (iii) opposite, (iv) low, (v) similar
• C. (i) concentration gradient, (ii) high, (iii) similar, (iv) low, (v) opposite
• D. (i) electrochemical gradient, (ii) high, (iii) similar, (iv) low, (v) opposite

Answer 1

The correct option is D (i) electrochemical gradient, (ii) high, (iii) similar, (iv) low, (v) opposite

Ions diffuse freely across a semi-permeable membrane only through ion channels. They move along their electrochemical gradient, that is not only from the region of high concentration to low concentration but also from a region of similar charge to region of opposite charge moving the system towards electroneutrality. Therefore ions diffuse freely along their electrochemical gradient, from region of high concentration and similar charge to region of lower concentration and opposite charge.