MHT CET Medical202622 April 2026Morning ShiftBiologyTransport in PlantsActual
The kind of passive absorption of anions against the concentration gradient, in order to neutralize the effect of fixed cations in the cell, is called ____.
Options
- Aosmotic absorption
- BDonnan equilibrium
- Cfacilitated diffusion
- Dantagonism
Correct answer
B. Donnan equilibrium
Step-by-step solution
Donnan equilibrium is a passive process that accounts for the accumulation of ions against their concentration gradient without the expenditure of metabolic energy (ATP). When a cell contains fixed, non-diffusible ions (such as proteins or organic molecules with a net charge), it creates an electrical imbalance. To neutralize the effect of these fixed cations or anions, diffusible ions of the opposite charge from the external medium passively diffuse into the cell. This movement occurs against the concentration gra