Question

How do organisms protect from osmotic stress?

Answer 1

Osmotic shock or osmotic stress is physiologic dysfunction caused by a sudden change in the solute concentration around a cell, which causes a rapid change in the movement of water across its cell membrane.

All organisms have mechanisms to respond to osmotic stress, with sensor and signal transduction networks providing o the cell about the osmolarity of its surroundings, these signals activate responses to deal with extreme conditions. Although single-celled organisms are more vulnerable to osmotic shock since they are directly exposed to their environment, cells in large animals such as mammals still suffer these stresses under some conditions.

For hypertonic osmotic stress:

Extracellular sequestering if calcium by blood albumin. Transient intracellular calcium increase can decrease such type of stress.

For hypotonic osmotic stress:

Calcium-dependent efflux of the osmolyte taurine. Extracellular calcium removal was found to prevent taurine. Taurine efflux by 50% and removal of extracellular calcium and simultaneously depletion of intracellular calcium stress with thapsigargin decreased by 85%.

If the osmotic pressure inside becomes too great than the membrane strength the cell ruptures. Plant cells have rigid cell walls of cellulose around them to protect them from such osmotic shock. To redress the balance and reestablish equilibrium the temperature or the pressure of the physiological solution must be adjusted.