Biology Chapter: Osmosis and Dialysis

Study Notes

Osmosis

Osmotic pressure is the tendency of a solution to absorb water due to its solute concentration (osmolarity).
Hydrostatic pressure is the pressure exerted by water from its volume or gravity.
Isotonic solutions have the same non-penetrating solute concentration as a cell's cytosol. This results in no net water movement.
Hypertonic solutions have a higher concentration of non-penetrating solutes than a cell. This causes water to leave the cell, leading to cell shrinkage (crenation). Crenation is characterized by a spiny or shriveled appearance of the cell.
Hypotonic solutions have a lower concentration of non-penetrating solutes than a cell. This causes water to enter the cell, leading to cell swelling (possible lysis). Lysis is the rupturing of the cell due to excessive swelling.

Dialysis

Dialysis is a passive process. It's the separation of different sized solute particles, utilized across a selectively permeable membrane.
Semipermeable membranes allow only small solute particles to pass through.
Hypertonic solutions have high osmotic pressure, high solute concentrations, and low free water.

False Statements (Chapter 6)

False: Osmotic pressure is the tendency of a solution to gain water due to its osmolarity. Strictly speaking it is the pressure needed to prevent further water movement.
False: Swelling is caused by hypotonic solutions; the lower solute concentration outside the cell draws water in, causing the cell to swell and possibly rupture.
False: Crenation happens in a hypertonic solution. The higher solute concentration outside the cell draws water out, causing the cell to shrink.

Description

Explore the concepts of osmosis and dialysis in this quiz. Understand the differences between isotonic, hypertonic, and hypotonic solutions, as well as the implications of osmotic and hydrostatic pressure. Test your knowledge on how these processes affect cells and their environments.