A Report on the Effects of Osmolarity on Body Volume

Osmosis and Body Volume Lab Report

March 16, 2007

Introduction
The experiment focused on the different effects of osmosis on body volume in osmoregulators and osmoconformers. Osmosis is the diffusion of water across a selectively permeable membrane.1 and this diffusion of water is usually from a region of high concentration to a region of low concentration. A solution with a high concentration of solutes is called a hypertonic solution, while that with a low concentration of solutes is called a hypotonic solution. A solution with equal concentrations of solute and solvent is called an isotonic solution. Therefore in osmosis water moves, across a selectively permeable membrane, from a hypotonic solution to a hypertonic solution till both solutions are isotonic.

This is important biologically because all the cells in an organism "live" in an aqueous environment. A difference in the concentration gradient between a cell and the solution it is suspended in can result in osmosis. Animal cells do not have strong cell walls and if placed in a hypotonic solution, the cells swell as water diffuses into the cell till the cell finally bursts. In a hypertonic solution, animal cells shrivel up as water diffuses out of the cell. The best environment for an animal cell is an isotonic environment.