Osmosis Lab

For the past two days we've been learning about diffusion and osmosis.
Osmosis is a particular type of diffusion that involves water.
Diffusion is essentially the dispersion of a substance from a place with high concentration of itself to a place with low concentration. In the case of osmosis water is moving from a place of high concentration  of water (pure H20 or low molarity of solute) to a place with low concentration of water (high molarity of solute) through a semi permeable membrane.

A solution on one side of the membrane is hypertonic if has more solute particles than the other solution. The other solution would be hypotonic because it has less solute particles. To reach equilibrium/ homeostasis/ be isotonic, the hypotonic solution would send water to the hypertonic solution so that their solute concentrations average out. Water continues to move from side to side, but at the same rate so that the isotonic/ equal solute concentrations remain constant. 

Water potential describes the likelihood that water will enter a solution. the lower/ more negative it is, the higher the chance that it will be flooded. Water potential is equal to the pressure potential of the cell (so for plants it would be the cell wall pressure) plus the solute potential, which is 0 for pure water and goes increasingly negative as solute is added. Water potential is measured in bars, which are the same value as atms.

Our bodies contain water, so osmosis plays many integral roles in our organs. Our blood cells, for example, will burst if our blood contains too much water- the interiors of the blood cells become hypertonic to the blood and plasma, and because animal cells don't have cell walls to exert back pressure, the water will continue to enter the blood cell until the cell membrane rips open. The shards of burst cell could travel and lodge in bad places, or the cells could all pile up somewhere and cause an aneurysm. The opposite will happen if you are de-hydrated. Instead of bursting, your cells will shrivel up as all the water leaves the cell for the bloodstream. And the cells wouldn't be able to cary oxygen around as successfully.

We did a series of experiments on osmosis: pictures in next post