What is Osmosis?

Osmosis is defined as the movement of water from a higher concentration to a lower concentration through a semipermeable membrane. But what does this mean? We will find this out in this article.

An example of osmosis is when you put a semi permeable membrane in the middle of a cup and add dilute sugar solution on one side cup and add concentrated solution on the other side. After a while the dilute sugar solution will have less water than it had before and the concentrated sugar solution will have more water than before. This movement between the two solutions will take place until both sides have a balanced amount of water.

The movement of a liquid depends on the amount of substance dissolved in it. An experiment which proves this is if you take three different petri dishes where one is with more salt dissolved than water, the second one where salt and water are equal and one where the water is more than the salt and add RBCs(red blood cells) in each. You will see that in the petri dish with more salt, the red blood cells would be shrinked, the one where salt and water are same, the RBCs would be same and where there is more water the RBCs would have bulged up.

In the case of one with more salt dissolved than water, the water in the RBCs moved out of the cell to balance the amount of water. This resulted in the RBCs to shrink and lose their shape. In the case of the water and salt being equal, both inside the RBCs and the mixture of salt and water would have a balanced amount of water. So the RBCs didn't change shape. In the case where there is more water and less salt, the mixture had more water content than the RBCs. The water from outside moved into the RBCs to maintain balance of water, thus making the RBCs bulged up.