Why is Osmosis Important?
Osmosis is movement of water from the region of its high concentration to the region of its low concentration through a semi-permeable membrane. Solution with high water concentration means there are only water molecules and no other solute is present in it. Low concentration of water means the concentration of solute is more and that of water is less. This is very important to remember when we talk about osmosis. The movement of water molecules will continue until the concentration of water remains equal on both sides.
Plant cells have cell wall surrounding the plasma membrane unlike that of animal cells. Plants absorb water from the soil through osmosis. The plant cell receives water to an extent that it swells and become more turgid. This turgidity results due to retaining of entered water inside. This is achieved by the cell wall of plant cell. This turgidity is essential for the survival of the plant as it helps in standing of the plant in erect fashion when sunlight falls on it. When plants are placed in highly concentrated solution, the water in the cells moves away to the surrounding solution. The loss of water in the plant cell leads to a condition called ‘Flaccid,. Turgid is opposite to flaccid. When the plant cells are flaccid, the plant droops and needs to be watered.
In animal cells, as there is no cell wall, the movement of water inside the cells will not make them turgid. Movement of water inside the animal cell or outside it will be dangerous. Hence, it is necessary for the animal cells to bath in solution with similar osmotic strength. The kidneys in animals aid in adjustment of water content and salt content in the blood. This type of regulation is called as osmoregulation. In order to survive, land animals and sea animals should conserve water in the body, while the fresh water animals should have a mechanism to push out the excess water that moves in, by osmosis. There are several homeostatic mechanisms that activate in all animals to balance water and salt content in the body. This mechanism is very important for the animals to survive.