Osmosis is a type of diffusion that, in biology, is usually related to cells. Diffusion is when molecules or atoms move from an area of high concentration to an area of low concentration. Osmosis is when a substance crosses a semipermeable membrane in order to balance the concentrations of another substance.

Diffusion is a physical process that refers to the net movement of molecules from a region of high concentration to one of lower concentration. For instance, a gas diffuses very quickly in another gas. An example of this is the way the noxious smell of ammonia gas spreads in air.

Some examples of diffusion that occurs in our daily life are given below.

• The smell of perfumes/Incense Sticks.
• Opening the Soda/Cold Drinks bottle and the CO2 diffuses in the air.
• Dipping the tea bags in hot water will diffuse the tea in hot water.
• Small dust particles or smoke diffuse into the air and cause air pollution.

2)A teabag placed in a cup of hot water will diffuse into the water. 3)Placing food coloring in a liquid will diffuse the color. 4)Digested particles of the food diffuses in the colon. 5)A helium balloon will deflate a small amount everyday as helium diffuses through the balloon into the air.

Respiration is an example of diffusing gas molecules that takes places in the lungs. The oxygen we inhale is exchanged for carbon dioxide in tiny air sacs in the lungs. These blood cells move the oxygen across the body where it diffuses into other cells requiring oxygen.

Ventilation is the process by which air moves in and out of the lungs. Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

How long does diffusion last? Until it reaches equilibrium, when there is an equal amount of the substance distributed everywhere.