similarities and differences betweemn osmosis and diffusion

Osmosis is a particular type of diffusion, one in which water passes through the semi-permeable membrane of a cell. Diffusion, broadly defined, is the process by which molecules and particles move from areas of high concentration to areas of lesser concentration. Osmosis refers to the type of diffusion in which the particle that is moved is water.

1. Osmosis

   • Osmosis occurs across a semi-permeable cell membrane, which means a cell membrane that contains holes through which certain molecules can pass but others cannot. For example, plant roots can absorb water through osmosis. This occurs because the soil surrounding the roots has a higher concentration of water than the cells that are adjacent to the soil. As a result, the water goes from a place of higher concentration (the soil) to a place of lower concentration (the cell). This process occurs until both the cells in the roots and the cells in the soil have the same density of water.
     

   Diffusion

   • Diffusion is the process by which molecules go from areas of higher concentration to lower concentration. This is essentially the same as osmosis, except that it encompasses a broad range of molecules, and not simply water. There are many types of diffusion other than osmosis, such as electron diffusion, gaseous diffusion, momentum diffusion and self-diffusion. Diffusion is a spontaneous process, and it follows in accordance with the Second Law of Thermodynamics, which states that all things tend towards complexity and spontaneity.
     

   Similar Characteristics

   • Both diffusion and osmosis involve a substance that moves from an area of higher concentration to an area of lower concentration, which occurs through a semi-permeable membrane. The semi-permeable membrane, in both cases, has a concentration discrepancy, in which one side of the membrane contains a higher concentration of something than the other side. This causes pressure, which can be called diffusion pressure or osmotic pressure.
     

   Plants and Animals

   • Osmosis helps animals and plants distribute nutrients and release waste. In plants, it helps the roots absorb water and elevate liquid to the leaves of the plants. Diffusion helps both plants and animals distribute nutrients, such as water, oxygen or carbon dioxide, throughout the plant or animal. Diffusion plays a large role in photosynthesis in plants, provided leaves with the needed nutrients for synthesizing glucose and natural sugars.