File Name: difference between diffusion and osmosis .zip
Most users should sign in with their email address. If you originally registered with a username please use that to sign in.
Easy Biology Class
Osmotic pressure is a colligative property , meaning that the osmotic pressure depends on the molar concentration of the solute but not on its identity. Osmosis is a vital process in biological systems , as biological membranes are semipermeable. In general, these membranes are impermeable to large and polar molecules, such as ions , proteins , and polysaccharides , while being permeable to non-polar or hydrophobic molecules like lipids as well as to small molecules like oxygen, carbon dioxide, nitrogen, and nitric oxide. Permeability depends on solubility, charge, or chemistry, as well as solute size. Water molecules travel through the plasma membrane, tonoplast membrane vacuole or protoplast by diffusing across the phospholipid bilayer via aquaporins small transmembrane proteins similar to those responsible for facilitated diffusion and ion channels. Osmosis provides the primary means by which water is transported into and out of cells. The turgor pressure of a cell is largely maintained by osmosis across the cell membrane between the cell interior and its relatively hypotonic environment.
Diffusion and osmosis
In order to function, cells are required to move materials in and out of their cytoplasm via their cell membranes. These membranes are semipermeable, meaning that certain molecules are allowed to pass through, but not others. This movement of molecules is mediated by the phospholipid bilayer and its embedded proteins, some of which act as transport channels for molecules that otherwise would not be able to pass through the membrane, such as ions and carbohydrates. One reason cells are so small is the need to transport molecules into, throughout, and out of the cell. There is a geometrical constraint on cells due to the relationship between surface area and volume that limits the ability to bring in enough nutrients to support a larger cell size.
Osmosis and diffusion play essential, but distinct roles in the human body. Diffusion sees molecules in an area of high concentration move to areas with a lower concentration, while osmosis refers to the process by which water, or other solvents, moves through a semipermeable membrane, leaving other bits of matter in its wake. For example, oxygen diffuses into red blood cells, and salt placed outside a cell will draw out the cell's water through osmosis, dehydrating it. While they seem similar, they have different mechanisms of action and purposes in Earth's many species. Gases and substances dissolved in a liquid diffuse from an area of high concentration to one of low concentration. For example, if you spray perfume into the air, the volatile perfume molecules will spread out in the air from the concentrated point of origin.
Osmosis: Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution.
Easy Biology Class
To answer the question, you need to know the definitions of osmosis and diffusion and really understand what they mean. Osmosis and diffusion are related processes that display similarities:. Here's how they are different:. Facts to remember about diffusion and osmosis:. Share Flipboard Email.
Osmosis and diffusion are the two distinct forms of passive transport that play an essential role in transporting molecules through and out of the cell. Students are mostly asked to clarify the similarities and disparities between osmosis and diffusion or to compare the two modes of transport and contrast them.