Question

What is diffusion , osmosis

Answer 1

Diffusion is when particles or objects move from an area of higher concentration to an area of lower concentration. Concentrationrefers to how much of a particular object or particle is in a given space. So in the example of the transit train, you went from an area of higher concentration of people to an area of a lower concentration of people. This means that you went through the process of diffusion. The overall goal of diffusion is for the particles or objects to reach equilibrium. Equilibrium is when the amount of the particles or objects are the same throughout a solution or are equally dispersed through a given area. Equilibrium will be reached with the train you were on if more people were to move to the other cars of the train so that each car has the same amount of people.


Osmosis is the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves across a selectively permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations.Osmosis can be made to do work.Osmotic pressure is defined as the external pressure required to be applied so that there is no net movement of solvent across the membrane. 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 hydrophobicmolecules 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 turgorpressure of a cell is largely maintained by osmosis across the cell membrane between the cell interior and its relatively hypotonic environment.