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The process of osmosis over a semipermeable membrane.The blue dots represent particles driving the osmotic gradient. Osmosis (/ ɒ z ˈ m oʊ s ɪ s /, US also / ɒ s-/) [1] is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential ...
An increase of turgor pressure causes expansion of cells and extension of apical cells, pollen tubes, and other plant structures such as root tips. Cell expansion and an increase in turgor pressure is due to inward diffusion of water into the cell, and turgor pressure increases due to the increasing volume of vacuolar sap. A growing root cell's ...
An example of an inventory that assesses knowledge of such concepts is an instrument developed by Odom and Barrow (1995) to evaluate understanding of diffusion and osmosis. [26] In addition, there are non-multiple choice conceptual instruments, such as the essay-based approach [ 13 ] and the essay and oral exams concept to measure student ...
Osmosis in a U-shaped tube. Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. [1] It is also defined as the measure of the tendency of a solution to take in its pure solvent by osmosis.
Dialysis tubing is also frequently used as a teaching aid to demonstrate the principles of diffusion, osmosis, Brownian motion and the movement of molecules across a restrictive membrane. For the principles and usage of dialysis in a research setting, see Dialysis (chemistry).
The word diffusion derives from the Latin word, diffundere, which means "to spread out". A distinguishing feature of diffusion is that it depends on particle random walk, and results in mixing or mass transport without requiring directed bulk motion. Bulk motion, or bulk flow, is the characteristic of advection. [1]
Multicomponent diffusion is diffusion in mixtures, and diffusiophoresis is the special case where we are interested in the movement of one species that is usually a colloidal particle, in a gradient of a much smaller species, such as dissolved salt such as sodium chloride in water. or a miscible liquid, such as ethanol in water.
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.