Facilitated diffusion is a form of passive transport that utilizes transport proteins. These transport proteins are embedded within cell membranes, serving as figurative highways for molecules to get in and out of the cell.Continue Reading
Facilitated diffusion is also sometimes called carrier-mediated transport. Like conventional diffusion, facilitated diffusion requires a concentration gradient, a region of high concentration of a chemical species connected by a transport medium to a region of lower concentration. The species in both regions move randomly, but because the higher concentration region has more of the species, there is net migration from the higher concentration region to the low one.
The transport proteins in facilitated diffusion act as a specialized transport medium, allowing certain chemical species to move more efficiently from the high concentration region to the low one. This process is vital to life, as it enables cells to obtain essential nutrients including lipids, simple sugars, water and oxygen.
The rate at which species move from the high concentration region is a complex function of the difference in concentration between the two regions, the thermal and chemical energy available to the species, species-carrier interactions and absolute temperature. All passive transport processes generally proceed faster as temperature increases.Learn more about Cells
There are four different types of passive transport: diffusion, facilitated diffusion, filtration and osmosis. Diffusion is the movement of substances from an area of high concentration to an area with lower concentration. The difference of concentration between these two areas is called concentration gradient.Full Answer >
Facilitated diffusion uses carrier proteins to pump substances across the cell membrane that would not normally be able to cross the membrane on their own. These substances include sodium and chloride ions and molecules such as glucose.Full Answer >
The cellular structure responsible for packaging proteins for transport out of the cell is the Golgi apparatus. This structure was identified by Italian scientist Camillo Golgi in 1897 and officially named after him a year later.Full Answer >
Examples of facilitated diffusion are the passing of K+ ions through a membrane with an aid of a potassium transport protein and the passing of glucose and amino acids with the aid of proteins called permeases. Retinol binding protein acts as a water-soluble carrier for retinol and fatty acids.Full Answer >