What is Facilitated Diffusion?
Active and passive transport are the 2 main transport mechanisms mediating commination between an environment and a plant in which organizing tissues are directly interconnected and respond to environmental changes directly. Lack of central organizing unit and control mechanism in lower organisms such as plants directly interact with the environment at cellular or tissue level massively depends on Active and Passive transports. In plants water is a main element of circulation and in assimilation of CO2 to sucrose; absorbed in root hairs Passive uptake of water – Diffusion and facilitated diffusion.
Facilitated diffusion – a modified mechanism of diffusion; involves membrane transporters to allow water and other molecules on difference between concentration and electrochemical gradient. In 1930, passive transport of water in cells were experimented by artificially creating a cell to understand the better transport mechanism; resulted in efficient flow of water and minerals through membrane transporters in facilitated diffusion rather than through lipid bilayers as in simple diffusion. Facilitated diffusion is bi – directional depending upon either concentration gradient and electrochemical gradient. At equilibrium, the rate of transport of net molecules of water or other elements is minimal or null.
Schematic Representation of Facilitated Diffusion
Facilitated Diffusion Characteristic
1. Specificity: Transmembrane proteins are frequent in between sets of lipid bilayer. Molecules of transport are permitted in specific transporter molecules depending upon the molecule that enters a cell.
2. Passive Nature: Transport through the channels does not require the conversion of ATP into ADP or AMP to power the movement of molecules from higher concentration to lower concentration.
3. Saturation Kinetics: Apart from the specificity and passive transport; driving force of the net movement of molecules depends on the concentration or the net number of molecules present between external and internal environment of cell.
Facilitated Diffusion Citations