Navigation Links
Facilitated diffusion


Facilitated diffusion (facilitated transport) is a process of passive transport (diffusion) via which molecules diffuse across membranes, with the help of transport proteins (mediated transport).

Small uncharged molecules can easily diffuse across cell membranes. However, due to the hydrophobic nature of the lipids that make up cell membranes, water-soluble molecules and ions cannot do so; instead, they are helped across by transport proteins. The transport protein involved is intrinsic, that is, it completely spans the membrane. It also has a binding site for the specific molecule (e.g., glucose) or ion to be transported. After binding the molecule, the protein changes shape and carries the molecule across the membrane, where it is released. The protein then returns to its original shape, to wait for more molecules to transport.

In contrast to active transport, facilitated diffusion does not require energy and carries molecules or ions down a concentration gradient.


'"/>


(Date:8/21/2014)... in near darkness use a previously unknown process for ... team led by a Penn State University scientist has ... aimed at improving plant growth, harvesting energy from the ... on Lake Erie and other lakes worldwide. A paper ... Science Express edition of the journal Science ...
(Date:8/21/2014)... fungus linked to dandruff, eczema and other itchy, flaky ... further global reachesincluding Hawaiian coral reefs and the extreme ... A review in the scientific journal PLOS Pathogens ... fungi of the genus Malassezia in light ... from around the world. , University of Hawai,i at ...
(Date:8/21/2014)... food intake, health and quality of life of older ... at the University of Waterloo receiving close to $1.5 ... Research (CIHR). , Professor Heather Keller, of the ... Schlegel research chair in nutrition and aging, will receive ... living in long-term care homes are poorly nourished. The ...
Breaking Biology News(10 mins):Hot-spring bacteria reveal ability to use far-red light for photosynthesis 2Hot-spring bacteria reveal ability to use far-red light for photosynthesis 3From dandruff to deep sea vents, an ecologically hyper-diverse fungus 2Grants will fund landmark aging research at Waterloo 2
... Gulf War Illness (GWI)the chronic health condition that affects about ... to be the result of several factors, which differed in ... war, according to a Baylor University study. , ... , the study investigated links between GWI and veterans, locations ...
... person or set of identical twins. That makes them ... to international travel. But what happens when the tips ... ridges? It,s not the premise for a ... adermatoglyphia. It,s also known as "Immigration Delay Disease," because ...
... milk, a secretion from the crops of parent birds, is ... in flamingos and male emperor penguins. Essential for the growth ... produced by both parents from fluid-filled cells lining the crop ... BioMed Central,s open access journal BMC Genomics uses new technology ...
Cached Biology News:Causes of Gulf War Illness are complex and vary by deployment area -- Baylor University study 2Causes of Gulf War Illness are complex and vary by deployment area -- Baylor University study 3Shake hands with the invisible man 2Milking the pigeon: extracting the mechanisms involved 2
Other biology definitionOther Tags