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:8/20/2014)... 20, 2014 /CNW/ -  Issue Serious ... quickly become life threatening for some children.    ... million Canadians have food allergies and this number may be ... children are estimated to have food allergies.  ... irritations and hives to breathing difficulties and loss of consciousness. ...
(Date:8/20/2014)... in this image of the Para and Mato Grosso ... likely intentionally set in order to deforest the land. ... of trees where the land is thereafter converted to ... forestland to farms, ranches, or urban use. The herringbone-patterned ... Amazon Rainforest in the middle of the image are ...
(Date:8/20/2014)... Bay Area Lyme Foundation, which aims to make Lyme ... new research published in an upcoming issue of the ... . The findings show that ticks that carry ... year, making the threat of Lyme disease year-round. The ... Public Health (CDPH) Vector-borne Disease Section and University of ...
Breaking Biology News(10 mins):Information Update - Allergens and food safety at school - What's in your child's lunch? 2Information Update - Allergens and food safety at school - What's in your child's lunch? 3Lyme disease risk is year-round in Northwest California, according to new study 2Lyme disease risk is year-round in Northwest California, according to new study 3
... compounds beginning in early adulthood may delay the onset ... Wake Forest University School of Medicine and other centers ... the Endocrine Society, in San Diego. , Suppression of ... decrease cancer risk in those individuals at high risk ...
... University chemists have employed a computer simulation whose ... transcription process. The study, funded by the National ... issue of the Proceedings of the National Academy ... chromatin--a chromosome's substance consisting of histone proteins and ...
... can create tiny sensors with abilities to detect odors ... Pennsylvania and Monell Chemical Sciences Center. Their findings are ... Letters, a publication of the American Chemical Society. , ... detect molecules on the order of one part per ...
Cached Biology News:Suppressing growth hormone in early adulthood may prevent cancer 2Researchers Create DNA-Based Sensors for Nano-Tongues and Nano-Noses 2
Other biology definitionOther Tags