If you like us, please share us on social media.
The latest UCD Hyperlibrary newsletter is now complete, check it out.

BioWiki: The Dynamic Biology Hypertext > Biochemistry > Lipids > Dynamics of Membrane Lipids > Membrane Permeability

Membrane Permeability

Table of Contents

Another indicator of membrane dynamics is the measured permeability coefficient of ions and molecules across the bilayer. (see Passive and Facilitated Diffusion). Permeabilities are correlated to the partition coefficient of the molecule or ion in organic solvents. If the molecule readily dissolves in a nonpolar solvent, it is more likely to pass through the hydrophobic barrier of the membrane. Obviously the size of the molecule would play a part as well. Hence charged ions like Na+ and K+ have low permeabilities. Cl- has a higher permeability, since the charge density on the larger Cl anion is smaller. Water has a surprisingly high permeability although it is polar. It is small and can enter down deep into the head group region through sequential H-bonding which must assist its transfer across the membrane.

Figure: Permeability of liposome bilayers


Many different probes have been developed to study membrane structure and dynamics. Many of them are fluorescent. The diagram below, taken from the Molecular Probe's catalog, gives examples.

You must to post a comment.
Last modified
00:35, 21 Nov 2013


This page has no custom tags.


This page has no classifications.

The Core



This material is based upon work supported by the National Science Foundation under Grant Numbers 1525057, and 1413739.

Creative Commons License UC Davis GeoWiki by University of California, Davis is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. Permissions beyond the scope of this license may be available at copyright@ucdavis.edu. Terms of Use