Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Protein Diffusion in the Membrane

Protein Diffusion in the Membrane

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...

Diffusion

Diffusion

Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...

Diffusion

Diffusion

Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. For example, take the diffusion of substances through the air. When someone opens a perfume bottle in a room filled with people, the perfume is at its highest concentration in the bottle and is at its lowest at the edges of the room. The perfume vapor will diffuse, or spread away, from the...

Passive Diffusion: Overview and Kinetics

Passive Diffusion: Overview and Kinetics

Passive diffusion is a critical process that allows small lipophilic drugs to cross the cell membrane along a concentration gradient. This mechanism's efficiency depends on four primary factors: the membrane's surface area, the drug's lipid-water partition coefficient, the concentration gradient, and the membrane's thickness.
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...

Drug Absorption Mechanism: Passive Membrane Transport

Drug Absorption Mechanism: Passive Membrane Transport

Passive transport is a method of drug absorption where small, lipid-soluble drugs can move across the cell membrane. This movement happens along the concentration gradient, which is a natural flow from higher to lower concentration areas. The speed at which the drug moves is directly related to its lipid–water partition coefficient. This means that the more a drug dissolves in lipids, the faster it diffuses or spreads throughout the body. It is important to note that most drugs are either weak...

Asymmetric Lipid Bilayer

Asymmetric Lipid Bilayer

Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Communication: Critical dynamics and nuclear relaxation in lipid bilayers.

The Journal of chemical physics·2011

Same author

Composition fluctuations, correlated response, and protein solvation in membranes.

The Journal of chemical physics·2010

Same author

Adventures in physical chemistry.

Annual review of biophysics·2010

Same author

Nuclear relaxation and critical fluctuations in membranes containing cholesterol.

The Journal of chemical physics·2009

Same author

Molecular motion at the critical point in lipid membranes.

Biophysical journal·2008

Same author

Composition fluctuations, chemical exchange, and nuclear relaxation in membranes containing cholesterol.

The Journal of chemical physics·2007

Search research articles

Related Experiment Video

Updated: May 16, 2026

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes

Published on: July 19, 2022

Single molecule diffusion in critical lipid bilayers.

Harden McConnell¹

¹Department of Chemistry, Stanford University, Stanford, California 94305, USA. harden@stanford.edu

The Journal of Chemical Physics

|December 13, 2012

Summary

Single molecule diffusion in lipid mixtures exhibits biphasic behavior near critical points. This study reveals a switch from fast to slow diffusion, offering experimental detection possibilities for critical phenomena.

Area of Science:

Physical Chemistry
Soft Matter Physics
Materials Science

Background:

Understanding molecular diffusion in complex fluids like lipid mixtures is crucial.
Near miscibility critical points, fluid properties exhibit significant fluctuations.
Single molecule diffusion can probe local dynamics and phase behavior.

Purpose of the Study:

To investigate time-dependent single molecule diffusion coefficients.
To analyze diffusion in lipid mixtures close to a miscibility critical point.
To connect probe molecule diffusion to theoretical composition diffusion coefficients.

Main Methods:

Utilizing theoretical wave vector dependent composition diffusion coefficients.
Performing calculations based on existing theoretical frameworks.

More Related Videos

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Published on: April 23, 2017

Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer

Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer

Published on: October 15, 2015

Related Experiment Videos

Last Updated: May 16, 2026

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes

Published on: July 19, 2022

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Published on: April 23, 2017

Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer

Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer

Published on: October 15, 2015

Analyzing the time-dependent diffusion of a fluorescent probe molecule.

Main Results:

Observed striking biphasic time-dependent diffusion for the probe molecule.
Identified a switch from faster to slower diffusion at a specific time scale (approximately πξ(2)/D).
Suggested that probe diffusion reflects time-dependent composition diffusion near the critical point.

Conclusions:

The diffusion of a probe molecule is influenced by critical composition fluctuations.
Biphasic time-dependent diffusion is a key characteristic near miscibility critical points.
This phenomenon is predicted to be experimentally detectable.