What Could Affect the Rate of Diffusion of a Molecule Through a Membrane?

What Could Affect the Rate of Diffusion of a Molecule Through a Membrane
••• artisteer/iStock/GettyImages

Diffusion occurs whenever random molecular motion causes molecules to move and mix together. This random motion is powered by the heat energy present in the surrounding environment. The rate of diffusion -- which causes molecules to naturally move from high concentration to low concentration in search of uniform distribution or "equilibrium" -- depends on several factors.

Molecules in Motion

Six physical and environmental conditions govern the rate of diffusion. Four of these are applicable to all types of diffusion, and two apply only to diffusion through a membrane. The mass of molecules is a major factor, because smaller molecules have higher random velocity for a given ambient temperature, and higher random velocities correspond to faster diffusion. Similarly, ambient temperature affects diffusion because higher temperatures lead to higher random velocities. Diffusing molecules flow from high concentration to low concentration, and the rate of diffusion increases when the difference in concentration is greater. The rate of diffusion decreases, however, when molecules must travel a longer distance in their search for equilibrium.

The two factors that are particular to diffusion through a membrane are surface area and permeability. A membrane with smaller surface area or lower permeability will impede molecular movement and thus lead to slower diffusion.

Related Articles

Four Things That Affect Rate of Diffusion
How Does Diffusion Work?
What Are Three Things That Determine if a Molecule...
How to Calculate Diffusion Rate
Definition of Molecular Bonds
Similarities & Differences Between Osmosis & Diffusion
How to Convert PPH to GPM
Examples of Substances That Use Facilitated Diffusion
List Some Factors That Would Increase the Rate of Diffusion
Why Does Sugar Affect the Freezing Point of Water?
What Is the Difference Between Active & Passive Transport...
How Does the Force of Momentum Affect an Object in...
Chemistry Projects for Diffusion in Liquids
What Are Five Properties of Gases?
Why Does the Boiling Point Increase When the Atomic...
Similarities & Differences of Cubes & Cuboids
How Does Ink Diffuse in Water?
What Are Concentration Gradients in Microbiology?
The Types of Electrophoresis

Dont Go!

We Have More Great Sciencing Articles!