Simple diffusion is the passive movement of solute from a high concentration to a lower concentration until the concentration of the solute is uniform throughout and reaches equilibrium.

During diffusion, when the concentration of molecules on both sides of a membrane is the same, the molecules will continue to move across the membrane in both directions. 2. An animal cell that is surrounded by fresh water will burst because the osmotic pressure causes water to move into the cell.

Pump action is an example of active transport. Channels, in contrast, enable ions to flow rapidly through membranes in a downhill direction. Channel action illustrates passive transport, or facilitated diffusion. Pumps are energy transducers in that they convert one form of free energy into another.

These include: Temperature of the system, Size of the molecule, Other factors include any charges on the molecule (positive or negative) and the nature of the material that the molecules are moving through. As the active transport utilises energy, so it normally occurs faster than passive transport.

In simple diffusion, the molecules can pass only in the direction of concentration gradient. In facilitated diffusion, the molecules can pass both in direction and opposite of the concentration gradient. Simple diffusion permits the passage of only small and nonpolar molecules across the plasma membrane.

Passive diffusion follows a concentration gradient, which relates to the transport of molecules from a location of higher concentration to a site of lower concentration without using chemical energy according to Fick’s law of diffusion.

Facilitated diffusion is a type of passive transport. Even though facilitated diffusion involves transport proteins, it is still passive transport because the solute is moving down the concentration gradient. Small nonpolar molecules can easily diffuse across the cell membrane.

Certain channel proteins are involved in facilitated diffusion, which results in the formation of particular pores for the movement of molecules. The exchange of gases between lungs and blood, the mixing of gases in the atmosphere, and the absorption of nutrients by bacteria are some examples of simple diffusion.

The factor that does not affect the rate of diffusion are the electrical charges of the diffusion particles. The electrical charges do not participate in such processes.

Example of Simple Diffusion In the cell, examples of molecules that can use simple diffusion to travel in and out of the cell membrane are water, oxygen, carbon dioxide, ethanol and urea. They pass directly through the cell membrane without energy along the concentration gradient.

Several factors affect the rate of diffusion of a solute including the mass of the solute, the temperature of the environment, the solvent density, and the distance traveled.

Simple diffusion is the process by which solutes are moved along a concentration gradient in a solution or across a semipermeable membrane. Water can move along its concentration gradient through a cell membrane in this manner, a form of simple diffusion known as osmosis.