Comparison Between Simple And Facilitated Diffusion

There are two types of diffusion processes, which are distinguished by the presence or absence of facilitator molecules: 

• Simple diffusion 
• Facilitated diffusion. 

Simple diffusion is the most common type of diffusion process.

Simple diffusion is defined as diffusion that happens without the assistance of intermediary molecules such as channel proteins or carrier molecules. 

Facilitated diffusion is the process of spontaneous movement of molecules or ions across a cell’s membrane that is facilitated by the presence of particular transmembrane proteins.

Differentiating  Simple and Facilitated Diffusion

Definition

Simple Diffusion: Simple diffusion is a type of diffusion in which a particle goes from a higher concentration to a lower concentration without the assistance of another particle.

It is important to understand the concept of Facilitated Diffusion, which is the movement of substances across a biological membrane through a concentration gradient with the help of an extracellular carrier molecule.

Occurrence

Simple Diffusion: 

Simple diffusion occurs within the phospholipid bilayer.

Facilitated Diffusion: 

Facilitated diffusion is caused by the presence of transmembrane proteins in the body.

Transported Molecules

Simply said, simple diffusion transfers tiny, non-polar particles from one location to another.

Diffusion with Facilitation: Diffusion with facilitation is used to transport big or polar particles.

Facilitator Molecules

Simple Diffusion: Simple diffusion occurs directly through the cell membrane and is the simplest type of diffusion.

Diffusion with Facilitation: Diffusion with facilitation is achieved through the use of particular facilitator molecules known as transmembrane integral proteins.

Rate Of Diffusion

Simple Diffusion: The rate of Simple diffusion is directly related to the concentration gradient across a membrane, as well as the solute molecule’s membrane permeability.

Facilitated Diffusion: The rate of facilitated diffusion is determined by the kinetics of the carrier-mediated transport.

Low concentration Gradient

Simple Diffusion: The rate of simple diffusion is low at low solute concentrations because the solute concentration is low.

Facilitated Diffusion: When compared to simple diffusion, the rate of facilitated diffusion is much higher at low solute concentrations than that of simple diffusion.

Examples

Simply said, diffusion is the movement of gases across a membrane, such as the respiratory membrane, or the movement of molecules from the blood to the cells, such as the interstitial fluid.

Facilitated diffusion can be seen in the counter-transport of chloride and bicarbonate in renal tubular cells, as well as the cotransport of sodium with carbohydrates such as glucose, galactose, and fructose, as well as the cotransport of amino acids.

A comparison of simple and facilitated diffusion –

It is important to note that the primary difference between simple diffusion and facilitated diffusion is that simple diffusion is an unfacilitated type of diffusion in which particles move from one concentration point across another, while facilitated diffusion is the transport of substances across a biological membrane by way of a concentration gradient and the use of a carrier molecule.

There is both simple and facilitated diffusion occurring down the concentration gradient, which is occurring from a high concentration of molecules to a low concentration of molecules.

Both methods of transport do not necessitate the use of energy to carry molecules.

At the equilibrated condition, the net movement of molecules on either side of the cell membrane is equal to zero on both sides.

Simple diffusion and facilitated diffusion are two forms of passive transport mechanisms in which molecules are transported across the cell membrane by the cell membrane.

In order to equalise the concentration of molecules, it makes advantage of natural entropy to shift molecules from a higher concentration to a lower concentration. The transfer of molecules is thus accomplished without the usage of any ATP energy. 

Conclusion

Molecular transportation across the cell membrane can be accomplished through simple diffusion and facilitated diffusion, both of which are passive transport techniques. Diffusion occurs as a result of a concentration gradient in both simple and facilitated diffusion. The primary distinction between simple diffusion and facilitated diffusion is in the process by which molecules are transported over the cell membrane. Simple diffusion is the direct transport of molecules across the cell membrane that is allowed by the cell membrane. Facilitated diffusion, on the other hand, occurs through the action of transmembrane proteins such as carrier proteins, channel proteins, and aquaporins. Simple diffusion is used to transport nonpolar molecules of small size. Large and polar molecules are moved through the environment by facilitated diffusion. At the equilibrated condition, the net movement of molecules on either side of the cell membrane is equal to zero on both sides.