What is the Difference Between Osmosis and Diffusion
The movement of molecules takes place by various processes such as diffusion and osmosis. As we know, Diffusion is the movement of particles from a region of higher concentration to a region of lower concentration until the equilibrium is achieved. And Osmosis is the process of the passage of solvent molecules from a region of higher concentration to a region of lower concentration via a semi-permeable membrane. These two are the major force driving the movement of particles across membranes in the medium. Let's see the differences between diffusion and osmosis in detail in this article.
Diffusion
Diffusion is the movement of particles from a high-concentration area to a low-concentration area. The overall effect of diffusion is to balance the concentration across the medium.
The pressure created by the diffusing particles is known as diffusion pressure (DP), and it is directly proportional to the number or concentration of the diffusing particles. The molecules transition from higher DP to lower DP.
The Characteristics of Diffusion -
The movement of one substance does not affect the diffusion of another.
It is essential to plants because it is the only way for gaseous movement within the plant body.
The process is slow and does not involve any living systems. Diffusion occurs frequently in gases and liquids. Diffusion in solids is rare. Diffusion rates are influenced by factors such as membrane permeability, concentration gradient, pressure, and temperature.
Lipids are the major constituent of cell membranes. Therefore, it influences the solubility of substances in cell membranes. Lipid-soluble substances diffuse faster through the membrane. A substance that is hydrophilic in nature has difficulty passing through the membrane; its movement must be aided.
Example of Diffusion
Diffusion examples includes perfume filling an entire room and the movement of small molecules across a cell membrane.
Adding a drop of food coloring to water is one of the simplest demonstrations of diffusion.
Although other transport processes occur, diffusion is the most important.
Osmosis
The cell wall and cell membrane surround the plant cell. The cell wall is permeable to water and other substances in solution and thus does not act as a barrier to movement. The cell membrane and tonoplast of plant cells work together to control the movement of molecules in and out of the cell.
Osmosis is the passage of solvent molecules through a semi-permeable membrane from a region of higher concentration to a region of lower concentration.
Osmosis occurs naturally as a result of a driving force.
Factors Affecting Osmosis are -
The concentration of dissolved solutes in a solution
Pressure gradient
The hydrostatic pressure developed in a solution when it is separated from pure solvent by a semi-permeable membrane in a rigid vessel is referred to as osmotic pressure. It can only grow in a confined system.
Osmotic pressure has the same numerical value as osmotic potential but has a positive sign. The presence of solute particles reduces the free energy of water in a system, resulting in osmotic potential. Osmotic potential exists whether the solution is in a confined or open system. The osmotic potential value is negative.
Examples of Osmosis
Examples include red blood cells swelling up when exposed to fresh water and plant root hairs absorbing water. Soak gummy candies in water to see an easy demonstration of osmosis. The candies' gel acts as a semipermeable membrane.
Similarities Between Osmosis and Diffusion
The concentration of two solutions is equalised by osmosis and diffusion.
Diffusion and osmosis are both passive transport processes, which means they do not require any additional energy input to occur.
Particles move from a high concentration area to a low concentration area in both diffusion and osmosis.
Difference between Diffusion and Osmosis
Despite some similarities, the diffusion and osmosis processes differ in several ways.
List of Differences Between Osmosis and Diffusion
Key Points to Remember
By applying the additional hydrostatic pressure to the solution side of the membrane, the osmosis process can be reversed. This is known as reverse osmosis, and it increases the solvent molecules' tendency to escape.
Diffusion is associated with the random movement of solute particles, whereas osmosis is associated with the only solvent moving in a single direction.
FAQs on Difference Between Diffusion and Osmosis
1. What is osmotic pressure?
When a semipermeable membrane separates a solution from pure water, osmotic pressure is defined as the pressure that must be applied to the solution side to stop fluid movement.
2. Explain whether osmosis is a form of active or passive transport.
The osmosis is a type of diffusion which is a passive transport process. It does not require energy for the transport of solvent from high concentration to lower concentration.
3. Define water potential.
Water potential is the difference between free energy of water molecules in a pure solvent and free energy of water molecules in a solution. The movment of water occurs from high water potential to low water potential.
