A)
Osmotic pressure is the minimum pressure needed to prevent the inward flow of a pure solvent through a semipermeable membrane.
Turgor pressure, inside the cell, pushes the plasma membrane against the plant cell wall.
Turgor Pressure vs. Osmotic Pressure:
Turgor Pressure
1. Turgor pressure arises in the cell due to osmotic water entry, maintaining plant parts’ original form and size. Maximum turgor pressure is in fully turgid cells.
2. Turgor pressure develops in a closed system.
Osmotic Pressure
1. Osmotic pressure, measured in bars, represents the pressure buildup in a solution separated from water by a semipermeable membrane. It equals a positive osmotic potential.
2. Osmotic pressure can develop in both closed and open systems.
B)
Diffusion vs. Osmosis:
1.
Diffusion: Movement of particles from higher concentration to lower concentration.
Osmosis: Movement of solvent molecules from lower solute concentration to higher solute concentration through a semipermeable membrane.
2. Nature:
Diffusion:General movement of particles.
Osmosis:Specific to solvent molecules.
3. Membrane Involvement:
Diffusion: Can occur without a membrane.
Osmosis: Requires a semipermeable membrane.
4. Direction of Movement:
Diffusion: Along concentration gradient.
Osmosis: Across a semipermeable membrane.
5. Role in Living Systems:
Diffusion: General role in substance movement within cells.
Osmosis: Specifically describes water movement across cell membranes.
6. Examples:
Diffusion: Perfume spreading in the air.
Osmosis: Water uptake by plant roots.
In essence, diffusion involves the movement of particles, while osmosis specifically pertains to the movement of water molecules through a semipermeable membrane.