Question

Compare and Contrast Diffusion and Osmosis Diffusion Osmosis Is a gradient needed? Direction of movement in relation to the solute) Is a membrane required? Source of energy for movement What is moved

Answer 1

	Diffusion	Osmosis
Is a gradient needed	A gradient is required	A gradient is required
Direction of movement( In relation to solute)	Molecules move from higher molecules of solute to lower concentration of solute	Molecules move from lower molecules of solute to higher concentration of solute
Is a membrane required ?	Do not require a semi permeable membrane	It occures only under a semi-permeable membrane.
Source of energy for movement	Simple diffusion does not require energy (based on concentration difference) facilitated diffusion requires a source of ATP	Osmosis is a selective diffusion process driven by the internal energy of the solvent molecules(The driving force of the solvent shift is the concentration difference of solutes in the solutions separated by the semipermeable membrane)
What is moved ?	It involves the movement of solute molecules.	It involves the movement of solvent molecules.

• Osmosis: Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution. The solvent moves to dilute the concentrated solution and equalize the concentration on both sides of the membrane.
• Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. The overall effect is to equalize concentration throughout the medium.

Diffusion	Osmosis
Any type of substance moves from an area of highest energy or concentration to a region of lowest energy or concentration.	Only water or another solvent moves from a region of high energy or concentration to a region of lower energy or concentration.
Diffusion can occur in any medium, whether it is liquid, solid, or gas.	Osmosis occurs only in a liquid medium.
Diffusion does not require a semipermeable membrane.	Osmosis requires a semipermeable membrane.
The concentration of the diffusion substance equalizes to fill the available space.	The concentration of the solvent does not become equal on both sides of the membrane.
Hydrostatic pressure and turgor pressure do not normally apply to diffusion.	Hydrostatic pressure and turgor pressure oppose osmosis.
Diffusion does not depend on solute potential, pressure potential, or water potential.	Osmosis depends on solute potential.
Diffusion mainly depends on the presence of other particles.	Osmosis mainly depends on the number of solute particles dissolved in the solvent.
Diffusion is a passive process.	Osmosis is a passive process.
The movement in diffusion is to equalize concentration (energy) throughout the system.	The movement in osmosis seeks to equalize solvent concentration, although it does not achieve this.