Question

1. describe the characteristics of types of passive transport.

review these concepts

	simple diffusion	osmosis	facilitated diffusion
net movement of molecules	d	e	f
energy requirement	g	h	i

Explanation:

Each type of passive transport has distinct defining features:

1. Simple Diffusion: Small, nonpolar molecules move directly through the phospholipid bilayer down their concentration gradient, no energy needed.
2. Osmosis: A specialized form of passive transport limited to water molecules, moving across a semipermeable membrane to balance solute concentrations, no energy needed.
3. Facilitated Diffusion: Larger or polar molecules use integral membrane proteins (channels/carriers) to move down their concentration gradient, no energy needed.

Answer:

Category	Simple Diffusion	Osmosis	Facilitated Diffusion
Net movement of molecules	D. Down the concentration gradient (high to low)	E. Down the water potential gradient (low solute to high solute concentration)	F. Down the concentration gradient (high to low, via transport proteins)
Energy Requirement	G. No cellular energy (ATP) required	H. No cellular energy (ATP) required	I. No cellular energy (ATP) required