The diffusion of water molecules from high to low concentration.
They let some substances pass through them, but not others.
SemiPermeable Membrane
The movement of dissolved molecules into or out of a cell through the cell membrane, from low to high concentration (up the gradient) . Requires ATP.
Active Transport
Effected by temperature, steepness of the gradient, size of the solute and electric or pressure gradients.
Diffusion Rate
The difference between the concentration inside and outside of the cell.
Concentration Gradient
They pick up specific molecules and take them through the cell membrane against the concentration gradient.
Carrier proteins
The semipermeable membrane surrounding the cytoplasm of a cell.
Cell membrane
A dilute solution contains a ____ ____________of water molecules.
High concentration
A concentrated solution contains a ____ _____________of water molecules.
Low concentration
The type of transport that requires no ATP, goes from high to low concentration (down the gradient)
Passive Transport