2.15, 2.16. 2.17 Membrane transport

Diffusion

Movement of particles or molecules from an area of high concentration to an area of low concentration

Osmosis

Diffusion of water across a selectively permeable membrane

Selectively pemeable membrane

A membrane that allows certain materials to pass through, but not others

Equilibrium

When there is a relatively equal distribution of a particular molecule

Solute

A substance that is dissolved in a solution

Solvent

The liquid that contains the dissolved solute in a solution.

Active Transport

Movement of molecules against its concentration gradient (from low to high) and requires an input of energy.

Passive

A process that does not require energy from the cell

Down the concentration gradient

Movement of molecules from an area of high concentration to an area of low concentration

Against the concentration gradient

Movement of molecules from an area of low concentration an area of to high concentration

Concentration gradient

A difference in the concentration of a substance from one location to another

Diffusion Distance

The distance that substances must diffuse. The smaller the diffusion distance, the faster the rate of diffusion.

surface area to volume ratio

The ratio of a cell's outside area, compared to its internal volume.

Surface area

The measurement of the outer surface of an object.

Metabolism

All of the chemical reactions that occur within a cell or organism

Dilute

A solution with a small amount of solute

Concentrated

A solution with a large amount of solute