Unit 2: Diffusion Vocab

Solution

What forms when one substance dissolves another.

Concentration

A measurement of how much solute exists within a certain volume of solvent

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Simple diffusion

Diffusion that can happen without assistance (ex. by proteins)

Facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

Osmosis

Diffusion of water molecules across a selectively permeable membrane

Semipermeable or selectively permeable membrane

A membrane that allows some molecules to pass through but does not allow other molecules to pass through.

Equilibrium

A state of balance

Phospholipids

Makes up cell membranes; has a hydrophilic head and hydrophobic tail

Hydrophilic

Attracted to water

Hydrophobic

Water 'fearing'/repelling

Bilayer

A double layer (membrane is a phospholipid bilayer)

Concentration gradient

Difference in the concentration of a substance from one location to another

Channel protein

A membrane protein, specifically a transport protein, that has a channel that certain molecules use as a tunnel through the membrane

Cell membrane

Thin, flexible barrier around a cell; regulates what enters and leaves the cell

Molarity

Unit of solute concentration, referring to the amount of solute per liter of solution. (ex. 0.2 M)