Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.

water loving; polar

water hating; non-polar

A molecule that makes up biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

property of biological membranes that allows some substances to pass across it while others cannot

model that describes the arrangement and movement of the molecules that make up a cell membrane

the movement of substances across a cell membrane without the use of energy by the cell

the movement of materials through a cell membrane using energy (ATP)

A state of balance where there are equal concentrations on both sides of a membrane

A difference in the concentration of a substance across a semi-permeable membrane

Movement of molecules through the phospholipids from an area of higher concentration to an area of lower concentration; passive transport

Movement of water through the phospholipids and through aquaporins from an area of higher concentration to an area of lower concentration; passive transport

Movement of molecules through the carrier protein channels from an area of higher concentration to an area of lower concentration; passive transport

transport proteins that require energy to move ions against their concentration gradient; type of active transport

release of substances out a cell by the fusion of a vesicle with the membrane; type of active transport

taking in a substance by a cell wrapping its membrane around the material; type of active transport

from high to low concentration

from low to high concentration

span the membrane between the intracellular and extracellular environments; specifically move particles across the membrane

In a solution, the substance in which the solute dissolves; water

A substance that is dissolved in a solvent when making a solution