aos 1 Flashcards
chapter 3
plasma membrane
the phospholipid bilayer and embedded proteins which separate the intracellular environment from the extracellular environment. Also known as cell membrane
cytosol
the aqueous fluid that surrounds the organelles inside a cell
passive transport
the movement of molecules through a semipermeable membrane and down the concentration gradient, without an input of energy
active transport
movement of molecules across a semipermeable membrane that requires energy
diffusion
the passive movement of molecules from areas of
high concentration to areas of low concentration (down the concentration gradient)
concentration gradient
the difference in solute concentration between two adjacent areas
solute
a substance dissolved in the solvent
solvent
liquid in which a solute is dissolved, forming a solution
nonpolar
describes a molecule without a clearly positive or negative end. These tend to
be hydrophobic
polar
describes a molecule with both a positive end and a negative end. These tend to be hydrophilic
facilitated diffusion
a type of passive transport where molecules move through a phospholipid bilayer with
the aid of a membrane protein
protein channel
a transmembrane protein pore in a phospholipid bilayer that selectively enables transport of large or polar molecules
carrier protein
a membrane protein that undergoes conformational change to transport molecules across a membrane
osmosis
the passive transport of a solvent (typically water) through a semipermeable membrane
from a region of low solute (high solvent) to a region of high solute (low solvent)
hypertonic
describes a solution with a higher solute concentration when compared to another solution
