Cell Membrane and Cell Transport

Front

Homeostasis

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Maintaining a stable internal environment

(for example, maintaining water balance in your cells or consistent body temperature)

Front

cell membrane (AKA, the plasma membrane)

Back

1. Made of two phospholipid layers, called the phospholipid bilayer

Controls what enters and exits the cell

Front

phospholipid

Back

The type of lipid that makes up the majority of the cell membrane. Consists of a polar (hydrophilic) head and two nonpolar (hydrophobic) tails.

Front

selectively permeable

Back

Describes the cell membrane; it selects what it will allow in or out

(some molecules, such as small nonpolar ones, will cross easily while larger, polar molecules will need help)

Front

concentration

Back

the amount of a substance dissolved (solute) in another substance (solvent)

the more "stuff" (solute), the more concentrated; the less "stuff", the more diluted/less concentrated

Front

concentration gradient

Back

the difference in concentration between two areas, such as between the inside and outside of the cell

Front

passive transport

Back

movement of molecules from high to low concentration that does NOT require energy

Front

diffusion

Back

a type of passive transport that moves small, nonpolar molecules down the concentration gradient (from high to low concentration)

Front

facilitated diffusion

Back

a type of passive transport where larger, polar molecules are moved down the concentration gradient using membrane proteins

Front

osmosis

Back

a type of passive transport that moves WATER across a semi-permeable membrane down the concentration gradient