Biology Unit 2: Cell Transport

passive transport: high to low (doesn’t require energy)

simple diffusion: through lipid bilayer

facilitated diffusion: through protein channels

tonicity: because many solutes cannot move back and forth between the cell, water moves back and forth in an attempt to maintain homeostasis

isotonic: solute concentration is equal inside and out

isotonic water movement: both ways (cell size stays the same)

hypertonic: solute concentration is greater outside

hypertonic water movement: out (cell shrinks)

hypotonic: solute concentration is greater inside

hypotonic water movement: in (cell grows)

\ active transport: low to high (requires energy)

endocytosis: substance moved to inside the cell

endocytosis examples: phagocytosis, pinocytosis, white blood cells

exocytosis: substance moved to outside the cell

exocytosis examples: waste, toxic molecules