function of plasma membrane

plasma membrane function

control movement of substances in and out of the cell which is essential for survival

polar molecules

have a slightly positive end and slightly negative end
dissolve in lipids

non

polar molecules

examples of passive transport

simple diffusion
osmosis
facilitated diffusion

examples of active transport

active transport
bulk transport

diffusion

net passive movement of a substance from a region of high concentration to low concentration until equilibrium has been reached

molecules that can diffuse through phospholipid bilayer

hydrophobic/non

factors that impact diffusion rate

size

osmosis

net movement of free water molecules from an are of high water concentration to an area of low water concentration across a semi permeable membrane

tonicity

the ability of a surrounding solution to cause a cell to gain or lose water

isotonic solution

same concentration of water as cytoplasm of cell
no net water movement

hypertonic solution

lower water concentration than cytoplasm of the cell
water moves out of cell and into water

hypotonic solution

higher concentration of water than cytoplasm of the cell
water moves into cell

effects of a cell in isotonic solution

normal (animal)
flaccid (plant)

effect of a cell in hypertonic solution

lysed or burst (animal)

effect of a cell in hypotonic solution

shriveled (animal)
plasmolysed (plant)

facilitated diffusion

new passive movement of hydrophilic or polar substances from an area of high concentration to an area of low concentration across a semi

active transport

net movement of substances into or out of cells against a concentration gradient through carrier proteins (low

how does atp assist in active transport

atp connects to protein through a specific marker allows the molecule to go through the carrier protein

bulk transport

movement of large molecules in and out of the cell through vesicles

endocytosis process

plasma membrane surrounds material
edges of membrane meet
membranes fuse to form vesicle

types of vesicles

phagocytosis

exocytosis process

vesicle with substance travel to plasma membrane
membrane of vesicle fuses with plasma membrane
substance secreted