Unit 5

Properties of cells membrane

has bilayer of phospholipids

selectively permible

flexible

Fluid mosaic model

phospholipids constendly moving

made up of many small pieces of phospholipids and proteins

Phospholipids are made of 2 parts

glycerol-head, hydrophilic, polar

fatty acid-tail, hydrophobic, nonpolar

choestrial

allows fuildity

attachment protein

help support membrane and can coordinate external and internal changes

receptor protein

bind signaling molecules and relay messages

channel and active transport proteins

allow specific ions or molecules to enter or exit the cell

active transport proteins use

ATP to function

junction proteins

form intercellular junctions attaching adjacent cells

glycoproteins

ID tags recognized by membrane proteins of other cells

sodium potassium pump are in

nerve cells

aquaporins proteins

diffuse water rapidly into or out of cell

Passive transport

no energy

goes from high to low

active transport

energy is needed

low to high

concentration gradient

difference in the concentration of molecules across a space

equilibrum

concentration of molecules is equal through a space

no concentration gradient

molecules move randomly with no net movement in one direction

3 types of passive transport

simple diffusion

osmosis

facilitated diffusion

factors that affect diffusion

concentration gradient

temperature

size of molecule

change of rate

simple diffusion

molecules move from high to low

down concentration gradient

no energy

osmosis

diffusion of water

high to low concentration

no energy

slowly diffuse across lipid bilayer despite being polar

3 types of osmosis

isotonic

hypotonic

hypertonic

facilitated diffusion

diffusion with help of membrane proteins

high to low

membrane protein

channel, carrier, aquaporins

isotonic solution

a solution where the solute and water concentration is equal to the inside of a cell

equal salt

after 15 min in isotonic solution

equal rate of water diffusion

size stays same

hypotonic solution

a solution where the water concentration is lower inside the cell

less salt

after 15 min in hypotonic solution

net water movement into cell

cytolysis

cytolysis

cell walls bursting

in hypotonic solutions animal and plant cells

animal cells burst

plant cells increase in osmotic and turgur pressure

osmotic pressure

water pressure in cell

turgur pressure

membrane to wall pressure

hypertonic solution

a solution where the water concentration is lower of that inside of the cell

more salt

after 15min in hypertonic solution

cell looses water

shrivel up

can die

plant cells in hypertonic solution

cell membrane pushes everything close exept for cell wall

plasmolysis

cell membrane shrinks with water loss

types of active transport

endocytosis

exocytosis

protein pumps

endocytosis

substances pulled in through membrane

phagocytosis

endocytosis for solid large particles

recpter mediate

binding specific molecules on a cell surface

Exocytosis

substances pushing out through membrane

protein pumps

sodium potassium pump

contractile vacuole

carrier proteins with ATP

paramecium

pumps water out of cell