cell membrane structure and transport

for ib bio

phospholipid

two hydrophobic fatty acid tails bonded to a hydrophobic phosphate head

the tails face…

eachother

particles that CAN NOT pass directly through the phospholipid bilayer

large particles and hydrophillic, charged particles

particles that CAN pass directly through the phsospholipid bilayer

hydrophobic (uncharged) particles

passive transport

simple diffusion, osmosis, facilitated diffusion

active transport

requires atp and proton/protein pumps

integral proteins

penetrate into the center, possibly to the other side of the membrane; can be glycoproteins, channels, or protein pumps

peripheral proteins

temporarily attach to one side of the cell membrane; can be receptors and enzymes

osmosis

passive; water molecules from low solute to high solute (high H2O to low H2O) through a semi-permeable membrane

aquaphorins

integral channel proteins that rapidly transport water through membranes through facilitated diffusion; in the kidneys

facilitated diffusion

passive transport; charged particles enter and exit the cell through protein channels

channel proteins

allows facilitated diffusion to happen in response to a stimulus

active transport

movement of particles from high to low concentration using protein pumps and ATP

ATP

adenosine triphoshate

breaking ATP bonds

releases energy for active transport, forms an inorganic phosphate

Na+/K+ pump, endocytosis (phagocytosis/pinocytosis), and exocytosis

active transport

hypertonic solution

higher concentration of solute compared to another solution

hypotonic solution

lower concentration compared to another solution

isotonic solution

same concentration of solutes

water

universal solvent

crenation

loss of water from an animal cell (hypertonic solution)

cytolysis

bursting of an animal cell (hypotonic solution)

contractile vacuole

removes excess water to prevent cytolysis

osmoregulation

regulates osmotic pressure (contractile vacuole, kidneys)

plasmolysis

in a hypertonic solution when the plasma membrane and cytoplasm shrink and detach from cell wall

turgid

the vacuoule pushes cytoplasm and plasma membrane against the wall and creates turgor pressure, which is equal to the pressure exerted by the cell wall

flaccid

wilted plant