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AP bio Chapter 7

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integral protein
inserted into phospholipid bilayer
peripheral
not embedded into phospholipid bilayer, but are attached to the membrane surface
how do integrals stick to the membrane?
solubility of amino acid
where are carbohydrates found in the membrane?
only in outer surface
oligosaccharides
form glycophospholipids and glcoproteins; recognize self vs. others
passive transport
3 types: 1. diffusion 2. osmosis 3. facilitated diffusion; does not require energy
diffusion
net movement of atoms, ions, or molecules downa concentration gradient
equilibrium
when the concentration is equal on both sides; no net movement of materials
factors that efffect difusion
1. concentration 2. temp. 3. pressure 4. particle size 5. mixing
osmosis
diffusion of water
isotonic solution
cell and water are equal in concentration; no change in cell size
hypotonic solution
cells water is lower than outside water; water moves into cell; cells swells, may burst
hypertonic solution
cells water is higher than outside water; water moves out of cell; cell shrinks
osmoregulation
regulation of solute concentrations and water balance by a cell or organism
turgid
swollen; only in plant cells
flaccid
limp; lacking stiffness; on in plant cells
plasmolysis
cytoplasm shrivels and plasma membrane pulls away from the cell wall, occurs when cell loses water in hypertonic solution; only in plant cells
facilitated diffusion
uses transport protein to help materials through the cell membrane, no ATP
carrier protein
proteins that transport specific substances across a biological membrane; molecule specific; undergoes change in shape;
ion channel
Protein channel in a cell membrane that allows passage of a specific ion down its concentration gradient.
gated channel
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
3 types of active transport
1. carrier mediated 2. endocytosis 3. exocytosis
carrier mediated transport
active transport of materials into cells AGAINST the concentration gradient, high to low
sodium potassium pump
moves sodium out of cell and potassium in, 3 sodium, 2 potassium; in animal cells; creates a positive charge on outside and negative inside
cotransport
movement of H+ that allows other material to be transported into the cell as the H+ diffuses back across the cell membrane
endocytosis
process by which a cell surrounds and engulfs substances; pinches off from the cell membrane and becomes a membrane-bound organelle; 3 types: pinocytosis, phagocytosis, receptor-mediated
vesicle
membrane bound organelle
pinocytosis
endocytosis involving the transport of solutes or fluids
phagocytosis
endocytosis involving the transport of large particles or whole cells
receptor-mediated
movement of specific molecules into a cell by binding to specifc cites on the cell even though they may not be highly concentrated in teh extra-cellular fluid
ligand
molecules that bind
exocytosis
process by which vessicles inside a cell fuses with the cell membrane and release its contents to the external environment, how proteins exit cells