Cell Membranes ( 5&9) Flashcards
passive transport
energy comes from concentration gradient
active transport
energy comes from breaking ATP
solvent
substance which dissolves another
solute
substance which dissolved within another
equilibrium
identical solute concentrations in all regions
osmosis
net movement of solvent to create equilibrium
diffusion
net movement of solute to create equilibrium
phospholipids
2 fatty acids- NP & hydrophobic
1 phosphate group - P & Hydrophilic
1 way membranes change
layers are fluid
-individual phosphates move within membrane
another way membranes can change
cholesterol content
- disrupts action between phospholipids
- fills gap between phospholipids to make it less permeable
one more way membranes can change
fatty acid structure
- saturated fatty acids fit tightly together
- unsaturated fatty acids don’t fit well because the kinks make spaces
what happens to membranes when it gets too hot
it becomes too liquid and you need to increase sat fatty acids and decrease cholesterol
what happens to membranes when it gets too cold
it becomes too solid and you need to increase unsat fatty acids and increase cholesterol
simple diffusionn
small NP- easy
large NP- limited
small p- limited
large p- very limited
facilitated diffusion
membrane proteins allow diffusion of small polar molecules
-passive process
channel proteins
hydrophillic tunnel
carrier protiens
revolving door
sodium-potassium punp
3 NA out
2 K in
both against concentratin gradient
bulk transport
moving stuff too big for carrier proteins
pinocytosis (bulk transport)
cell takes in fluid and dissolved solutes
phagocytosis (bulk transport)
cell takes in large particulate matter
receptor mediated endocytosis
specific molecules are taken in after binding to a receptor protein
exocytosis
cytoskeleton moves material out of the cell
ligand
signaling molecule released by a cell
