Membrane Transport Flashcards
What are the types of gradients?
- Pressure gradients
- Electrical gradients
- Concentration gradients
Define Fick’s Law of Diffusion
Gradient = (Concentration difference)(x-area)(temp)
/ (distance)(MW)
A scientific law is
an identifiable repetitive behavior in nature which always occurs
A scientific theory is
an explanation of how or why something (like a law) always occurs
According to Fick’s law, diffusion rate has a direct relationship with
- concentration difference
- area
- temp
According to Fick’s law, rate of diffusion has an indirect relationship with
- distance
- molecular weight
Diffusion is
- a type of passive transport
- caused by random movemment of particles of fluid, gas or particles
Net diffusion is
- Passive transport
- measurable random movement of particles of fluid, gas or particles
Osmosis is
the diffusion of a solvent through a membrane from an area of low solute concentration to an area of high solute concentration
When no channel is involved, transport of a solute across a membrane is fastest when
the molecule is small, lipid soluble and carries no charge
When a channel is involved, diffusion through a membrane is fastest when
- the molecule is small, carries a positive charge
or
- the molecule is small and is non-polar
Diffusion is _____ related to lipid solubility
- directly
- Increased lipid solubility = increased permeability
Diffusion is ______ related to molecular size
- inversely
- Increased molecular size = decreased permeability
Diffusion is ______ related to electrical charge
- directly
- postive charge = increased permeability (rate)
Dialysis is the
net movement of a solute through a membrane
Hemodialysis is the
removal of excess urea and K+ by dialysis of the blood
The characteristics of carriers are
- They are membrane-bound proteins (integral)
- They are highly specific to the solute(s) that they carry
- Maximum transport rates is reached when all attachment sites are full
- faster than channel transport but has a max threshold
- Transport can be blocked by inhibitors
The characteristics of Fascilitated diffusion are
- Requires a carrier
- Does not require ATP
- Faster than non-carrier diffusion
- Maximum transport rate when all binding sites are full
The action of a symport is
to move 2 molecules in the same direction (by one carrier)
The action of an antiport is
to move 2 different molecules in opposite directions (by one carrier)
Processes of endocytosis include
phagocytosis (eating) and pinocytosis (drinking)
Processes of exocytosis are
secretion (hormones, sweat, enzymes, etc.)
and excretion (waste)
Remember Na+ ___, K+ ___.
Na+ in, K+ out
Na+ in, K+ out
Na+ in, K+ out
Na+ in, K+ out
Na+ in, K+ out
Na+ in, K+ out
Na+ in, K+ out
