Diffusion and Transport Flashcards
(32 cards)
what is Brownan motion?
random motion
- causes collisions that bounce off each other
what is diffusion?
movement of high concentration to a low concentration
- diffusion tends to collapse concentration gradients
what is the equation for ability to diffuse?
in the ability to diffuse equation what happens if you increase the temperature
it increases the diffusion
in the ability to diffuse equation what happens if you raise the viscosity?
you decrease diffusion
in the ability to diffuse equation what happens if you increase the surface area or the radius of molecule?
you decrease the dissusion
what is the equation for the mean displacement for multiple dimensions?
x=square root 2Dt
in the mean displacement for multiple dimensions what happens to the distance if doubled?
you quadruple the time
lipid membranes are _____?
selectively permeable
which means only certain molecules can get through
IF there is NO concentration differences across the membrane then there is ____ flux
NO NET FLUX
what is the equation for simple diffusion across a membrane?
J = P (C1+C2)
C1 = extracellular concentration
c2 = intracellular concentration
J = Flux
P = permeability coefficient
In simple diffusion is energy required? net flux occurs? what can go through?
- No energy required
- net flux occurs when concentration DIFFERENCE is present
can go through: - gas exchange - steroids - hydrophobic drug movement
cannot is FATS
What is osmosis?
the movement of water from a low concentration to a high concentration
- moves to dilute the solute
- osmosis tends to equalize the solute concentrations on the 2 sides
solute vs solvent
Solute is substance that is being dissolved (salts, proteins, sugars)
solvent - is the thing that is disolved in (water, liquid)
what is simple diffusion? what cells can pass through
No energy needed
passes through easily no help
molecules:
- gas exchange
- steroids
- not fats
- hydrophobic drug movements
-
what is osmosis?
the movement of water from a low solute concentration to high solute concentration
- osmosis tends to equalize the solute concentrations on the 2 sides
what is isotonic?
the equal distribution of solutes and solvents
what is hypertonic?
more solute outside of cell so water moves to it leaving the cell to shrink
what is hypotonic?
Fewer solutes in solvents than in cells
- causes cell to swell
what was the case study for hyponatremia?
- A marathon runner drank excess water causing solute concentration to be less
- cells swelled and died - Hold your Wee for a Wii
- drank too much water and wasn’t peeing out
- cells swelled and she died 6 hours well
what was the case study for hypernatremia?
(dehydration)
- loss of water not Na+
- low ADH (antiduredic hormone)
Does every cell have a Aquaporin?
( Water channel )
- only certain cells that need that water faster then using diffusion
what is facilitated diffusion? how does it work
High concentration to low concentration
- uses transmembrane proteins
1. ion channels
2. carrier proteins - binds to the ion to pull it in
what molecules can pass during facilitated diffusion?
Large and small molecules
No energy used (passive)
- glucose
- fructose
- amino acids
- ions
