Transport Through Membranes Flashcards
What is another word for diffusion?
Simple diffusion
What is simple diffusion?
The net passive movement that results from the random kinetic movement of individual molecules from a region of high to low concentration
Spontaneous, no energy requirement, inherent tendency
What is the rate of diffusion a complex function of?
The concentration gradient and the “resistance to flow”
What is the concentration gradient equation?
I can’t type this shit out tf
What does the concentration gradient look like on a graph?
Starts high and starts decreasing linearly
What is the “resistance to flow”?
The physical and chemical properties of the medium through which the substance is diffusing (density, viscosity, polarity…)
The molecular weight of diffusing substance accord to Graham’s Law (heavier = slower)
What is facilitated diffusion?
What is osmosis?
The diffusion of a solvent through a semipermeable membrane
High to low concentration of solvent (water rlly)
What is a solution comprised of?
Solute: molecule being dissolved
Solvent: the substance the solute is being dissolved in
What is a semipermeable membrane?
A membrane that is permeable to the solvent but NOT permeable to the solute
EX: Water can pass through, but sugar cannot
What characteristics does an osmotic solute contain?
Soluble in the solvent
Cannot pass through the semipermeable membrane
What is a hypotonic osmotic system?
Water flows INTO the cell and SWELLS UP
What is a hypertonic osmotic system?
Water flows OUT of the cell and undergoes lysis
What is an isotonic osmotic system?
There is no net movement of water in or out of the cell
No effect
What environment do plant cells prefer to live in?
Plants prefer to live in HYPOTONIC environments
No lysing occurs due to turgor pressure
