5.5 Osmosis Flashcards
What is osmosis?
Movement of water
across partially permeable membrane
from high to low water potential.
Passive process.
What is water potential?
measure of the quantity of water compared to solute
measured by pressure exerted by water molecules in kPa
What is the symbol for water potential & what are the units?
Ψ
measured in kPa
What does a high water potential mean in terms of the quantity of water compared to solute?
Solution contains high quantity of water but low quantity of solute
solution is dilute
What does a low water potential mean in terms of the quantity of water to solute?
Solution contains low quantity of water & high quantity of solute
solution is concentrated
What is the water potential of pure water?
0 kPa
(the higher the quantity of water, the higher the water potential. Pure water consists of only water without solute, ∴ very high water potential)
The more concentrated the solution, the ____ the water potential.
lower
The less concentrated a solution, the ____ the water potential.
higher
What is hydrostatic pressure?
Pressure created by water
in an enclosed system
What are the units of hydrostatic pressure?
kPa
What is a hypertonic solution?
Solution which is more concentrated
than the other
What is a hypotonic solution?
Solution which is less concentrated
than the other
What is an isotonic solution?
Solution which is equally concentrated/dilute
as the other
What happens to an animal cell when it is submerged in a:
a. Solution which is isotonic to the cell
b. Solution which is hypotonic to the cell
c. Solution which is hypertonic to the cell
a. No change to cell, ∵ water potential is equal in both solutions, so no net movement of water.
b. Cytolysis (cell bursts), ∵ water potential is lower in cell than in surrounding solution, so water moves into cell.
c. Crenation, ∵ water potential is lower in surrounding solution, so water moves out of cell.
What is cytolysis?
Bursting of an animal cell
caused by increased hydrostatic pressure
due to water moving in by osmosis
