Transcript AP Bio Water Potential

AP Bio Water Potential
• Water potential measures the tendency of
water to leave one place in favor of another
• Water will always move from an area of high
water potential to low water potential
• Water potential= pressure potential + solute
potential
What effects water potential
• Addition of a solute (lowers water potential)
• Physical pressure (raises water potential)
What is solute potential
• The effect that solutes have on a solution’s
overall water potential.
• Always a negative value
Calculating percent change
final-initial= divided by initial= x100=%
Graphing percent change
• To determine the molar concentration of
potato core, see where the line crosses the
ZERO (x axis)
• This is where there is a molar concentration of
sucrose with a water potential that is equal to
the potato tissue water potential
Solute potential formula
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Solute potential= NEGATIVE iCRT
i=ionization constant (1.0 for sucrose)
C= Molar concentration (given)
R= pressure constant (0.0831)
T= temperature in Kelvin (273 + C)
water potential is equal to solute potential