MT1 showdown Flashcards
What prevents the column of water inside of the xylem from breaking?
Hydrogen bonds. This column is called the soil-plant atmosphere continuum
What happens to transpiration when you raise air temp without raising leaf temp? What if you do allow leaf temp to increase?
Without change: the increase in temperture raises the water vapor concentration of the environment, slowing transpiration
with change: the increase in temperture will increase the vapor saturation pressure inside the leaf and increase transpiration
What does Q stand for in the statment Q + V + C =0
IR radiation
What does V stand for in the statment Q + V + C =0
evaporative cooling/transpiration
*Turns possitive during condensation
What does C stand for in the statment Q + V + C =0
Convection
What happens to V, C and Q if the temperture drops on a leaf?
Q: starts to turn negative as the plant looses IR radation
V and C: raise to compensate
What is incipient plasmolysis? What is pressure potential at that time and when does it occur?
Incipient plasmolysis happens when the cells are a pressure potential of 0. This occurs when plasmolysis is first observed .
When does the pressure inside of a pressure bomb equal that of the leaf structure?
Right when the sap apears
Pressure potential of the orignal xylem = - pressure potential of the pressure bomb
what is the water potential of xylem on a plant? What is the water potential of a leaf cell on a plant?
Water potential of xylem = the pressure potential
Water potential of leaf cell= 0 (at equilibrium with surroundings)
WHat is rate of water loss directly dependent on?
The difference in concentration over distance (delta c/delta x)
WHat is the rate of transpiration directly dependent on?
the difference between the leaf cell and the xylem
Is it when observed co/ci greater or less than expected co/ci when active uptake is occuring?
It is when oberseved co/ci is less than
What is the formula for transpiration rate?
J=(kRT(delta C leaf-air)/r
What is the difference between the chemical potential of a solute and the chemical potential of water
chemical potential of a solute includes the term for charge (zFE). Chemical potential of water includes gravitational potential (mgh)
When is delta c higher: a hot or cold day?
Cold day. Less water vapor in the air
