Water potential Exam questions

Описание: Plants use water potential to transport water to the leaves so that photosynthesis can take place.
Water potential is a measure of the potential energy in water as well as the difference between the potential in a given water sample and pure water.
Water potential is represented by the equation Ψsystem = Ψtotal = Ψs + Ψp + Ψg + Ψm.
Water always moves from the system with a higher water potential to the system with a
lower water potential.
Solute potential (Ψs) decreases with increasing solute concentration; a decrease in Ψs causes a decrease in the total water potential.
The internal water potential of a plant cell is more negative than pure water; this causes water to move from the soil into plant roots via osmosis..

solute potential: (osmotic potential) pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane
transpiration: the loss of water by evaporation in terrestrial plants, especially through the stomata; accompanied by a corresponding uptake from the roots
water potential: the potential energy of water per unit volume; designated by ψ Water Potential

Plants are phenomenal hydraulic engineers. Using only the basic laws of physics and the simple manipulation of potential energy, plants can move water to the top of a 116-meter-tall tree. Plants can also use hydraulics to generate enough force to split rocks and buckle sidewalks. Water potential is critical for moving water to leaves so that photosynthesis can take place.

Questions:

Although water normally diffuses into a root from the soil based on water potential differences, it is possible, under the right soil conditions, for water to diffuse out of the root cells in the cortex and back into the soil.


If a cell has a water potential of -0.3 MPa, water will diffuse from that cell toward a cell whose water potential is

What condition will be found in a plant cell that is taking up water from an external solution?


What will result with water potential from an increase in the solute concentration?