Plants And Water Flashcards
What is the water potential a measure of ?
The water potential is the ability of water to move from one place to another I.e do work
What does the value of the water potential mean ?
If the water potential is more positive then it is more free to move.
What is the solute potential ?
S is the solute potential, the movement of water due to the presence of solutes e.g moves from less concentrated solutions to more concentrated solution.
What is the pressure potential ?
This is the potential ability for water to move due to a difference in hydrostatic pressure. A positive pressure potential allows the plant cells to become turgid.
What is the matric potential ?
This is the ability for surfaces to hold water due to the presence or lack of charge e.g dry sand environments have a very high matric potential as the sand is charged and holds onto a vineer of water very tightly
What happens to plant cells in concentrated solutions ?
The solute potential will be very negative inside the cell and cause water to move out of the cell. This leads to the pressure potential to drop also. The cell becomes plasmolysed.
What happens to a plant cell in dilute solutions ?
Plant cells will become turgid as the solute potential will become high, causing the water potential to increase. Therefore water will move into the cell and increase the pressure potential.
What are the problems produced by water potentials in mangroves ?
Roots of mangroves are anchored in salt water. The potential of these waters can increase to only -1.5 MPa and the potential of the cells in mangrove plants can only decrease to -2MPa. Therefore there is only a small potential difference of 0.5MPa. This small difference means that they can only drive a growth of up to 20m in height.
