Theme 4 Homeostasis In Land Plants Part 3 Flashcards
(38 cards)
In which ways do plants move water and solutes
Into and out of cells
Laterally from cell to cell
Over long distances from the root to shoot or vise versa
They move substances across cell membranes by both active and passive transport
What is the short distance transport in plants
Moving solutes
into and between cells from root hairs
To and from vascular tissues (xylem and phloem)
What is the long distance transport in plants
Moving solutes between the root and the shoot part of the plant
Up and down the whole plant
What does the xylem transport
The pholem
H2O and o2
Sugars
What is osmosis
How the water moves
Passive movement of water across a selectively permeable membrane
What are aquaporin proteins
Proteins that let water move rapidly through hydrophobic membrane core
For large amounts of water transport
What minerals can easily diffuse easily into a cell
H2O co2 o2
What is water potential
The potential energy of water
The driving force that determines which way the water moves
What is the potential energy of pure water
0 mega pascals, no solutes, standard atmospheric pressure
What makes up water potential
Solute potential + pressure potential
Which way does water move
From high water potential to low water potential
What lowers water potential
The presence of solutes
In solute added to pure water (0 megapascals). The water potential turns negative
Adding solution will never make postive impact, solute potential always negative
What is pressure potential
When does it increase water potential
The force required to stop water movement
Can be postive pressure or negative pressure
If you apply postive pressure the water potential goes up
If you apply negative pressure the water potential goes down
If you add solute to water on one side…
The water potential on that side goes down
Water moves to that side by osmosis (move to lower potential)
If you add same amount of pressure potential and solute potential…
Pushing down into water makes positive potential
Solutes make negative potential
Cancels
Net zero change in water potential, no net movement on both sides it’s zero
If adding more pressure potential than solute potential to one side…
Net Increase in water potential of the solution on that side
So water moves to the left (to lower potential
If apply more negative pressure (pulling water up instead of pushing) to one side and have less solute on the other side ….
Side with negative pressure has less water potential than side with solute
So water moves to side of negative pressure
(Left)
Moves until equilibrium is reached on both sides
Which situation applies to the plants
The negative pressure one one side and solutes on other
Transpiration out of stomatal pores acts as a vaccume
The lignin in xylem makes it so the vaccume doesn’t collapse the xylem.
Then solutes and water are pushed up
Pic not in notes
Ok
Plants always try to maintain …
High solute concentration inside of the cell
Means in the plants cell the water potential is negative. (Cause of solutes potential)
Always drawing more water in
How do plants counter the negative cell water potential to reach equilibrium
The massive central vacuole takes water into itself and maintains turgor pressure
What is the tonoplast membrane what does it do
The membrane of the central vacuole
Helps maintain turgor oressure
What is plasmolysis
The wilting in plants that happens because the soil is dry (water potential in soil is low)
Water travels to soil from plants
Plant losing water wilts
Water will always follow….
What does the plant do
The solutes
If taking more solutes, more water following
The pressure potential goes up (more postive turgor pressure)
The plant adjusts the solutes to keep itself turgid and let water come in until equilibrium is reached
