Water Transport and Plant Signaling Flashcards
Describe proton pumps in plants
Transport proteins that pump H+ out
What to proton pumps create?
create membrane potential
Describe membrane potential
negative charge on the inside positive on the outside
How does membrane potential affect protons?
Protons end up flowing back into the membrane, using their movement to do work
Describe cotransport
The proton gradient is used to actively transport other solutes in.
Solute potential is also called what?
osmotic potential
Solute potential is proportional to the number of ________ ________ _______.
dissolved solute molecules
Is solute potential always positive or negative?
negative
Solute potential determines what?
where osmosis takes water
Define pressure potential
the physical pressure on a solution
Is pressure potential negative or positive?
either
What does pressure potential determine?
where water is pushed or pulled
Define water potential
the combined effects of solute potential and pressure potential
What does water potential determine
where water will flow
If a plant cell has lost water, it is called ______.
flaccid
Describe plasmolysis
protoplasm (cytoplasm+nucleoplasm) shrinks and pulls away from the cell wall
Plasmolysis has what effect on water potential?
lower water potential outside the cell
When the protoplasm swells and stays stiff agains the cell wall, it is called _____.
turgid
Turgid has what effect on water potential?
lower water potential in the cell
What are the paths to bring water in?
apoplast, symplast, plasmodesmata
Describe the apoplast path
formed by connecting cell walls
Describe the symplast path
connecting cytosol of cells
Describe plasmodesmata
gaps that connect neighboring cells
What is used to move water in the plant?
root pressure
Describe root pressure
water flowing into the xylem from the root cortex due to ions in the xylem
What is used to move water up the plant?
transpiration
Describe transpiration
the loss of water through stomata causing water to be
pulled up xylem
Water that is pulled up xylem during transpiration is called what?
xylem sap
What quality of water allows transpiration?
adhesion and cohesion
What part of the plant regulates transpiration?
stomata
What do guard cells do? What is the required condition for this action?
Bow out and open stomata. Happens when turgid
What are some factors that cause stomata to open or close?
- guard cells
- daylight
- decreased CO2
- Drought
- Heat, wind, and dry conditions
Day light or decreased CO2 cause stomata to ____.
open
Drought or flaccid cells cause stomata to ____.
close
Heat, wind, and dry condition cause ______ _____ ____..
excess water loss
What is used to move water down the plant?
translocation
Define translocation
moving sugars down the plants
What are source cells?
sugar producing cells that dump sugars into sieve tubes
The water drawn in sieve tubes is called what?
phloem sap
Describe sink cells
growing cells that consume sugars. takes sugars from the sieve tubes
What is used for plant signaling?
hormones and environmental cues
What is Auxin (IAA)?
a hormone that primarily causes young cell elongation (loosens the cell wall) and lateral root formation, stops leaves from falling, regulates fruiting, and causes vascular differentiation
Describe cytokinins
small proteins that aid in stimulating cell division
____ must be present with ________ to cause cell division
Auxins; cytokinins
The ratio of Cytokinin to Auxin does what?
determines what undifferentiated cells become, and control apical dominance
Describe gibberelins
any group of plant hormones that promote stem elongation, fruit production, and germination
Brassinosteroids function similar to _____.
auxin
What are the functions of brassinosteroids
prevent leafs from dropping and causes xylem to differentiate
Describe Abscisic Acid (ABA)
a hormone that inhibits plant growth. Keeps seeds dormant, closes stomata during drought
What does ethylene do?
causes fruit to ripen, helps seedlings grow around obstacles, apoptosis, and causes leaves to fall off
What is apoptosis called in plants?
senescence
What is it called when leaves fall off of plants?
abscission
What are florigen
hypothetical flowering hormones
Short day and Long day flowers grow on the same plant when ______.
grafted
What is phototropism
plant response to light
What do blue light receptors do?
control things such as stem elongation and stomata opening
Red light receptors also called what?
phytochromes
What do phytochromes do?
control things such as seed germination and shade avoidance
A plants response to a period of light (like flowering) is called?
photoperiodism
Short Day plants flower when?
in fall
Give an example of a Short Day plant
soybean
Long Day plants flower when?
in spring
Give an example of Long Day plants
spinach
When a plant doesn’t rely on a photo period, it is called what?
Day neutral
Give an example of a day neutral plant
rice
Plant response to gravity is called?
gravitropism
Roots respond _______ to gravity.
positively
Stems respond _______ to gravity.
negatively
Plant response to touch is called? Give an example
thigmotropism. (Do it for the) Vine
