Topic 4 (all) Flashcards
The name of the surface of gas exchange for plant
Spongy mesophyll cells
How is the leaf adapted for gas exchange (3)
1)Big surface area
2)Short diffusion distance between stomata and spongy mesophyll cells
3)Ventilation around leaves to maintain concentration gradient
What makes up a stomata
Two guard cells
How does a stomata open (4)
1)Potassium ions enter via active transport
2)which lowers solute potential
3)Water move down concentration gradient into the cell
4)Cells become turgid and bend
Where are lenticles found
On impermeable surfaces on truck
What are lenticles and how are they adapted to gas exchange (2)
1)Loosly packed cells
2)Contains air space
The function of xylem (2)
1)Transport water
2)Transport mineral ions
The function of phloem (2)
1)Transport sucrose
2)Transport amino acid
How does the structure of xylem adapts to its function (3)
1)Cell walls lignified with rings and spirals
-prevents vessels from collapsing under tension
-increase flexibility
2)Made up of dead cells with no organelles
-Wide lumen for unrestricted water flow
3)End walls break down
-continuous tube for water transport
How does the structure of phloem adapts to its function (3)
1)Sieve tube cells with limited organelles
-Create space for sugar transport
2)Each sieve tube cells are connected via sieve plates with pores
-Form direct connections from one sieve tube cell
to the next
3)Compaion cells are connected to sieve tube cells via plasmodesmata
-Companion cells with dense organelle including
mitochondria used in respiration to produce ATP
for sugar transport
What is apoplast pathway
Transport of water via fully permeable cell wall
What is symplast pathway
Transport of water via plasmodesmata
What stops apoplast pathway from transporting water
Casparian strip in the cell wall which is impermeable to water
What is transporation
The loss of water through stomata via diffusion
Factors affecting rate of transpiration (4)
1)Temperature
2)Air movement
3)Humidity
4)Light intensity
How does temperature affect the rate of transpiration
Water molecules gain kinetic energy
How does air movement affect the rate of transpiration (2)
1)Moves water molecules around leaf
2)Maintains deep concentration gradient
How does humidity affect the rate of transpiration
High humidity means small concentration gradient
How does light intensity affect the rate of transpiration (3)
1)Plants needs CO2 to photosynthesize
2)Stomata opens to absorb CO2 under the presence of light
3)High light intensity means more stomata open
What is translocation
The movement of water between the xylem and the phloem that moves sugar from source to sink
What are the two stages of photosynthesis (2)
1)Light dependent stage
2)Light independent stage
Where does the light dependent stage of photosynthesis
The grana (Stack of thylakoid membrane)
Where does the light independent stage take place
The stroma
What are the two types of reactions in light dependent stage (2)
1)Cyclic
2)Non-cyclic
