ch14 flower leaf and stuff nutrients transport Flashcards
limiting factors in photosynthesis
Photosynthesis is enzyme-catalysed
carbon dioxide conc., temperature, light intensity
water not limiting factor?
- we made of 90% water, alw. in excess
pH seldom limiting factor?
- lol when will a plant change pH environment? it cant move after all.
photosynthesis word, chem eqn
carbon dioxide + water -(light, chlorophyll)-> glucose + oxygen
chem
6CO2 + 6H2O (light,chlorophyll) → C6H12O6 + 6O2
light dependant stage characteristics
- chlorophyll absorb light energy
- light energy used, photolysis, water, form o2 gas, hydrogen ions, ATP
- hence, light energy -> chemical potential energy (ATP)
ATP is a form of chemical potential energy
light independant stage
characteristics
chemical potential energy (ATP), reduction of co2 with hydrogen ions -> glucose
fates of glucose
- used directly, respiration
- convert -> cellulose
- convert -> sucrose
- convert -> starch
- convert -> fats
- convert -> amino acid
fate of glucose
d___ -> r____
direct -> respiration
release energy, biochemical reaction
fate of glucose
c__ -> c___
convert -> cellulose
synthesise cell wall, mechanical protection, cell
fate of glucose
c___ -> s___
c___ -> s___
convert -> sucrose
for transport, phloem, leaves -> all parts, plant
convert -> starch
storage
fate of glucose
c__ -> f___
convert -> fats
storage
synthesise protoplasm (i.e. cell surface membrane)
fate of glucose
c__ -> a__ a__
convert -> amino acids
synthesise protoplasm (i.e. cell surface membrane)
leaf struct (from top to bottom)
- cuticle
- upper epidermis
- mesophyll layer
- palisade mesophyll layer
- spongy mesophyll layer
- guard cells
- stoma (singular)
cuticle struct
waxy, waterproof layer
cuticle funct
prevent excessive water loss, evaporation
upper/lower epidermis struct
single layer, transparent cells, no chloroplasts
thicker cell walls
upper/lower epidermis
allow light pass through -> mesophyll layer
mechanical protection, leaf
mesophyll layer struct
palisade + spongy mesophyll cells
thin lining moisture, surrounding cell wall
mesophyll layer funct
allow gas, co2, dissolve before diffusing, cells
palisade mesophyll struct
elongated, cylindrical cells
closely pakced
palisade mesophyll cells funct
max absorption light energy
photosynthesis
spongy mesophyll layer struct
irregularly shaped cells
loosely packed
VASCULAR BUNDLE
2. xylem
3. phloem
spongy mesophyll layer
funct
- create intracellular air spaces
faster diffusion, gases like co2
within leaf - phloem transports sucrose, amino acids leaves -> all parts plant
- xylem transports water, mineral salts roots -> leaves, photosynthesis
photosynthetates -> raw materials for photosynthesis
magnesium ions for
essential, synthesis of chlorophyll
guard cells struct
contain chloroplasts
cell wall, uneven thickness
can change shape
by altering turgidity, cell
guard cells funct
controls opening, closing stomata (PLURAL)
stoma (SINGULAR) struct
small pore
surrounded, pair, guard cells
stoma (SINGULAR) funct
gases like co2
diffuse in, out, leaf
transpiration
- loss, water vapour
aerial parts, plant
especially from stomata of leaves - inevitable consequence, gaseous exchange, plants
translocation
- via phloem, transport, sucrose, amino acids, leaves -> other parts, plant
appearance, xylem vessels
large, hollow cells
thicker walls
visible lumen
appearance, Phloem sieve tube element
smaller compact cells
2 struct of xylem
- no protoplasm, cross walls, hence hollow
- cell wall strengthen w/ lignin (strong, rigid)
xylem adaptation
n__ p__, c__ w__
h__ h__
no protoplasm, cross walls, hence hollow
- reduce resistance, flow of materials
- faster transport, water, dissolved mineral salts
- roots -> other parts, plant
xylem adaptation
c__ w__ s__ w/ l__ (s__, r__)
cell wall strengthen w/ lignin (strong, rigid)
1. mechanical support, plant
2. prevent xylem vessel collapse, negative pressure generated -> transpiration pull
phloem sieve tube element struct
- sieve tube elements, reduced cytoplasm, perforated cross walls
- companion cell, numerous mitochondria
is osmosis for water vapor?
no
liquid water only
phloem
s__ t__ e__, r__ c__, p___ c__ w__
sieve tube elements, reduced cytoplasm, perforated cross walls
1. reduce resistance, flow of materials
2. faster translocation, photosynthetates -> sieve tube element, active transport
phloem
companion cell, numerous mitochondria
1. release energy
2. loading of photosynthetates, sieve tube element
3. by active transport
root pressure
- endodermis, root -(pump)-> xylem vessels, mineral salts by active transport
- generating region of lower water potential in xylem
- water moves from soil down water potential gradient through cells, cortex -> xylem by osmosis
- generate region, high hydrostatic pressure -> xylem (root pressure)
- root pressure push water, dissolved mineral salts up xylem
capillarity
- intermolecular force, attraction exist btwn molecules
- forces of adhesion btwn water molecules, cellulose cell walls, move water slightly up xylem vessel
- forces of cohesion pull water, continuous column up xylem vessel
transpiration pull
Where cont. flow of water, generate suction force (transpiration pull), draw water, dissolved mineral salts up xylem vessels, roots -> leaves
- water move, xylem vessel -> surrounding mesophyll cells down water potential gradient by osmosis
- water moves out of mesophyll cells by osmosis, replace water lost from surface of mesophyll cell
- in intraceullular air spaces, water from SoMC evaporate -> water vapor
- water vapor move, intercellular air spaces -> external env by diffusion thru stoma
- transpiration: loss of water vapor, stomata of leaves
when does wilting occur
- rate of water loss, plant by transpiration > rate of water intake, plant through roots
- result, excessive water loss, cells -> flaccid
2 effects of transpiration on plant cells
- guard cells, flaccid -> stomata close
- mesophyll cells, flaccid -> leaves curl up
WILTING
advantages of s__ c__
stomata close
prevent further water loss, transpiration
guard cells, flaccid
WILTING
disadvantages of s__ c__
stomata close
reduced intake, co2, reduced rate, photosynthesis
guard cells, flaccid
WILTING
advantages of l__ c__ u__
leaves curl up
1. trap layer of moisture near stomata
2. reduce further water loss by transpiration
3. reduce exposed surface area => solar radiation, leaves cool down
mesophyll cells, flaccid
WILTING
disadvantages of l__ c__ u__
- decreases rate of transpiration
- decreases amt of water transported up the xylem
- decreases exposed surface area -> light
- decreases rate of photosynthesis
4 variables that varies rate of transpiration
- air movement
- temperature
- humidity
- light intensity
increase rate of transpiration
a___ m__
air movement
1. increased air movement, increased rate, transpiration
2. wind carry water vapor away, surface of leaves
3. steeper conc. gradient water vapour, inside, outside, leaves
4. increase rate, diffusion, water vapor molecules -> outside leaf, via stomata
decrease rate of transpiration
h___
humidity
1. increased humidity, decrease rate, transpiration
2. increase conc., water vapor, outside leaves
3. less steep, conc. gradient, water vapor btwn inside, outside leaves
4. decrease rate, diffusion of water vapor molecules -> stomata
increase rate of transpiration
t____
temp
1. increased temp, increase rate, transpiration
2. increase rate, evaporation, water from surface, mesophyll cells
3. increase rate, diffusion, water vapor -> stomata
increase rate of transpiration
l___ i___
light intensity
1. increase light intensity, increase rate, transpiration
2. more stomata, open
3. increase rate, diffusion, water vapor molecules -> outside, leaves via stomata
