B8 - Photosynthesis Flashcards
photosynthesis
-endothermic reaction
-energy to chloroplasts - light
-converts co2 + water to o2 and glucose
endothermic reaction
-input energy from environment
-uses more energy from environment than released
by product of photosynthesis
-o2
balanced equation
6Co2 + 6H2o —> C6 H12 O6 + 6O2
glucose
-used immediately by cells
-converted to insoluble stores
Leaf adaptations
-broad
-thin
-chloroplasts
-veins
-air spaces
-guard cells
Leaf adaptations: broad
-more SA
-max sunlight
Leaf adaptations: thin
-short diffusion distance for gases
Leaf adaptations: chlorophyll
-absorbs light
Leaf adaptations: veins
-xylem = more water to cells
-phloem = removes waste
Leaf adaptations: air spaces
-co2 + o2 enter leave cells
Leaf adaptations: guard cells
-open / close stomata
-regulates gas exchange
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Algae
-aquatic organism
-photosynthesises in water
Adaptation of Algae
-large SA to absorb co2 in water (dissolved)
-o2 released dissolved
limiting reactant
resources in short supply
-affect rate of photosynthesis
light
-more = increases rate
-brighter = faster rate
temp
-increase = more photosynthesis
-too high = denatured = rate falls
Co2
-most common limiting reactant
-increase = speeds up rate
Co2 concentration at night/ morning
-increases at night as plants respire
-as L.I + temp increases = co2 falls
Chlorophyll
-limited = decreases rate
ornamental plants and chlorophyll
-have some chlorophyll free areas
-limited growth compared to green plant
Mg deficiency
-no chlorophyll made
-plant may die
In dim light, leaves
turn green
Light intensity formula
L.I ∝ 1/d2
plants respiration
24hrs a day
-growth
glucose used in
-respiration
-storage
glucose makes
-cellulose
-starch
-complex carbs
cellulose
-strengthen cell wall
starch
-insoluble
-store
why can’t glucose be stored
-affect osmosis rates
-affect water balance
-
glucose forms amino acids by
-combining sugars + nitrate ions + mineral ions from soil
amino acids
-form enzymes
-by respiration energy
starch use
-energy store for when it’s dark
-survive winters (stored in bulbs - potatoes)
Carnivorous plants eg
-pitcher pants
-venus fly trap
-sundews
Carnivorous plants are adapted to
-grow in nitrate-poor soil
How do Carnivorous plants obtain nutrients
from their prey
Lipids formed by
-glucose from photosynthesis
-energy from respiration
Lipids use
-store energy
-strengthen cell wall
-eg seeds
Garden greenhouse
-polytunnels to grow crops
-more controlled
-warmer atmospere = increases rate
Hydroponics
-ensures perfect condition for growth
-controlled by computer software
-expensive
-high profits
Pros of hydroponics
-less staff needed
-shorter growth time
-larger/cleaner crops
Cons for hydroponics
-lots of electricity / gas used
-expensive monitoring equipment
