3.2 Photosynthesis Flashcards
Leaf
Thin
Short diffusion pathway for light
More light reaches chloroplasts
Stroma
Guard cells to open/close
Allows carbon dioxide to diffuse into leaf
Air spaces in spongy mesophyll
Allows CO2 to diffuse into palisade cells
Large surface area
Allows maximum light absorbency
Palisade cells have a large vacuole
Stores water
Palisade cells are cylindrical at right angles to leaf surface
Ensures chloroplasts are at top of cell
Vacuole at bottom
Waxy cuticle
Light penetrates through to palisade mesophyll
Many chloroplasts in palisade cells
More photosynthesis
Chloroplasts move within palisade cells
Position themselves for max absorption of light at different times of day
CO2 + H2O =
O2 + C6H12O6
Types of pigment
Chlorophyll a
Chlorophyll b
Carotene
Xanthophyll
Chlorophyll a
Green
Chlorophyll b
Green
Carotene
Orange
Xanthrophyll
Yellow
Pigments that contain magnesium
Chlorophyll a
Chlorophyll b
Photosystem
Light harvesting from cluster of pigment molecules organised ina very precise way
What is in a photosystem
Primary reaction centre of chlorophyll A
Organised around this in a y shaped funnel is a series of accessory pigments consisting of chlorophyll B and carotenoids
Carotenoids
Carotene
Xanthophyll
Chlorophylls absorb
Red and blue/violet
Carotenoids absorb
Blue/violet
Why is phosphate needed in plants
Makes ATP and DNA
Why are nitrates needed for plants
Making amino acids and DNA
Why is magnesium needed in plants
Makes chlorophyll
Englemanss experiment
Refracted light with a prism
Explain englemanns experiment
-Aerobic Bactria cluster at the red and blue wavelengths and fewer at green wavelength
-More O2 concentration at red and blue
-More photosynthesis at these and photosynthesis produces O2
-Because these pigments absorb light best at those wavelengths
Control englemanns experiment
Remove prism so white light is used
Aerobic bacteria is distributed evenly along the photosynthetic algae
2 parts of photosynthesis
Light dependant
Light independent/Calvin
Light dependent
Happens on the thylakoid membrane + produces ATP and NADPH2
Used for light independent reaction
Light independent
Occurs in stroma
Produces glucose
