Chapter 7 Photosynthesis_student version
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Transcript Chapter 7 Photosynthesis_student version
CHAPTER 7
PHOTOSYNTHESIS: USING LIGHT
TO MAKE FOOD
General Biology
CM Lamberty
BIOLOGY AND SOCIETY
Green Energy
Wood…fossil fuels….biomass/biofuels
Renewable, less S, wildlife habitats, reduce
erosion, disversification
4% of all E in US
THE BASICS OF PHOTOSYNTHESIS
Process by which plants, algae and certain
bacteria transform light E into chemical E
Uses CO2 and H2O as starting materials
Chemical E then stored in bonds of sugar
Plants = autotrophs
CHLOROPLASTS: SITES OF PHOTOSYNTHESIS
Chloroplasts:
Found
Chlorophyll
Stomata:
Stroma:
Thylakoids:
Grana:
THE OVERALL EQUATION FOR PHOTOSYNTHESIS
6 CO2 + 6 H2O
C6H12O6 + 6 O2
CO2 and H2O were waste products of cell. resp
A PHOTOSYNTHESIS ROAD MAP
2 stages of photosynthesis
Light Reactions
Calvin Cycle
THE LIGHT REACTIONS: SOLAR…CHEMICAL
THE NATURE OF SUNLIGHT
Radiation
Electromagnetic energy
Waves
Wavelength
EM spectrum
Light hits object and is either absorbed or reflect
CHLOROPLAST PIGMENTS
Chlorophyll a
Chlorophyll b
Carotenoids
HOW PHOTOSYSTEMS HARVEST LIGHT E
Photon:
Shorter wavelength
Pigment MQ absorb photon
Thylakoid membrane
HOW LIGHT RXNS GENERATE ATP & NADPH
2 types of photosystems cooperate
Water-splitting photosystem
Transfer between systems
NADPH-producing photosystem
HOW LIGHT RXNS GENERATE ATP & NADPH
Light reactions taking place in thylakoid
membrane
2 photosystems and electron transport chain
ATP production is similar to cellular respiration
Difference:
THE CALVIN CYCLE: MAKING SUGAR FROM
CO2
Sugar factory within stroma of chloroplast
Cycle: starting material regenerated each turn
SOLAR DRIVEN EVOLUTION
Hot, dry climates plants continue photosynthesis
while conserving water
C4
CAM