photosynthesis: why, where and how…
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Photosynthesis: Why, where and how…. An overview of photosynthesis. Which organisms can photosynthesise ?. Which organisms can photosynthesise ?. Green plants, phytoplankton and cyanobacteria Phytoplankton and cyanobacteria supply half of all atmospheric oxygen - PowerPoint PPT PresentationTRANSCRIPT
Photosynthesis: Why, where and how…
An overview of photosynthesis
Which organisms can photosynthesise?
Which organisms can photosynthesise?
• Green plants, phytoplankton and cyanobacteria
• Phytoplankton and cyanobacteria supply half of all atmospheric oxygen
• ‘Red tides’ are caused by photosynthetic protists
Where does photosynthesis occur in plants?
Photosynthetic pigmentsan introduction…
Photosynthetic pigments
• A pigment is a substance that absorbs light• Plants have pigments in the thylakoids of their
chloroplasts: chlorophylls, carotenoids and• Chlorophyll a is directly involved in
photosynthesis while chlorophyll b is an accessory pigment, since it assists in capturing light energy
• Caratenoids give leaves their red, orange and brown hues during autumn
• Why are leaves green?
Carotenoids and chlorophyll: welcome to autumn…
The ‘where’ of photosynthesis: The Chloroplast
Carbon dioxide is often a limiting factor on the rate of photosynthesis
Measuring the rate of photosynthesis
• P. 77 in textbook• Oxygen production:
‘direct measurement’• Carbon dioxide
measurement: ‘Direct measurement’
• Biomass measurement: ‘indirect measurement’
Your next IA
• ‘Design an experiment which evaluates the effect of ONE limiting factor (temperature, light intensity,
light colour or carbon dioxide concentration’ on the rate of photosynthesis’
• You may want to compare different types of plants in your experiment…
The reactions of photosynthesis