PhotosynthesisChapter 4
http://www.youtube.com/watch?v=pE82qtKSSH4
KEY CONCEPTThe overall process of photosynthesis produces sugars that store chemical energy.
Photosynthetic organisms are producers.
• Producers make their own source of chemical energy.
• Plants use photosynthesis and are producers.
• Photosynthesis captures energy from sunlight to make sugars.
Bill Nye: The Science Guy on Plants
• http://www.youtube.com/watch?v=zVD6n5mOw2E (2min)• http://www.youtube.com/watch?v=pdgkuT12e14
• Chlorophyll is a molecule that absorbs light energy.
chloroplast
leaf cell
leaf
• In plants, chlorophyll is found in organelles called chloroplasts.
How chloroplasts work
• http://education-portal.com/academy/lesson/chloroplast-structure-chlorophyll-stroma-thylakoid-and-grana.html#lesson
• The light-dependent reactions capture energy from sunlight.
– take place in thylakoids– water and sunlight are needed– chlorophyll absorbs energy– energy is transferred along thylakoid membrane then to
light-independent reactions– oxygen is released
• The light-independent reactions make sugars.– take place in stroma– needs carbon dioxide from atmosphere– use energy to build a sugar in a cycle of chemical
reactions
• The equation for the overall process is:
6CO2 + 6H2O C6H12O6 + 6O2
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplastchloroplast1
2
43
energy
stroma (fluid outside the thylakoids)
Bozeman Science
• http://www.youtube.com/watch?v=g78utcLQrJ4
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