Photosynthesis
Photo + Synthesis
• Photosynthesis is made up of two Latin words.
• Photo is the first; it means “light”.
• Synthesis is the second; it means “to put together”.
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T1
Photosynthesis
Requirements for Photosynthesis
• In order for photosynthesis to occur, three things
must be present and available to the plant.
– Water
– Carbon Dioxide
– Solar radiation (sunlight)
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T2
Photosynthesis
What Does Photosynthesis Do?
• Transforms sunlight into chemical
energy (sugars).
• Fixes atmospheric carbon.
• Produces oxygen as a by-product.
• Frees water from the atmosphere.
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T3
Photosynthesis
The Equation for Photosynthesis
Light
Energy
6 CO2 + 12 H2O -------> 1 C6 H12 O6 + 6 H2O+ 6O2
This means that carbon dioxide, water, and the sun’s
energy are used by plants to make sugars, water, and
oxygen.
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T4
Photosynthesis
Light Reactions
• This reaction only occurs during daytime, or when
there is artificial light provided.
• Light energy is converted into chemical energy
used during the later stages of photosynthesis.
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T5
Photosynthesis
Dark Reactions
• This reaction may occur at any time. It does not
need light.
• Stored chemical energy made during the light
reaction is used to change carbon dioxide to
carbohydrates (sugars).
Model Agricultural Core Curriculum: Supplement
University of California, Davis
318.T6