1. Photosynthesis Essential Standard
Bio Analyze photosynthesis and cellular respiration in terms of how energy is stored, released, and transferred within the and between these systems.

2. Photosynthesis
Photosynthesis – process by which plants capture energy in light and store it in organic compounds
2 steps:
Light (dependent) reactions
produce chemical energy
Dark (Light independent) reactions
synthesize sugar

3. 1. Light (Dependent)Reactions
Pigments absorb and reflect different colors of light
Visible Light Spectrum – array of colors from splitting a beam of white light
Chlorophyll reflects green light
Plants appear green
Carotenoids are accessory pigments that reflect orange, red, and yellow lights
Autumn Colors!

4. 1. Light (Dependent) Reactions
Light reactions – initial phase of photosynthesis where light energy is transferred into chemical energy.
Chlorophyll
Process:
Sun  Series of Pigments  ATP Synthesis
Photosystem = cluster of pigment molecules that absorb light energy

5. 2. Dark Reactions (Calvin Cycle)
Dark reactions are known as light independent reactions
Calvin Cycle – series of biochemical reactions that produces organic molecules using energy stored in ATP and NADPH
Carbon Fixation  Reduction  Regeneration (sugar)
Carbon Fixation – incorporate CO2 into organic compounds (sugar)
Reduction – incorporating ATP and NADPH to reduce organic compounds
Regeneration – incorporate ATP to “fix” carbohydrates

6. Photosynthesis Equation
Equation for both light dependent and light independent cycles
CO2 + H2O + light energy  Sugar (C6H12O6) + O2

7. Factors that Affect Photosynthesis
Sunlight
Carbon dioxide
Water
Temperature pH