Note:  these are known as the LIGHT DEPENDANT reactions of photosynthesis.
C. Converting the energy from ATP and NADPH into glucose from CO2 and H2O.
(These reactions are known as the LIGHT INDEPENDANT reactions of photosynthesis)


The summary equation of photosynthesis is:
 6 CO2 + 12 H2O + Light Energy --------> C6H12O6 (glucose) + 6 H2O + 6 O2
V. LIGHT - light is composed of subatomic particles called PHOTONS.  Photons always move at the same speed (light-speed) and travel in waves.  The distance from peak to peak of the waves are known as a WAVELENGTH.  The shorter the wavelength, the the higher the energy.

B. Electromagnetic Spectrum  - The entire spectrum of photon radiation.

Photosynthesis uses the visible light portion of the spectrum to work. 

C. Pigments - are chemicals that absorb a portion of the visible spectrum.  There are 4 pigments that are used by plants to absorb light:
   1. Chlorophyll A - reflects green
   2. Chlorophyll B - reflects yellow/green
   3. Xanthophyll - reflects red
   4. Carotene - reflects orange/yellow

Xanthophyll and Carotene together are known as the carotenoids.
 Together these 4 pigments work to absorb the majority of the high energy, short wavelength portion (violet, blue) of the spectrum.

Fall colors occur because the Chlorophylls denature 1st when the plant leaf cells stop photosynthesizing and the carotenoids  break down later so the leaf will turn yellow ----> red.