PART I: LIGHT-ABSORBING PIGMENTS
Sunlight is “white” light composed of all the wavelengths (colors) of the visible spectrum: red-orange- yellow-green-blue-indigo-violet (or “Roy G. Biv.”). Photosynthesis begins with the absorption of sunlight by pigments in the chloroplasts. These pigments absorb some colors of light better than others. For example, a green leaf contains the pigment chlorophyll. The leaf looks green not because chlorophyll absorbs green light, but because it’s molecular bonds absorb all the colors of the spectrum except green. The green light either reflects back to your eye, or passes completely through the leaf and out the other side.. Since chlorophyll can’t absorb any green light, does that mean all the energy in green light goes to waste? Might the leaf contain other pigments that absorb green light? To find out, do Exercise 1.