Brent Cornell

    
Pigments absorb light as a source of energy for photosynthesis

• The absorption spectrum indicates the wavelengths of light absorbed by each pigment (e.g. chlorophyll)
• The action spectrum indicates the overall rate of photosynthesis at each wavelength of light

There is a strong correlation between the cumulative absorption spectra of all pigments and the action spectrum

• Both display two main peaks – a larger peak at the blue region (~450 nm) and a smaller peak at the red region (~670 nm) 
• Both display a trough in the green / yellow portion of the visible spectra (~550 nm)

Absorption and Action Spectra

Select Spectrum



Absorption spectrum



Action spectrum



Absorption + Action Spectra