(flopmaster) wrote in message . com...
Hi.

Looking at a graph of light absorption, chlorophyll (a+b) appear to
absorb at a peak of 642 and 662 nm in the red region.

I'd guess that the action-spectrum would show maximum action at some
point between these two wavelengths, however the graph I have shows
the peak activity at around 690nm. What's the deal?

If you had to use a red light with one specific wavelength, what would
it be?

Thanks.

Accessory pigments. Chlorophyll a and b are not the only pigments
involved in capturing photons, and the process is not so simple as
direct absorption of a photon by a cholorphyll molecule. There's a
useful discussion, including a description of the Emerson effect, at
http://www.biologie.uni-hamburg.de/b-online/e24/24c.htm

If you were forced to use a single wavelength of light, it would be
somewhere between 670 and 700 nm; but the Emerson effect predicts far
better results with two wavelengths together, especially 670 and 700
nm.

--
Chris Green