Bacteriochlorophylls

green pigments produced by photosynthetic purple and green bacteria. They are localized in the chromatophores of the bacterial cell. Most of the purple bacteria contain bacteriochlorophyll a (bacterio-chlorin), which is similar to chlorophyll a of green plants. Certain purple bacteria contain bacteriochlorophyll b. Green bacteria contain bacteriochlorophyll c or bacteriochlorophyll d (bacterioviridins), which differ significantly in structure from other chlorophylls. Every bacteriochlorophyll has its characteristic absorption spectrum. For example, bacteriochlorophyll a has its main absorption maximum at a wave length of 780 nanometers (nm); bacteriochlorophyll b, at 799 nm; bacteriochlorophyll c, at 660 nm; and bacteriochlorophyll d, at 650 nm.