Читать книгу Molecular Mechanisms of Photosynthesis - Robert E. Blankenship - Страница 67

Bacteriochlorophyll b is found only in a few species of purple bacteria. It differs from bacteriochlorophyll a only by the presence of an exocyclic double bond at C‐8 in ring B, which is called an ethylidine substituent. Its chemical structure is shown in Fig. 4.4. Bacteriochlorophyll b has the longest‐wavelength absorbance band of any known chlorophyll‐type pigment. in vivo, its absorbance maximum is at 960–1050 nm.