The Iron and Magnesium Branches of the Porphyrin Biosynthetic Pathway - Chlorophyll Biosynthesis and Technological Applications - page 185

Fig. 6.4 Monocarboxylic monovinyl Chl a and b biosynthetic routes of DMV-LDV-DLMV
plants (Adapted from Kolossov and Rebeiz 2010 ). The new biosynthetic routes labeled 0 0 was
called for by the discovery of 4VMpeR and 4VCR activity in barley chloroplasts. All other routes
are numbered as described in Rebeiz et al. ( 2003 ). D reaction occurring in darkness. All
abbreviations are as in Rebeiz et al. ( 2003 )
interaction between donor and acceptor and does not involve the exchange of a
photon. The rate of energy transfer depends upon (a) the extent of overlap of
the emission spectrum of the donor and the absorption spectrum of the acceptor,
(b) the relative orientation of the donor and acceptor transition dipoles, and (c) the
distance between donor and acceptor molecules. As soon as the excited donor “D*”
and unexcited acceptor “A” states are coupled by an appropriate interaction, they
become degenerate if there is an excited state of the acceptor “A”, which requires
exactly the same excitation energy available in “D*”. When such a condition exists,
excitation of one of the degenerate states leads to a finite probability that the same
excitation will appear in the other degenerate state (Turro 1965 ). This probability
increases with time but is inversely proportional to the sixth power of the fixed