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A viewpoint: Why chlorophyll a?

Björn, Lars Olof LU ; Papageorgiou, George C.; Blankenship, Robert E. and Govindjee, [unknown] (2009) In Photosynthesis Research 99(2). p.85-98
Abstract
Chlorophyll a (Chl a) serves a dual role in

oxygenic photosynthesis: in light harvesting as well as in

converting energy of absorbed photons to chemical energy.

No other Chl is as omnipresent in oxygenic photosynthesis

as is Chl a, and this is particularly true if we include Chl a2,

(=[8-vinyl]-Chl a), which occurs in Prochlorococcus, as a

type of Chl a. One exception to this near universal pattern

is Chl d, which is found in some cyanobacteria that live in

filtered light that is enriched in wavelengths [700 nm.

They trap the long wavelength electronic excitation, and

convert it into chemical energy. In this Viewpoint, we have

traced the... (More)
Chlorophyll a (Chl a) serves a dual role in

oxygenic photosynthesis: in light harvesting as well as in

converting energy of absorbed photons to chemical energy.

No other Chl is as omnipresent in oxygenic photosynthesis

as is Chl a, and this is particularly true if we include Chl a2,

(=[8-vinyl]-Chl a), which occurs in Prochlorococcus, as a

type of Chl a. One exception to this near universal pattern

is Chl d, which is found in some cyanobacteria that live in

filtered light that is enriched in wavelengths [700 nm.

They trap the long wavelength electronic excitation, and

convert it into chemical energy. In this Viewpoint, we have

traced the possible reasons for the near ubiquity of Chl a

for its use in the primary photochemistry of Photosystem II

(PS II) that leads to water oxidation and of Photosystem I

(PS I) that leads to ferredoxin reduction. Chl a appears to

be unique and irreplaceable, particularly if global scale

oxygenic photosynthesis is considered. Its uniqueness is

determined by its physicochemical properties, but there is

more. Other contributing factors include specially tailored

protein environments, and functional compatibility with

neighboring electron transporting cofactors. Thus, the same

molecule, Chl a in vivo, is capable of generating a radical

cation at ?1 V or higher (in PS II), a radical anion at -1 V

or lower (in PS I), or of being completely redox silent (in

antenna holochromes). (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Photosystem II, Evolution of photosystems _ Oxygenic photosynthesis, Color of plants, Cyanobacteria, Chlorophylls in proteins, Chlorophyll a, Chlorophyll d, Reaction centers, Chemistry of chlorophylls, Photosystem I, Spectra of chlorophylls
in
Photosynthesis Research
volume
99
issue
2
pages
85 - 98
publisher
Springer
external identifiers
  • wos:000263544900002
  • scopus:66849101268
ISSN
0166-8595
DOI
10.1007/s11120-008-9395-x
project
Photobiology
language
English
LU publication?
yes
id
fd738745-ecbd-4577-b3cb-4d0f802b0529 (old id 1287927)
date added to LUP
2009-04-29 13:11:58
date last changed
2017-11-19 03:32:43
@article{fd738745-ecbd-4577-b3cb-4d0f802b0529,
  abstract     = {Chlorophyll a (Chl a) serves a dual role in<br/><br>
oxygenic photosynthesis: in light harvesting as well as in<br/><br>
converting energy of absorbed photons to chemical energy.<br/><br>
No other Chl is as omnipresent in oxygenic photosynthesis<br/><br>
as is Chl a, and this is particularly true if we include Chl a2,<br/><br>
(=[8-vinyl]-Chl a), which occurs in Prochlorococcus, as a<br/><br>
type of Chl a. One exception to this near universal pattern<br/><br>
is Chl d, which is found in some cyanobacteria that live in<br/><br>
filtered light that is enriched in wavelengths [700 nm.<br/><br>
They trap the long wavelength electronic excitation, and<br/><br>
convert it into chemical energy. In this Viewpoint, we have<br/><br>
traced the possible reasons for the near ubiquity of Chl a<br/><br>
for its use in the primary photochemistry of Photosystem II<br/><br>
(PS II) that leads to water oxidation and of Photosystem I<br/><br>
(PS I) that leads to ferredoxin reduction. Chl a appears to<br/><br>
be unique and irreplaceable, particularly if global scale<br/><br>
oxygenic photosynthesis is considered. Its uniqueness is<br/><br>
determined by its physicochemical properties, but there is<br/><br>
more. Other contributing factors include specially tailored<br/><br>
protein environments, and functional compatibility with<br/><br>
neighboring electron transporting cofactors. Thus, the same<br/><br>
molecule, Chl a in vivo, is capable of generating a radical<br/><br>
cation at ?1 V or higher (in PS II), a radical anion at -1 V<br/><br>
or lower (in PS I), or of being completely redox silent (in<br/><br>
antenna holochromes).},
  author       = {Björn, Lars Olof and Papageorgiou, George C. and Blankenship, Robert E. and Govindjee, [unknown]},
  issn         = {0166-8595},
  keyword      = {Photosystem II,Evolution of photosystems _ Oxygenic photosynthesis,Color of plants,Cyanobacteria,Chlorophylls in proteins,Chlorophyll a,Chlorophyll d,Reaction centers,Chemistry of chlorophylls,Photosystem I,Spectra of chlorophylls},
  language     = {eng},
  number       = {2},
  pages        = {85--98},
  publisher    = {Springer},
  series       = {Photosynthesis Research},
  title        = {A viewpoint: Why chlorophyll a?},
  url          = {http://dx.doi.org/10.1007/s11120-008-9395-x},
  volume       = {99},
  year         = {2009},
}