Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 25 (3), 151-60

Photosystem II Heterogeneity: The Acceptor Side

Affiliations

Photosystem II Heterogeneity: The Acceptor Side

Govindjee. Photosynth Res.

Abstract

It is well known that two photosystems, I and II, are needed to transfer electrons from H2O to NADP(+) in oxygenic photosynthesis. Each photosystem consists of several components: (a) the light-harvesting antenna (L-HA) system, (b) the reaction center (RC) complex, and (c) the polypeptides and other co-factors involved in electron and proton transport. First, we present a mini review on the heterogeneity which has been identified with the electron acceptor side of Photosystem II (PS II) including (a) L-HA system: the PS IIα and PS IIβ units, (b) RC complex containing electron acceptor Q1 or Q2; and (c) electron acceptor complex: QA (having two different redox potentials QL and QH) and QB (QB-type; Q'B type; and non-QB type); additional components such as iron (Q-400), U (Em,7=-450 mV) and Q-318 (or Aq) are also mentioned. Furthermore, we summarize the current ideas on the so-called inactive (those that transfer electrons to the plastoquinone pool rather slowly) and active reaction centers. Second, we discuss the bearing of the first section on the ratio of the PS II reaction center (RC-II) and the PS I reaction center (RC-I). Third, we review recent results that relate the inactive and active RC-II, obtained by the use of quinones DMQ and DCBQ, with the fluorescence transient at room temperature and in heated spinach and soybean thylakoids. These data show that inactive RC-II can be easily monitored by the OID phase of fluorescence transient and that heating converts active into inactive centers.

Similar articles

See all similar articles

Cited by 15 PubMed Central articles

See all "Cited by" articles

References

    1. Photosynth Res. 1990 Apr;24(1):35-46 - PubMed
    1. Biochim Biophys Acta. 1979 Jan 11;545(1):188-201 - PubMed
    1. Biochim Biophys Acta. 1979 Apr 11;546(1):93-105 - PubMed
    1. Biochim Biophys Acta. 1981 Mar 12;635(1):105-10 - PubMed
    1. Photosynth Res. 1985 Dec;6(4):295-316 - PubMed
Feedback