Inactive photosystem II centers: A resolution of discrepencies in photosystem II quantitation

Donald R. Ort, John Whitmarsh

Research output: Contribution to journalLetter


The abundance of photosystem II in chloroplast thylakoid membranes has been a contentious issue because different techniques give quite different estimates of photosystem II titer. This discrepancy led in turn to disagreements regarding the stoichiometry of photosystem II to photosystem I in these membranes. We believe that the discrepancy in photosystem II quantitation is resolved by evidence which shows that a large population of photosystem II centers with negligible turnover rates are present in isolated thylakoid membranes as well as in normally developed leaves of healthy plants.

Original languageEnglish (US)
Pages (from-to)101-104
Number of pages4
JournalPhotosynthesis research
Issue number1
StatePublished - Jan 1 1990



  • Photosystem II
  • heterogeneity
  • plastoquinone
  • spinach thylakoid
  • stoichiometry

ASJC Scopus subject areas

  • Biochemistry
  • Plant Science
  • Cell Biology

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