Linked Life Data

6772210

Source:http://linkedlifedata.com/resource/pubmed/id/6772210

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1980-10-27
pubmed:abstractText
In the absence of electron acceptors and of oxygen a proton gradient was supported across thylakoid membranes of intact spinach chloroplasts by far-red illumination. It was decreased by red light. Inhibition by red light indicates effective control of cyclic electron flow by Photosystem II. Inhibition was released by oxygen which supported a large proton gradient. Oxygen appeared to act as electron acceptor simultaneously preventing over-reduction of electron carriers of the cyclic electron transport pathway. It thus has an important regulatory function in electron transport. Under anaerobic conditions, the inhibition of electron transport caused by red illumination could also be released and a large proton gradient could be established by oxaloacetate, nitrite and 3-phosphoglycerate, but not by bicarbonate. In the absence of oxygen, ATP levels remained low in chloroplasts illuminated with red light even when bicarbonate was present. They increased when electron acceptors were added which could release the over-reduction of the electron transport chain. Inhibition of electron transport in the presence of bicarbonate was relieved and CO2-fixation was initiated by oxygen concentrations as low as about 10 microM. Once CO2 fixation was initiated, very low oxygen levels were sufficient to sustain it. The results support the assumption that pseudocyclic electron transport is necessary to poise the electron transport chain so that a proper balance of linear and cyclic electron transport is established to supply ATP for CO2 reduction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
591
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
266-74
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
Oxygen requirement of photosynthetic CO2 assimilation.
pubmed:publicationType
Journal Article