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dc.contributor.authorSalehian, Omid.en_US
dc.date.accessioned2009-10-02T13:19:57Z
dc.date.available2009-10-02T13:19:57Z
dc.date.issued1991-10-02T13:19:57Z
dc.identifier.urihttp://hdl.handle.net/10464/2746
dc.description.abstractPhotosynthetic state transitions were investigated in the cyanobacterium Synechococcus sp. PCC 6301 by studying fluorescence emission, heat loss, and PS I activity in intact cells brought to state 1 and state 2. 77K fluorescence emission spectra were modelled with a sum of 6 components corresponding to PBS, PS II, and PS I emissions. The modelled data showed a large decrease in PS II fluorescence accompanied with a small increase in the PS I fluorescence upon transition to state 2 for excitation wavelengths absorbed by both PBS and ChI ll.. The fluorescence changes seen with ChI .a. excitations do not support the predictions of the mobile PBS model of state transition in PBS-containing organisms. Measurements of heat loss from intact cells in the two states were similar for both ChI it. and PBS excitations over three orders of magnitude of laser flash intensity. This suggests that the PBS does not become decoupled from PS II in state 2 as proposed by the PBS detachment model of state transition in PBS-containing organisms. PS I activity measurements done on intact cells showed no difference in the two states, in contrast with the predictions of all of the existing models of state transitions. Based on these results a model for state transition In PBScontaining organisms is proposed, with a PS II photoprotectory function.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectPhotosynthesis.en_US
dc.subjectCyanobacteria.en_US
dc.subjectPlant luminescence.en_US
dc.subjectBacteria, Luminous.en_US
dc.titleDistribution of excitation energy in photosynthesis: a study of heat loss, photo chemical activity and fluorescence emission in intact calls of cyanobacterium.en_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.nameM.Sc. Biological Sciencesen_US
dc.degree.levelMastersen_US
dc.contributor.departmentDepartment of Biological Sciencesen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US


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