Transient absorption studies of the primary charge separation in photosystem II

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp951984v· OSTI ID:199381

Donovan, B; Walker, II, L A; Yocum, C F; Sension, R J ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States)

Femtosecond transient absorption studies of the primary charge separation in photosystem II (PSII) are presented. A careful study of the dependence of the observed signal on laser intensity demonstrates that the multiple excitation of reaction centers produces additional fast components not observed at low excitation energy. In the regime where the observed signals are linear with excitation energy, a 20 {+-} 2 ps rise of the pheophytin anion absorption, bleach of the pheophytin Q{sub {chi}} absorption, and appearance of the chlorophyll cation absorption are observed. Three different protocols, involving varying exposure of the PSII complex to the detergent Triton X-100, are used to prepare D1-D2-cyt b{sub 559} complexes from spinach. The kinetic signals are independent of the method of sample preparation. 35 refs., 5 figs.

• OSTI ID: 199381
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 5 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
40 CHEMISTRY
55 BIOLOGY AND MEDICINE
BASIC STUDIES
ABSORPTION SPECTRA
CATIONS
CHARGE TRANSPORT
LASER RADIATION
ORGANIC COMPOUNDS
PHOTOSYNTHESIS
PHOTOSYNTHETIC BACTERIA
PHOTOSYNTHETIC REACTION CENTERS