Related Experiment Video
Updated: Jul 15, 2026

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
Published on: March 13, 2014
Macromolecular crowding and its influence on possible reaction mechanisms in photosynthetic electron flow
I G Tremmel1, E Weis, G D Farquhar
1Max-Planck-Institute for Biophysical Chemistry, Theoretical and Computational Biophysics Department, Am Fassberg 11, D-37077 Goettingen, Germany. ira@germanynet.de
Abstract:
The diffusion of plastoquinol and its binding to the Qo site of the cyt bf complex in the course of photosynthetic electron transport was studied by following the sigmoidal flash-induced re-reduction kinetics of P700 after previous oxidation of the intersystem electron carriers. The data resulting from these experiments were matched with a simulation of electron transport using Monte Carlo techniques. The simulation was able to account for the experimental observations. Two different extreme cases of reaction mechanism at the Qo site were compared: a diffusion limited collisional mechanism and a non-diffusion limited tight binding mechanism. Assuming a tight binding mechanism led to best matches due to the high protein density in thylakoids. The varied parameters resulted in values well within the range of published data. The results emphasise the importance of structural characteristics of thylakoids in models of electron transport.
More Related Videos
06:39Analysis of Protein Complex Formation at Micromolar Concentrations by Coupling Microfluidics with Mass Photometry
Published on: January 26, 2024
08:40Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
Published on: February 14, 2019
Related Concept Videos
The Z-Scheme of Electron Transport in Photosynthesis
The Antenna Complex
The Photochemical Reaction Center
Photosystem I
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Photosystem II
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Oxygenic Photosynthesis