Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Photochemical Reaction Center01:29

The Photochemical Reaction Center

Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
Photosystem II01:22

Photosystem II

The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across  two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Photosystem I01:27

Photosystem I

Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
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...
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
The Antenna Complex01:15

The Antenna Complex

Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
The Z-Scheme of Electron Transport in Photosynthesis01:34

The Z-Scheme of Electron Transport in Photosynthesis

The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Structural Engineering of Cyanine Dyes to Access Shortwave Infrared-Emissive J-Aggregates.

Journal of the American Chemical Society·2026
Same author

Silicon Flavylium Polymethine Dyes for Shortwave Infrared Imaging.

Journal of the American Chemical Society·2026
Same author

Stochastic<i>GW</i>-GPU: Rapid Quasi-Particle Energies for Molecules beyond 10,000 Atoms.

Journal of chemical theory and computation·2026
Same author

Phase Space Electronic Structure Theory: From Diatomic Lambda-Doubling to Macroscopic Einstein-de Haas.

The journal of physical chemistry letters·2026
Same author

Erratum: "A basis-free phase space electronic Hamiltonian that recovers beyond Born-Oppenheimer electronic momentum and current density" [J. Chem. Phys. 162, 144111 (2025)].

The Journal of chemical physics·2025
Same author

Conical Intersections and Electronic Momentum as Viewed from Phase Space Electronic Structure Theory.

The journal of physical chemistry letters·2025

Related Experiment Video

Updated: May 8, 2026

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
08:40

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting

Published on: February 14, 2019

Environment-Induced Exciton Renormalization in the Photosystem II Reaction Center.

Tucker Allen1, Barry Y Li1, Nadine C Bradbury2

  • 1Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States.

Journal of Chemical Theory and Computation
|May 6, 2026
PubMed
Summary

We developed a new quantum method to simulate how protein environments affect light-harvesting in Photosystem II reaction centers (PSII-RC). This computational advance allows accurate modeling of complex biological systems.

More Related Videos

Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
10:20

Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses

Published on: August 9, 2019

Related Experiment Videos

Last Updated: May 8, 2026

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
08:40

Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting

Published on: February 14, 2019

Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses
10:20

Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses

Published on: August 9, 2019

Area of Science:

  • Quantum biology
  • Computational biophysics
  • Photosynthesis research

Background:

  • Protein electrostatics significantly influence excitation energies in Photosystem II reaction centers (PSII-RC).
  • Accurate quantum-mechanical, many-body descriptions of protein-environment renormalization of excitons were computationally challenging.
  • The Bethe-Salpeter equation (BSE) offers accurate excitonic physics but is computationally expensive for large systems.

Purpose of the Study:

  • To develop and apply a computationally tractable many-body approach for studying exciton dynamics in biological nanostructures.
  • To investigate the role of the protein environment on the electronic and excitonic properties of the PSII-RC.
  • To enable *ab initio* studies of large, complex biological systems using advanced quantum mechanical methods.

Main Methods:

  • Application of stochastic sampling techniques to simplify the Bethe-Salpeter equation (BSE) for large systems.
  • Development of a computational framework for *ab initio* study of the PSII-RC, including the hexameric dye core and local protein environment.
  • Comparison of optical excitations between isolated chromophore hexamers and protein-dye clusters.

Main Results:

  • The BSE becomes computationally feasible for large systems using stochastic sampling, revealing collective *k*-dependent polarization effects.
  • The study modeled the PSII-RC with explicit treatment of six chlorins and a ~7 Å protein environment.
  • Inclusion of the protein environment caused polarization-dependent shifts, altered spectral weight, and modified exciton delocalization and pigment character for Qy excitations.

Conclusions:

  • Stochastic sampling techniques make the BSE tractable for large biological systems, enabling accurate quantum mechanical calculations.
  • The protein environment significantly impacts the optical and excitonic properties of the PSII-RC.
  • This work establishes a powerful computational tool for many-body calculations of biological nanostructures.