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

Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
Anoxygenic Photosynthesis01:30

Anoxygenic Photosynthesis

Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green sulfur bacteria, heliobacteria, and...
Carbon-dioxide Fixation01:28

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
Oxygenic Photosynthesis01:26

Oxygenic Photosynthesis

Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate light...
The Supercomplexes in the Crista Membrane01:41

The Supercomplexes in the Crista Membrane

The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through respiratory complexes I to V. These complexes have been widely studied for decades, and it has been proven that they form supramolecular structures called respiratory supercomplexes (SC). These higher-order complexes may be crucial in maintaining the biochemical structure and improving the physiological activity of the individual complexes while...
Electron Transport Chains01:28

Electron Transport Chains

The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...

You might also read

Related Articles

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

Sort by
Same author

Improving the Aroma of Millets by Targeting the <i>Betaine Aldehyde Dehydrogenase 2</i> Gene: A Promising Approach for Popularising Millet Foods Worldwide.

Current genomics·2026
Same author

Enhancing CRISPR/Cas-Mediated Gene Knockout With Short Non-Homologous Oligonucleotides.

Plant biotechnology journal·2026
Same author

Correction to: Estimating the redox state of the plastoquinone pool in algae and cyanobacteria via OJIP fluorescence: perspectives and limitations.

Photosynthesis research·2026
Same author

Estimating the redox state of the plastoquinone pool in algae and cyanobacteria via OJIP fluorescence: perspectives and limitations.

Photosynthesis research·2026
Same author

Lipid assemblies mediating the fusion of photosystem-II enriched membranes characterized by DPH (1,6-diphenyl-1,3,5-hexatriene) fluorescence and fluorescence anisotropy lifetimes.

Journal of photochemistry and photobiology. B, Biology·2026
Same author

Revisiting the Q<sub>A</sub> model of chlorophyll-a fluorescence induction: new perspectives to monitor the photochemical activity and structural dynamics of photosystem II.

Photosynthesis research·2025

Related Experiment Video

Updated: Jun 26, 2026

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes
10:27

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Published on: May 4, 2018

Experimental evidence for ascorbate-dependent electron transport in leaves with inactive oxygen-evolving complexes.

Szilvia Z Tóth1, Jos T Puthur, Valéria Nagy

  • 1Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, H-6701 Szeged, Hungary. sztoth@brc.hu

Plant Physiology
|January 16, 2009
PubMed
Summary

Ascorbate serves as a vital alternative electron donor to Photosystem II (PSII) in heat-stressed plants, supporting electron transport when oxygen-evolving complexes are inactivated. This finding highlights ascorbate

More Related Videos

Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana
09:54

Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana

Published on: January 5, 2018

A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
11:56

A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells

Published on: April 11, 2014

Related Experiment Videos

Last Updated: Jun 26, 2026

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes
10:27

Measuring Trans-Plasma Membrane Electron Transport by C2C12 Myotubes

Published on: May 4, 2018

Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana
09:54

Isolation and Respiratory Measurements of Mitochondria from Arabidopsis thaliana

Published on: January 5, 2018

A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
11:56

A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells

Published on: April 11, 2014

Area of Science:

  • Plant Physiology
  • Photosynthesis Research
  • Molecular Biology

Background:

  • Photosystem II (PSII) normally relies on oxygen-evolving complexes for electron donation.
  • In heat-stressed plants, oxygen-evolving complexes can be inactivated, necessitating alternative electron donors.
  • Previous in vitro studies suggested ascorbate as a potential in vivo electron donor, but this remained unconfirmed.

Purpose of the Study:

  • To investigate the in vivo role of ascorbate as an alternative electron donor to PSII in heat-treated plants.
  • To determine the dependency of electron transport on ascorbate levels in Arabidopsis thaliana.
  • To elucidate the mechanism of ascorbate-mediated electron transfer to PSII.

Main Methods:

  • Utilized chlorophyll a fluorescence and 820-nm absorbance transient measurements on wild-type and ascorbate-deficient (vtc2-1) Arabidopsis leaves.
  • Performed thermoluminescence measurements to assess the involvement of Tyr(Z)(+) in electron transfer.
  • Compared electron transport rates in heat-treated and tris(hydroxymethyl)aminomethane-treated thylakoid membranes.

Main Results:

  • Electron donation to PSII and electron transport to PSI were dependent on leaf ascorbate content in heat-treated plants.
  • Ascorbate treatment significantly decreased electron donation half-times in both wild-type and mutant leaves.
  • Thermoluminescence indicated Tyr(Z)(+) mediates electron transfer from ascorbate to PSII, supporting sustained electron transport.

Conclusions:

  • Ascorbate functions in vivo as an alternative electron donor to PSII in plants with inactivated oxygen-evolving complexes.
  • This alternative electron transport pathway is widespread in the plant kingdom and influenced by physiological and environmental factors.
  • Ascorbate plays a crucial physiological role in heat-stressed plants by maintaining electron transport activity.