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 Supercomplexes in the Crista Membrane01:41

The Supercomplexes in the Crista Membrane

2.9K
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...
2.9K
Chemiosmosis and ATP Synthesis01:22

Chemiosmosis and ATP Synthesis

1.9K
The electron transport chain is a critical component of cellular respiration, occurring in the inner mitochondrial membrane. It facilitates the transfer of high-energy electrons from reduced cofactors NADH and FADH₂ to molecular oxygen, the final electron acceptor. This transfer of electrons through a series of protein complexes is tightly coupled to the translocation of protons across the membrane, generating a proton gradient essential for ATP synthesis.Electron Flow and Proton...
1.9K
Electron Transport Chain Components01:29

Electron Transport Chain Components

904
The electron transport chain (ETC) is a crucial metabolic pathway that facilitates energy conversion in prokaryotic and eukaryotic cells. In eukaryotes, the ETC comprises four membrane-associated protein complexes in the inner mitochondrial membrane. In prokaryotes, the ETC in the plasma membrane can vary in composition, with fewer or different complexes depending on the organism and environmental conditions. These complexes transfer electrons from electron donors, such as NADH and FADH2, to...
904
Electron Transport Chains01:28

Electron Transport Chains

111.6K
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...
111.6K
Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

9.1K
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...
9.1K
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

18.5K
The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
18.5K

You might also read

Related Articles

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

Sort by
Same author

Molecular and energetic basis of histidine switch dynamics in respiratory complex I.

Protein science : a publication of the Protein Society·2026
Same author

L-type pyocins inhibit the BAM complex to kill without cell entry.

Nature communications·2026
Same author

In situ structure of the human gap junction.

Science advances·2026
Same author

Catalytic relevance of a quinol anion in biological energy conversion by respiratory complex I.

Chemical science·2026
Same author

Dynamic binding of acetogenin-type inhibitors to mitochondrial complex I revealed by photoaffinity labeling.

Biochimica et biophysica acta. Bioenergetics·2025
Same author

Structural basis of respiratory complex adaptation to cold temperatures.

Cell·2024

Related Experiment Video

Updated: Jan 17, 2026

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

18.4K

Proton Transfer through a Charged Conduit in Respiratory Complex I: Long-Range Effects and Conformational Gating.

Luka Simsive1, Oleksii Zdorevskyi1, Vivek Sharma1,2

  • 1Department of Physics, University of Helsinki, Helsinki 00014, Finland.

Journal of Chemical Information and Modeling
|September 18, 2025
PubMed
Summary

Researchers modeled proton transfer in respiratory complex I

More Related Videos

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
07:35

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess

Published on: June 1, 2022

2.6K
Analyzing Supercomplexes of the Mitochondrial Electron Transport Chain with Native Electrophoresis, In-gel Assays, and Electroelution
08:37

Analyzing Supercomplexes of the Mitochondrial Electron Transport Chain with Native Electrophoresis, In-gel Assays, and Electroelution

Published on: June 1, 2017

14.7K

Related Experiment Videos

Last Updated: Jan 17, 2026

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

18.4K
Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
07:35

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess

Published on: June 1, 2022

2.6K
Analyzing Supercomplexes of the Mitochondrial Electron Transport Chain with Native Electrophoresis, In-gel Assays, and Electroelution
08:37

Analyzing Supercomplexes of the Mitochondrial Electron Transport Chain with Native Electrophoresis, In-gel Assays, and Electroelution

Published on: June 1, 2017

14.7K

Area of Science:

  • Bioenergetics
  • Mitochondrial function
  • Protein dynamics

Background:

  • Respiratory complex I is a proton pump vital for cellular energy production.
  • Its internal E channel's role in proton transfer is unclear due to lack of direct evidence in cryo-EM structures.
  • Understanding energy coupling mechanisms is crucial for bioenergetics.

Purpose of the Study:

  • To investigate proton transfer mechanisms within the E channel of respiratory complex I.
  • To elucidate the role of the E channel in proton pumping and energy coupling.
  • To develop a viable model for proton transfer through the E channel.

Main Methods:

  • Hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulations.
  • Free energy calculations using atomistic MD simulations.
  • Analysis of cryo-electron microscopy (cryo-EM) structures of mitochondrial complex I.

Main Results:

  • Identified energetically favorable Grotthuss-competent proton transfer pathways in the E channel.
  • Demonstrated how protonation of distal acidic residues affects E channel proton transfer dynamics.
  • Revealed a gating mechanism involving a conserved tyrosine residue's conformational flipping.

Conclusions:

  • Proposed a stepping-stone model for proton transfer through the E channel.
  • Highlighted the importance of the E channel in bridging the quinone binding site and proton pumping sites.
  • Provided insights into the long-range coupling and gating mechanisms in complex I.