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

3.2K
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...
3.2K
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

19.5K
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...
19.5K
Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

9.7K
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...
9.7K
Electron Transport Chains01:28

Electron Transport Chains

116.2K
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...
116.2K
The Electron Transport Chain01:30

The Electron Transport Chain

21.4K
The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q...
21.4K
Electron Transport Chain Components01:29

Electron Transport Chain Components

1.2K
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...
1.2K

You might also read

Related Articles

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

Sort by
Same author

Cryo-EM structures of naturally occurring dimeric photosystem II complexes lacking the Mn<sub>4</sub>CaO<sub>5</sub> cluster.

Nature communications·2026
Same author

Structure of E. coli twin-arginine translocase (Tat) complex with bound cargo.

Molecular cell·2026
Same author

In situ structure of bacterial 50S ribosomes at 3.0 Å resolution from vitreous sections.

Communications biology·2025
Same author

Author Correction: SCAF1 drives the compositional diversity of mammalian respirasomes.

Nature structural & molecular biology·2025
Same author

The Arthropoda-specific Tramtrack group BTB protein domains use previously unknown interface to form hexamers.

eLife·2024
Same author

SCAF1 drives the compositional diversity of mammalian respirasomes.

Nature structural & molecular biology·2024

Related Experiment Video

Updated: Mar 26, 2026

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
05:27

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools

Published on: July 20, 2022

2.3K

Structure of bacterial respiratory complex I.

John M Berrisford1, Rozbeh Baradaran2, Leonid A Sazanov3

  • 1European Bioinformatics Institute, Cambridge CB10 1SD, UK.

Biochimica Et Biophysica Acta
|January 26, 2016
PubMed
Summary

Complex I, crucial for cellular energy, is a large redox enzyme. Its structure reveals the electron transfer pathway and proton translocation channels, offering insights into energy production and disease mechanisms.

Keywords:
Complex IElectron transferMembrane proteinProton translocationRespiratory chainX-ray crystallography

More Related Videos

Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease
05:45

Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease

Published on: May 3, 2024

2.2K
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

14.9K

Related Experiment Videos

Last Updated: Mar 26, 2026

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
05:27

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools

Published on: July 20, 2022

2.3K
Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease
05:45

Author Spotlight: Unveiling Oxidative Phosphorylation System Dynamics and Mitochondrial Roles in Health and Disease

Published on: May 3, 2024

2.2K
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

14.9K

Area of Science:

  • Biochemistry
  • Structural Biology
  • Cellular Respiration

Background:

  • Complex I (NADH:ubiquinone oxidoreductase) is essential for cellular energy production via redox reactions.
  • It is the largest protein complex in respiratory chains, with bacterial versions serving as minimal models.
  • Mitochondrial Complex I dysfunction is linked to neurodegenerative diseases.

Purpose of the Study:

  • To elucidate the structure and mechanism of Complex I.
  • To provide structural insights into the electron transfer pathway and proton translocation.
  • To understand the coupling mechanism between redox energy and proton pumping.

Main Methods:

  • X-ray crystallography was used to determine the structures of Complex I domains and the intact complex.
  • Structural analysis focused on the hydrophilic and membrane domains, including electron transfer pathways and proton channels.

Main Results:

  • Crystal structures of hydrophilic and membrane domains, and the entire Complex I from Thermus thermophilus were solved.
  • A detailed 95Å electron transfer pathway from flavin mononucleotide through iron-sulfur clusters to the quinone-binding site was identified.
  • Four proton translocation channels were found in the membrane domain, linked by a charged flexible axis.

Conclusions:

  • The solved structures provide a detailed view of Complex I's architecture and function.
  • The findings offer insights into the mechanism of redox energy coupling to proton translocation.
  • Understanding Complex I structure is vital for research into energy production and associated diseases.