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 Electron Transport Chain01:30

The Electron Transport Chain

13.8K
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...
13.8K
Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

6.8K
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...
6.8K
Enzyme Inhibition01:30

Enzyme Inhibition

72.5K
Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
72.5K
Feedback Inhibition00:46

Feedback Inhibition

44.1K
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!
44.1K
Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

9.1K
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
9.1K
Enzymes02:34

Enzymes

69.1K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
69.1K

You might also read

Related Articles

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

Sort by
Same author

Verification of lifetime and mechanical load aspects for ITER diagnostic pressure gauges based on ZrC emitter.

The Review of scientific instruments·2024
Same author

Search for Lepton Number and Flavor Violation in K^{+} and π^{0} Decays.

Physical review letters·2021
Same author

Fungal Planet description sheets: 716-784.

Persoonia·2018
Same author

Novel Way to Search for Light Dark Matter in Lepton Beam-Dump Experiments.

Physical review letters·2018
Same author

PDGF-BB regulates splitting angiogenesis in skeletal muscle by limiting VEGF-induced endothelial proliferation.

Angiogenesis·2018
Same author

Fusarium riograndense sp. nov., a new species in the Fusarium solani species complex causing fungal rhinosinusitis.

Journal de mycologie medicale·2018
Same journal

Energy quenching via triplet-excited state formation of glycosylated carotenoids in the photosynthetic reaction center complex of the green sulfur bacterium Chlorobaculum tepidum.

Photosynthesis research·2026
Same journal

Quantitative phosphoproteomics profiling reveals the regulatory mechanisms underlying high light stress in maize and rice.

Photosynthesis research·2026
Same journal

Siphonous green macroalgae with contrasting capacities for the energy-dependent quenching, qE, rely on different photoprotective mechanisms.

Photosynthesis research·2026
Same journal

On the unidirectionality of electron transfer in reaction centers of Chloroflexus aurantiacus.

Photosynthesis research·2026
Same journal

The contribution of the <sup>240</sup>Ala:Glu:Glu:Thr<sup>243</sup> sequence in the DE-loop of D2 to the acceptor side of Photosystem II.

Photosynthesis research·2026
Same journal

Quick conversions and de novo synthesis within the entire α- and β-carotenoid branches during non-steady-state light transients.

Photosynthesis research·2026
See all related articles

Related Experiment Video

Updated: May 5, 2026

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues
07:10

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues

Published on: February 3, 2023

1.5K

Inhibitor binding to isolated chloroplast cytochrome bf complex.

A B Hope1, P Valente

  • 1School of Biological Sciences, Flinders University, G.P.O. Box 2100, 5001, Adelaide, S.A., Australia.

Photosynthesis Research
|November 26, 2013
PubMed
Summary
This summary is machine-generated.

Three inhibitors of quinol oxidation block electron transfer in the chloroplast cytochrome bf complex. This inhibition enhances Photosystem I (PSI) and plastocyanin (PC) oxidation, impacting electron flow and complex formation.

More Related Videos

Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors
10:33

Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors

Published on: October 26, 2015

10.9K
A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
08:04

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

Published on: March 13, 2014

11.5K

Related Experiment Videos

Last Updated: May 5, 2026

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues
07:10

Purification of Active Photosystem I-Light Harvesting Complex I from Plant Tissues

Published on: February 3, 2023

1.5K
Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors
10:33

Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors

Published on: October 26, 2015

10.9K
A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
08:04

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

Published on: March 13, 2014

11.5K

Area of Science:

  • Biochemistry
  • Photosynthesis Research
  • Plant Molecular Biology

Background:

  • The chloroplast cytochrome bf complex is crucial for electron transport during photosynthesis.
  • Quinol oxidation is a key step in the electron transfer pathway mediated by the cytochrome bf complex.
  • Specific inhibitors can probe the function and mechanisms of this complex.

Purpose of the Study:

  • To investigate the effects of three quinol oxidation inhibitors (stigmatellin, tridecylstigmatellin, dibromothymoquinone) on the isolated cytochrome bf complex.
  • To elucidate the mechanism of electron transfer between the Rieske center (FeS), cytochrome f, and plastocyanin (PC).
  • To understand how inhibitors affect electron transfer rates, equilibrium coefficients, and complex formation.

Main Methods:

  • Utilized an isolated system with Photosystem I (PSI) particles, plastocyanin (PC), and the cytochrome bf complex.
  • Employed laser flash photolysis to induce oxidation of P700 and PC.
  • Simulated reaction kinetics using rate coefficients with and without inhibitor binding to the bf complex.

Main Results:

  • Inhibitors increased cytochrome f oxidation and slightly decreased PC oxidation after laser-induced P700 oxidation.
  • Re-reduction of oxidized P700 was more complete in the presence of inhibitors.
  • Inhibitors blocked electron transfer from the Rieske center (FeS) to cytochrome f and PC, increasing the cytochrome f/PC reaction equilibrium coefficient.

Conclusions:

  • The Rieske center (FeS) donates electrons to cytochrome f and PC with a rate coefficient of 35 s(-1) in the absence of inhibitors.
  • Inhibitors increase the equilibrium coefficient for the cytochrome f/PC reaction by decreasing the back reaction rate.
  • Inhibitors promote the formation of transient complexes between P700, PC, and the bf complex, significantly altering redox potentials.