|
| |
| | Thiobacillus ferrooxidans |
 | | In subsequent cycles, hydroquinone would be reduced by one electron from the Rieske center and one electron from heme bL (the electron transfer between reduced heme bL and quinone being thermodynamically favorable). | | | The electron transfer between the two b-hemes would be facilitated by their close midpoint potential values at acidic pH. | | | Their organisation into an electron transport chain bridging the span from Fe(II) to the membrane-bound, energy conserving electron transport pathways is still a matter of debate. |
|
http://bip.cnrs-mrs.fr/bip09/tb.html
(1527 words)
|
|
| |
| | abstr7.html |
| | In this study, the turnover time of the electron transfer chain is defined as a function of the relative concentration of D1 protein in reaction centre II and the photoinhibition processes due to D1 protein degradation are incorporated into a model of photosynthesis, initiated by Dubinsky et al. | | | Recent evidence from algal physiology and molecular biology confirms that photoinhibition is directly related to D1 protein damage and recovery, and D1 protein damage leads to a decrease in electron transfer or an increase in turnover time of the electron transfer chain. | | | Abstract: Recent evidence from algal physiology and molecular biology confirms that photoinhibition is directly related to D1 protein damage and recovery, and D1 protein damage leads to a decrease in electron transfer or an increase in turnover time of the electron transfer chain. |
|
http://www.entu.cas.cz/dtb/abstract/abstr7.html
(480 words)
|
|
| |
| | CyberEd® PLATO Science :: Science Education Software |
| | Students view a simple animation of the electron transfer chain (ETC) that shows the transfer of electrons from reduced NAD and reduced FAD to successive electron carriers in the mitochondrial membrane, and their final acceptance by oxygen. | | | Describe how the reduced coenzymes NAD and FAD carry hydrogen ions, electrons and their associated energy from the intermediates of the respiratory pathway to the electron transfer chain. | | | State the location within a mitochondrion of the electron acceptors of the electron transfer chain. |
|
http://www.cybered.net/commerce.asp?CatId=310&ProdId=X5002112
(445 words)
|
|
| |
| | looking for electron transport chain |
| | The electron transport chain couples the transfer of an electron from NADH to molecular oxygen (O2) with the pumping of protons (H+) across a membrane. | | | Electron Transport Chain The electron transport chain is located predominantly in the: A. Outer membrane of the mitochondria B. Intermembrane space of the mitochondria C. Inner membrane of the... | | | Electron Transport Chain Definition: Biomolecular machinery present in prokaryotic membranes and eukaryotic mitochnodria that couples the flow of electrons to proton pumps in order to convert energy... |
|
http://www.foto-ophelia.de/electron_transport_chain.html
(315 words)
|
|
| |
| | More Basic Plant Cytology |
| | The genes in this DNA code for some of the critical enzymes and electron transfer proteins needed for the Kreb's cycle and the electron transfer chain which are translated on mitochondrial ribosomes. | | | While they may be more round than oval in shape, plant mitochondria carry out the Kreb's cycle in the matrix and operate the electron transfer chain in the infolded cristae of the inner membrane. | | | The electron transfer proteins of the light reactions pump protons into the thylakoid lamellae; the protons pass back through ATP synthases of the thylakoid membrane on their way back to the stroma; this results in ATP synthesis as in mitochondria. |
|
http://koning.ecsu.ctstateu.edu/Plant_Physiology/basiccytology2.html
(1497 words)
|
|
| |
| | Gordon Research Conference on ELECTRON DONOR ACCEPTOR INTERACTIONS |
| | Michael Elliott - A direct experimental comparison of the electron transfer theories of Marcus and Hush: studies of the optical and thermal intramolecular electron transfer in a mixed-valent dinuclear iron polypyridyl complex | | | Thomas A. Moore (with Devens Gust and Ana L. Moore) - Photoinduced Electron Transfer Coupled to the Generation of Proton Motive Force and the Synthesis of ATP in an Artificial Photosynthetic Membrane | | | Tiaquan (Tim) Lian - Femtosecond IR study of electron transfer between semiconductor nanostructures and molecular adsorbates |
|
http://www.grc.uri.edu/programs/1998/elecdono.htm
(399 words)
|
|
| |
| | Electron transfer |
| | electron electron configuration electron transport electron tube electron volt thermo electron electron beam electron transport chain electron microscopy sciences laser marking electron electron beam welding marking electron beam thermo electron corporation | | | LEO Electron Microscopy Manufacturers of scanning electron microscopes and transmission electron microscopes. | | | Lionel's Acorn Electron Pages Photograph and description of an Electron with a Jafa Mode 7 unit, Slogger RomBox, Acorn Plus 1, ACP Advanced Plus 4, and 2 Sideways RAM expansions. |
|
http://www.serebella.com/encyclopedia/article-Electron_transfer.html
(326 words)
|
|
| |
| | Dianne K. Newman |
| | We are using biochemical, genetic, and physiological approaches to determine where in the cell phenazines are reduced, how they interface with the membrane-bound electron transfer chain, what genes are activated in their presence, and whether cells that produce them gain energy (for growth or maintenance) from their production and/or recycling. | | | Unlike most terminal electron acceptors that bacteria use for respiration (which are soluble and readily make their way to the cell to receive electrons from the membrane-bound molecules of the respiratory chain), ferric (hydr)oxide minerals are essentially insoluble under most environmental conditions. | | | Although my group has focused on electron shuttling in the context of mineral reduction, this is only one example in which extracellular electron transfer may be important. |
|
http://www.hhmi.org/research/investigators/newman.html
(1041 words)
|
|
| |
| | Stephen L. Gipson |
| | A particularly interesting class of reactions which may be initiated by electron transfer are those which are catalytic with respect to electrons, so-called electron chain transfer catalysis (ETC). | | | Electron Transfer Chain Catalyzed Substitution Reactions of Cp'Mo(CO) | | | The techniques used include cyclic voltammetry to measure formal potentials, controlled potential electrolysis to measure the number of electrons transferred, chronoamperometry, chronocoulometry, and digital simulation to investigate kinetics, and spectroelectrochemistry to monitor changes in the IR spectra of the complexes upon oxidation or reduction. |
|
http://www3.baylor.edu/~Stephen_Gipson
(844 words)
|
|
| |
| | 18145012 |
| | AB - The oxidation of cytochrome f by the soluble cupredoxin plastocyanin is a central reaction in the photosynthetic electron transfer chain of all oxygenic organisms. | | | AB - The aa(3)-type cytochrome c oxidase of Rhodohacter sphaeroides, a proteobacterium of the alpha subgroup, is structurally similar to the core subunits of the terminal oxidase in the mitochondrial electron transport chain. | | | All these results suggest that chronic O-3 treatment induces a generalised decrease in the activity of electron transport chain components and in the photosystem protein and pigment content, which could be interpreted as an adaptation of the poplar plants to the adverse environmental conditions. |
|
http://www-u.life.uiuc.edu/labs/crofts/arc-lit/200112/18145012
(844 words)
|
|
| |
| | P450lect.html |
| | This handoff of electrons between proteins is called an electron transfer chain, and it is similar to the electron transfers that go on in complexes I to IV of the electron transfer chain in mitochondria. | | | The electrons are donated by another protein that binds briefly to the P450 and passes an electron from a prosthetic group. | | | NADPH is the source of electrons that flow from ferredoxin reductase to ferredoxin and then to P450. |
|
http://drnelson.utmem.edu/P450lect.html
(4610 words)
|
|
| |
| | * Dr Wilden - Specialist for Inner Ear Disease |
| | This assumed randomness of collisions is linked with the observation, however, that there is no need to postulate a structurally ordered chain of electron-transfer proteins in the lipid bilayer, and that the ordered transfer of electrons is due entirely to the specivity of the functional interactions among the components of the respiratory chain /3/. | | | Regarding the prevailing classical particle idea of electrons, the energy-transfer from nutritive molecules such as pyruvate to the molecular mitochondrial structures of the respiratory chain is described as a flow of high-energy electrons. | | | On the other hand, the absorption bands of the components of the mitochondrial respiratory chain (particularly the electron carriers with their antenna pigments) are in a comparable energy range (see Figure 1 and Table 2). |
|
http://www.dr-wilden.de/ehtmls/puben2.html
(4610 words)
|
|
| |
| | Enzymes |
| | Oxygen is the final receptor of the electrons in the electron transfer chain. | | | Flavin mononucleotide is the first molecule in a group of molecular complexes that form the electron transfer chain. | | | We need oxygen because it is the final receptor of electrons in the electron transfer chain in mitochondria. |
|
http://alpha1.fmarion.edu/~humanphys/enzymes.html
(769 words)
|
|
| |
| | Plant respiratory NAD(P)H dehydrogenases |
| | The first step of the electron transfer chain in animal mitochondria, the oxidation of NADH, is carried out by the proton-pumping complex I. Plant mitochondria differ by having additional non-proton-pumping NAD(P)H dehydrogenases in the electron transfer chain. | | | The NADH is oxidised and the electrons transferred to oxygen by the respiratory chain in the inner mitochondrial membrane (depicted in the image below). | | | Electron transfer through these enzymes will not be coupled to ATP synthesis and the efficiency of the respiratory process will be lower. |
|
http://www.biol.lu.se/cellorgbiol/dehydrogenase/proj_descr.html
(440 words)
|
|
| |
| | Biochemistry - Study Questions on Oxidative Phosphorylation |
| | R.capsulatus is a purple photosynthetic bacterium that synthesizes ATP using light as an energy source; it is also is capable of oxidative metabolism in the dark, using an electron transfer chain very similar to that of animal mitochondria. | | | Which component is most likely to oxidize reduced flavoproteins feeding into this electron transfer chain at the level of its quinone component. | | | A researcher recently submitted a manuscript reporting data that showed a bacterial electron transfer chain whose NADH dehydrogenase contained several proteins with iron-sulfur centers, and no other oxidation-reduction components. |
|
http://www.umsl.edu/~starling/biochem/study/sq-21.htm
(329 words)
|
|
| |
| | pdb22_5.html |
| | The residue numbers for the electron transfer chain are 1011-1013 and 1021-1023 for the chlorophylls, 2001-2002 for the phylloquinones, and 3001-3003 for the iron sulfur clusters. | | | You can look at the many photosystem I cofactors of the electron transfer chain and the antenna in PDB entry 1jb0. | | | This picture shows the electron transfer chain at the center, drawn in spacefilling spheres. |
|
http://www.scripps.edu/mb/goodsell/pdb/pdb22/pdb22_5.html
(185 words)
|
|
| |
| | Lecture 11. The proton circuit: coupling through the proton gradient |
| | The residual electron transfer is determined by the rate at which protons leak back across the membrane through non-specific pathways, or the rate at which the various proton pumps slip the "clutches" which couple their mechanisms to the gradient. | | | In the absence of reactions to use the proton gradient, the rate of electron transfer is slower by a factor of ~10 than in the presence of ADP + phosphate, or an uncoupler (the RC ratio is usually ~10, though the value depends on substrate). | | | Mitchell suggested that electron transport chains could act as proton pumps if they contained alternate electron carrying and H-carrying spans of redox couples arranged so as to transport electrons and hydrogen vectorially across the membrane. |
|
http://www.life.uiuc.edu/crofts/bioph354/lect11.html
(1591 words)
|
|
| |
| | Chapter14notesSP05.doc |
| | Model of electron flow is called the Z scheme Electron Transfer There are 4 distinct stages in electron transfer: Photosystem II splits water and transfers its electrons to plastiquinone. | | | Electrons are transferred from ferredoxin to NADP+ by NADP+ reductase Photons of light only involved in absorption of light in PS I and PS II --> provides energy to drive transfer of electrons to NADP+. | | | Electrons from P680 eventually replaced by splitting of a molecule of water: 2H2O ---> O2 + 4 H+ + 4 e- Electrons are first held by Mn atom, then transferred to Z, then P680* H2O ----> Mn ---> Z ---> P680* Cytochrome b6f transfers e- from plastiquinone to plasticyanin. |
|
http://www2.una.edu/aoyen/CellBiology/LectureNotes/Chapter14notesSP05.doc
(1350 words)
|
|
| |
| | Mitochondria |
| | Some ATP is generated directly during the Kreb's cycle, but most of the ATP produced in tissue respiration is generated by the electron transfer chain which takes place across the membranes of the mitochondrion. | | | This is the starting point of the electron transfer chain (also called Hydrogen transfer). | | | The energy in NADPH is used to generate ATP energy in the inner membranes of mitochondria in a process called the Hydrogen Transfer Chain. |
|
http://www.purchon.com/biology/mitochondria.htm
(639 words)
|
|
| |
| | Mitochondrion |
| | The electron transfer chain, also called the electron transport chain, is a sequence of complexes found in the mitochondrial membrane that accept electrons from electron... | | | Canute the Saint of Denmark Jay Miner Henry Kahnweiler Dziga Vertov Rutland (CDP), Massachusetts NATURA 2000 Allegra Coleman Wallingford, Connecticut Electron transfer chain From ezResult.com, the open information source. | | | An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phospha... |
|
http://www.essentialresults.com/related/Mitochondrion
(639 words)
|
|
| |
| | qcycle.html |
| | In the model, the enzymes of the photosynthetic electron transfer chain of Rhodobacter sphaeroides are shown as present in a stoichiometry of 2 reaction centers, 1 cytochrome c | | | The second electron in the b-cytochrome chain reduces the semiquinone with uptake of H | | | This completes the re-reduction of the high potential chain, and passes a second electron into the b-cytochrome chain. |
|
http://www.life.uiuc.edu/crofts/ahab/qcycle.html
(686 words)
|
|
| |
| | Chapter 10: |
| | electron is passed from the photosystem II primary acceptor to P700 of photosystem I via an electron transport chain | | | electrons are passed to the electron transport chain | | | each photosystem is composed of (a) antenna complex-absorb photons of light and pass the energy from one molecule to the next molecule, (b) reaction-center chlorophyll -chl a molecule that transfers an excited electron to start the light reactions, (c) primary electron acceptor-accepts the electron from the reaction-center chl |
|
http://ocean.st.usm.edu/~jrega/photosyn.htm
(686 words)
|
|
| |
| | Chemistry Department, Marquette University |
| | There is an alternative mode of activation that derives via one-electron oxidation of the organic substrate and this catalytic process has been termed as electron-transfer chain catalysis (ETC) by Chanon and hole catalysis by Bauld. | | | Catalysis by proton transfer differs from the electron transfer catalysis in that the reactive intermediates are diamagnetic cations as opposed to paramagnetic cation radicals. | | | In a mechanistic context, proton-transfer to an organic substrate (D) is tantamount to a two electron oxidation of D, and catalytic activation generally derives from the enhanced electrophilic reactivity of the cationic intermediates. |
|
http://www.marquette.edu/chem/personnel/groups/rathore/res_synthetic.html
(286 words)
|
|
| |
| | Chemiosmotic hypothesis - Wikipedia, the free encyclopedia |
| | The problem with the older paradigm is that no high energy intermediate was ever found, and the evidence for proton pumping by the complexes of the electron transfer chain grew too great to be ignored. | | | see also: mitochondrion, chloroplasts, chemiosmotic potential, electron transfer chain, cytochrome | | | The prevailing view was that the energy of electron transfer was stored as a stable high potential intermediate, a chemically more conservative concept. |
|
http://en.wikipedia.org/wiki/Chemiosmotic_hypothesis
(197 words)
|
|
| |
| | Contenido Home |
| | The respiratory chain is constituted by electron transfer molecules, which can undergo oxidation-reduction before the reducing equivalents are finally transferred toe oxygen. | | | The respiratory chain is constituted by a serie of electron carriers which are able to undergo reversible changes in their redox status. | | | The designation respiratory chain properly describes a series of enzymes and electron carriers catalyzing a sequence of reactions that produce oxygen consumption (respiration). |
|
http://www.antioxidantes.com.ar/12/Art083.htm
(197 words)
|
|
| |
| | FEBS Abstract |
| | These data demonstrate the existence of alternative redox reactions of the mitochondrial electron transfer chain, which evolved to generate pro-apoptotic ROS in response to specific stress-signals. | | | For this function, p66Shc utilizes reducing equivalents of the mitochondrial electron transfer chain through the oxidation of cytochrome c. | | | Electron transfer between cytochrome C and P66SHC generates reactive oxygen species that trigger mitochondrial apoptosis |
|
http://www.blackwellpublishing.com/febsabstracts2005/abstract.asp?id=41123
(206 words)
|
|
| |
| | Dr. Angerhofer's Page |
| | These studies help to determine the electronic structure of the components of the electron transfer chain in photosynthetic reaction centers and aid in the elucidation of the electron transfer mechanism which is responsible for the near unity quantum yield that these proteins exhibit. | | | The Angerhofer research group is working on the elucidation of energy and electron transfer mechanisms in natural and artificial photosynthetic systems. | | | It consists of a nonamer of subunits where each subunit is composed of an alpha- and a beta-amino acid chain as well as three bacteriochlorophyll a molecules (shown in yellow and green) and two carotenoid molecules (shown in red). |
|
http://www.chem.ufl.edu/angerhof.html
(284 words)
|
|
| |
| | COENZYME Q (UBIQUINONE, UBIQUINOL AND SEMIQUINONE) |
| | The oxidative unit consists mostly of a series of protein complexes in the inner mitochondrial membrane known as the respiratory chain or as the electron transfer chain. | | | CoQ is the only component of the electron transport chain that is lipid rather than protein, and CoQ is the only component that is not anchored to the inner mitochondrial membrane. | | | So the passing of hydrogen atoms along the respiratory chain is equivalent to the passing of electrons. |
|
http://www.benbest.com/nutrceut/CoEnzymeQ.html
(1527 words)
|
|
|
A cook's best friend