query: where are the molecules of the electron transport chain found in plant cell

pos: Electron transport chain aerobic respiration is molecular oxygen although a variety of acceptors other than oxygen such as sulfate exist in anaerobic respiration. Electron transport chains are used for extracting energy via redox reactions from sunlight in photosynthesis or, such as in the case of the oxidation of sugars, cellular respiration. In eukaryotes, an important electron transport chain is found in the inner mitochondrial membrane where it serves as the site of oxidative phosphorylation through the action of ATP synthase. It is also found in the thylakoid membrane of the chloroplast in photosynthetic eukaryotes. In bacteria, the electron transport chain is located in

pos: Active transport the cell potential. The sodium-potassium pump maintains the membrane potential by moving three Na+ ions out of the cell for every two K+ ions moved into the cell. Other sources of energy for Primary active transport are redox energy and photon energy (light). An example of primary active transport using Redox energy is the mitochondrial electron transport chain that uses the reduction energy of NADH to move protons across the inner mitochondrial membrane against their concentration gradient. An example of primary active transport using light energy are the proteins involved in photosynthesis that use the energy of photons to create

pos: Mitochondrial ROS 8-hydroxyguanine, formamidopyrimidine and 5-hydroxyuracil is base excision repair (BER).. BER occurs in both the cell nucleus and in mitochondria. Mitochondrial ROS Mitochondrial ROS (mtROS or mROS) are reactive oxygen species (ROS) that are produced by mitochondria. Generation of mitochondrial ROS mainly takes place at the electron transport chain located on the inner mitochondrial membrane during the process of oxidative phosphorylation (OXPHOS). Leakage of electrons at complex I and complex III from electron transport chains leads to partial reduction of oxygen to form superoxide. Subsequently, superoxide is quickly dismutated to hydrogen peroxide by two dismutases including superoxide dismutase 2 (SOD2) in

pos: Chemiosmosis from the cytoplasm. This "costs" one "extra" proton import per ATP, hence the actual efficiency is only 65% (= 2.4/3.67). The complete breakdown of glucose in the presence of oxygen is called cellular respiration. The last steps of this process occur in mitochondria. The reduced molecules NADH and FADH are generated by the Krebs cycle, glycolysis, and pyruvate processing. These molecules pass electrons to an electron transport chain, which uses the energy released to create a proton gradient across the inner mitochondrial membrane. ATP synthase then uses the energy stored in this gradient to make ATP. This process is called

pos: Beta oxidation Beta oxidation In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH, which are co-enzymes used in the electron transport chain. It is named as such because the beta carbon of the fatty acid undergoes oxidation to a carbonyl group. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty acids are oxidized in peroxisomes. The

pos: Beta oxidation disease as inborn errors of metabolism. Beta oxidation In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH, which are co-enzymes used in the electron transport chain. It is named as such because the beta carbon of the fatty acid undergoes oxidation to a carbonyl group. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty

neg: Viologen 2,4'-bipyridylium are highly toxic because these bipyridyl molecules readily form stable free radicals. The delocalization of charge, which allows for the molecule to stay as a free radical and these structures can be easily stabilized because the nitrogens can be readily hydrogenated. When in the body, these viologens interfere with electron transport chain, often causing cell death. These molecules act as redox cycling agents and are able to transfer their electron to molecular oxygen. Once the electron has been transferred to the molecular oxygen, it forms a superoxide radical that causes disproportionation, simultaneous reduction and oxidation. These reactive free radicals

neg: Electron transport chain Electron transport chain An electron transport chain (ETC) is a series of complexes that transfer electrons from electron donors to electron acceptors via redox (both reduction and oxidation occurring simultaneously) reactions, and couples this electron transfer with the transfer of protons (H ions) across a membrane. This creates an electrochemical proton gradient that drives the synthesis of adenosine triphosphate (ATP), a molecule that stores energy chemically in the form of highly strained bonds. The molecules of the chain include peptides, enzymes (which are proteins or protein complexes), and others. The final acceptor of electrons in the electron transport chain during

neg: Carbohydrate catabolism and the Krebs cycle. While the ATP count is glycolysis and the Krebs cycle is two ATP molecules, the electron transport chain contributes, at most, twenty-eight ATP molecules. A contributing factor is due to the energy potentials of NADH and FADH. As they are brought from the initial process, glycolysis, to the electron transport chain, the energy stored in them are now utilized. A second contributing factor is that cristae, the inner membranes of mitochondria, increase the surface area and therefore the amount of proteins in the membrane that assist in the synthesis of ATP. Along the electron transport chain,

neg: Crista molecules of water (HO). By accepting the electrons, oxygen allows the electron transport chain to continue functioning. The electrons from each NADH molecule can form a total of 3 ATP's from ADPs and phosphate groups through the electron transport chain, while each FADH molecule can produce a total of 2 ATPs. As a result, 10 NADH molecules (from glycolysis and the Krebs cycle), along with 2 FADH molecules, can form a total of 34 ATPs during aerobic respiration (from a single electron transport chain). This means that combined with the Krebs Cycle and glycolysis, the efficiency for the electron transport

neg: Microbial fuel cell In the second chamber of the MFC is another solution and the positively charged cathode. It is the equivalent of the oxygen sink at the end of the electron transport chain, external to the biological cell. The solution is an oxidizing agent that picks up the electrons at the cathode. As with the electron chain in the yeast cell, this could be a variety of molecules such as oxygen, although a more convenient option is a solid oxidizing agent, which requires less volume. Connecting the two electrodes is a wire (or other electrically conductive path). Completing the circuit and connecting

neg: Metabolic pathway of the pathway in the given compartment of the cell. For instance, the citric acid cycle, electron transport chain, and oxidative phosphorylation all take place in the mitochondrial membrane. In contrast, glycolysis, pentose phosphate pathway, and fatty acid biosynthesis all occur in the cytosol of a cell. There are two types of metabolic pathways that are characterized by their ability to either synthesize molecules with the utilization of energy (anabolic pathway) or break down of complex molecules by releasing energy in the process (catabolic pathway). The two pathways complement each other in that the energy released from one is used

neg: Membrane transport protein special mechanism for the phosphorylation of sugars as they are transported into bacteria (PEP group translocation) The transmembrane electron transfer carriers in the membrane include two-electron carriers, such as the disulfide bond oxidoreductases (DsbB and DsbD in E. coli) as well as one-electron carriers such as NADPH oxidase. Often these redox proteins are not considered transport proteins. Each carrier protein, even within the same cell membrane, is specific to one type or family of molecules. For example, GLUT1 is a named carrier protein found in almost all animal cell membranes that transports glucose across the bilayer. Other specific carrier proteins

neg: Organic solar cell separation in the interface between an electron donor and acceptor blend within the device’s active layer. These charges then transport to the device’s electrodes where the charges flow outside the cell, perform work and then re-enter the device on the opposite side. The cell's efficiency is limited by several factors, especially non-geminate recombination. Hole mobility leads to faster conduction across the active layer. Organic photovoltaics are made of electron donor and electron acceptor materials rather than semiconductor p-n junctions. The molecules forming the electron donor region of organic PV cells, where exciton electron-hole pairs are generated, are generally conjugated polymers

neg: Mitochondrion of FADH) that are a source of electrons for the "electron transport chain", and a molecule of GTP (that is readily converted to an ATP). The redox energy from NADH and FADH is transferred to oxygen (O) in several steps via the electron transport chain. These energy-rich molecules are produced within the matrix via the citric acid cycle but are also produced in the cytoplasm by glycolysis. Reducing equivalents from the cytoplasm can be imported via the malate-aspartate shuttle system of antiporter proteins or feed into the electron transport chain using a glycerol phosphate shuttle. Protein complexes in the inner

neg: Electron transport chain Lithotrophs have been found growing in rock formations thousands of meters below the surface of Earth. Because of their volume of distribution, lithotrophs may actually outnumber organotrophs and phototrophs in our biosphere. The use of inorganic electron donors as an energy source is of particular interest in the study of evolution. This type of metabolism must logically have preceded the use of organic molecules as an energy source. Bacteria can use a number of different electron donors. When organic matter is the energy source, the donor may be NADH or succinate, in which case electrons enter the electron transport chain

neg: Endomembrane system have evolved from the latter (see below: Evolution). The nuclear membrane contains a lipid bilayer that encompass the contents of the nucleus. The endoplasmic reticulum (ER) is a synthesis and transport organelle that branches into the cytoplasm in plant and animal cells. The Golgi apparatus is a series of multiple compartments where molecules are packaged for delivery to other cell components or for secretion from the cell. Vacuoles, which are found in both plant and animal cells (though much bigger in plant cells), are responsible for maintaining the shape and structure of the cell as well as storing waste products.

neg: Electron transport chain and inorganic. If oxygen is available, it is invariably used as the terminal electron acceptor, because it generates the greatest Gibbs free energy change and produces the most energy. In anaerobic environments, different electron acceptors are used, including nitrate, nitrite, ferric iron, sulfate, carbon dioxide, and small organic molecules such as fumarate. Since electron transport chains are redox processes, they can be described as the sum of two redox pairs. For example, the mitochondrial electron transport chain can be described as the sum of the NAD/NADH redox pair and the O/HO redox pair. NADH is the electron donor and O

neg: Electron transport chain can synthesize different transmembrane complexes and produce different electron transport chains in their cell membranes. Bacteria select their electron transport chains from a DNA library containing multiple possible dehydrogenases, terminal oxidases and terminal reductases. The situation is often summarized by saying that electron transport chains in bacteria are "branched", "modular", and "inducible". In oxidative phosphorylation, electrons are transferred from a low-energy electron donor (e.g., NADH) to an acceptor (e.g., O) through an electron transport chain. In photophosphorylation, the energy of sunlight is used to "create" a high-energy electron donor and an electron acceptor. Electrons are then transferred from the donor

neg: Light-dependent reactions (hydrogen, hydrogen sulfide, sulfur, sulfite, or organic molecules such as succinate and lactate) to feed electrons into a reverse electron transport chain. Green sulfur bacteria contain a photosystem that is analogous to PS I in chloroplasts: There are two pathways of electron transfer. In "cyclic electron transfer", electrons are removed from an excited chlorophyll molecule, passed through an electron transport chain to a proton pump, and then returned to the chlorophyll. The mobile electron carriers are, as usual, a lipid-soluble quinone and a water-soluble cytochrome. The resulting proton gradient is used to make ATP. In "noncyclic electron transfer", electrons are

neg: Barth syndrome associated with Barth syndrome. The tafazzin gene product functions as an acyltransferase in complex lipid metabolism. In 2008, Dr. Kulik found that all the BTHS individuals that he tested had abnormalities in their cardiolipin molecules, a lipid found inside the mitochondria of cells. Cardiolipin is intimately connected with the electron transport chain proteins and the membrane structure of the mitochondria which is the energy producing organelle of the cell. The human tafazzin gene, NG_009634, is listed as over 10,000 base pairs in length and the full-length mRNA, NM_000116, is 1919 nucleotides long encoding 11 exons with a predicted protein length

neg: Antimycin A subsequently inhibited, as protons are unable to flow through the ATP synthase complex in the absence of a proton gradient. This inhibition also results in the formation of the toxic free radical superoxide. The rate of superoxide production exceeds the cellular mechanisms to scavenge it, overwhelming the cell and leading to cell death. It has also been found to inhibit the cyclic electron flow within photosynthetic systems along the proposed ferredoxin quinone reductase pathway. Although cyanide acts to block the electron transport chain, Antimycin A and cyanide act in different mechanisms. Cyanide binds a site in neighboring protein where iron

neg: Cyanide dissolved in aqueous sodium hydroxide solution to produce sodium cyanide. Many cyanides are highly toxic. The cyanide anion is an inhibitor of the enzyme cytochrome c oxidase (also known as aa) in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It attaches to the iron within this protein. The binding of cyanide to this enzyme prevents transport of electrons from cytochrome c to oxygen. As a result, the electron transport chain is disrupted, meaning that the cell can no longer aerobically produce ATP for energy. Tissues that depend highly on

neg: Electron transport chain to two molecules of cytochrome "c", a water-soluble electron carrier located within the intermembrane space. The two other electrons sequentially pass across the protein to the Q site where the quinone part of ubiquinone is reduced to quinol. A proton gradient is formed by one quinol (<chem>2H+2e-</chem>) oxidations at the Q site to form one quinone (<chem>2H+2e-</chem>) at the Q site. (in total four protons are translocated: two protons reduce quinone to quinol and two protons are released from two ubiquinol molecules). When electron transfer is reduced (by a high membrane potential or respiratory inhibitors such as antimycin A), Complex

neg: Electron transport chain their cell membrane. In chloroplasts, light drives the conversion of water to oxygen and NADP to NADPH with transfer of H ions across chloroplast membranes. In mitochondria, it is the conversion of oxygen to water, NADH to NAD and succinate to fumarate that are required to generate the proton gradient. Electron transport chains are major sites of premature electron leakage to oxygen, generating superoxide and potentially resulting in increased oxidative stress. The electron transport chain consists of a spatially separated series of redox reactions in which electrons are transferred from a donor molecule to an acceptor molecule. The underlying force

neg: Cytochrome c oxidase in animal brain. Cytochrome c oxidase The enzyme cytochrome c oxidase or Complex IV, is a large transmembrane protein complex found in bacteria, archaea, and in eukaryotes in their mitochondria. It is the last enzyme in the respiratory electron transport chain of cells located in the membrane. It receives an electron from each of four cytochrome c molecules, and transfers them to one dioxygen molecule, converting the molecular oxygen to two molecules of water. In this process it binds four protons from the inner aqueous phase to make two water molecules, and translocates another four protons across the membrane, increasing

neg: Cytochrome c oxidase Cytochrome c oxidase The enzyme cytochrome c oxidase or Complex IV, is a large transmembrane protein complex found in bacteria, archaea, and in eukaryotes in their mitochondria. It is the last enzyme in the respiratory electron transport chain of cells located in the membrane. It receives an electron from each of four cytochrome c molecules, and transfers them to one dioxygen molecule, converting the molecular oxygen to two molecules of water. In this process it binds four protons from the inner aqueous phase to make two water molecules, and translocates another four protons across the membrane, increasing the transmembrane difference

neg: Light-dependent reactions transfers the electron from PSII to the proton pump, cytochrome b6f. The ultimate electron donor of PSII is water. Cytochrome b6f proceeds the electron chain to PSI through plastocyanin molecules. PSI is able to continue the electron transfer in two different ways. It can transfer the electrons either to plastoquinol again, creating a cyclic electron flow, or to an enzyme called FNR (Ferredoxin—NADP(+) reductase), creating a non-cyclic electron flow. PSI releases FNR into the stroma, where it reduces to NADPH. Activities of the electron transport chain, especially from cytochrome b6f, lead to pumping of protons from the stroma to the

neg: Chlorophyll a electron transport chain. These two systems are different in their redox potentials for one-electron oxidation. The E for P700 is approximately 500mV, while the E for P680 is approximately 1,100-1,200 mV. Chlorophyll "a" is very important in the energy phase of photosynthesis. Two electrons need to be passed to an electron acceptor for the process of photosynthesis to proceed. Within the reaction centers of both photosystems there are a pair of chlorophyll "a" molecules that pass electrons on to the transport chain through redox reactions. Chlorophyll a Chlorophyll "a" is a specific form of chlorophyll used in oxygenic photosynthesis. It

neg: Cytochrome b Cytochrome b Cytochrome b is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In the mitochondrion of eukaryotes and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiquinol-cytochrome c reductase. In plant chloroplasts and cyanobacteria, there is an analogous protein, cytochrome b6, a component of the plastoquinone-plastocyanin reductase (), also known as the b6f complex. These complexes are involved in electron transport, the pumping

neg: Cardiolipin to have a lamellar-to-hexagonal (L-H) phase transition. And it is believed to have a close connection with membrane fusion. The enzyme cytochrome c oxidase or Complex IV is a large transmembrane protein complex found in bacteria and the mitochondrion. It is the last enzyme in the respiratory electron transport chain of mitochondria (or bacteria) located in the mitochondrial (or bacterial) membrane. It receives an electron from each of four cytochrome c molecules, and transfers them to one oxygen molecule, converting molecular oxygen to two molecules of water. Complex IV has been shown to require two associated CL molecules in order

neg: Cytoplasmic streaming in the oocyte cell. Cytoplasmic streaming Cytoplasmic streaming, also called protoplasmic streaming and cyclosis, is where there is flow inside the cytoplasm. It is typically observed in large plant and animal cells. Here flow means that the cytoplasm is moving inside the cell, it is not stationary. The flow is driven by forces from the cytoskeleton, and it is likely that the function of flow is at least partly to speed up transport of molecules and organelles around the cell. Cytoplasmic streaming is usually found in unusually large cells, greater than approximately 0.1 mm. In smaller cells, diffusion of molecules

neg: Electron transport chain many as three proton pumps, like mitochondria, or they may contain only one or two. They always contain at least one proton pump. In the present day biosphere, the most common electron donors are organic molecules. Organisms that use organic molecules as an electron source are called "organotrophs". Organotrophs (animals, fungi, protists) and "phototrophs" (plants and algae) constitute the vast majority of all familiar life forms. Some prokaryotes can use inorganic matter as an energy source. Such an organism is called a "lithotroph" ("rock-eater"). Inorganic electron donors include hydrogen, carbon monoxide, ammonia, nitrite, sulfur, sulfide, manganese oxide, and ferrous iron.

neg: Carbohydrate catabolism Carbohydrate catabolism Digestion is the breakdown of carbohydrates to yield an energy rich compound called ATP. The production of ATP is achieved through the oxidation of glucose molecules. In oxidation, the electrons are stripped from a glucose molecule to reduce NAD+ and FAD. NAD+ and FAD possess a high energy potential to drive the production of ATP in the electron transport chain. ATP production occurs in the mitochondria of the cell. There are two methods of producing ATP: aerobic and anaerobic. In aerobic respiration, oxygen is required. Oxygen plays a key role as it increases ATP production from 4 ATP

neg: Metabolism deamination of glutamate forms α-ketoglutarate. The glucogenic amino acids can also be converted into glucose, through gluconeogenesis (discussed below). In oxidative phosphorylation, the electrons removed from organic molecules in areas such as the protagon acid cycle are transferred to oxygen and the energy released is used to make ATP. This is done in eukaryotes by a series of proteins in the membranes of mitochondria called the electron transport chain. In prokaryotes, these proteins are found in the cell's inner membrane. These proteins use the energy released from passing electrons from reduced molecules like NADH onto oxygen to pump protons across

neg: Contorted aromatics due to resonance of electrons and hinder the possibility of electron hole pair recombination for having suitable HOMO and LUMO offsets at donor and acceptor interphase while allowing the antagonistic charge percolation pathways. These contorted molecules show remarkable phenomenon of self- assembly. Based upon the data collected from OFET and OPVs, these molecules show efficient charge transport. The c-HBC, c-OCBC and c-DBTTC act as electron donors and c-PDIs as electron acceptors. The contorted non-planar structure allows these molecules to express sufficient charge transport in self-assembled layers. The self-assembly characteristics change in case of alkyl chain derivatives of c-HBC into orthorhombic

neg: Polar auxin transport Polar auxin transport Polar auxin transport is the regulated transport of the plant hormone auxin in plants. It is an active process, the hormone is transported in cell-to-cell manner and one of the main features of the transport is its directionality (polarity). The polar auxin transport has coordinative function in plant development, the following spatial auxin distribution underpins most of plant growth responses to its environment and plant growth and developmental changes in general. Polar auxin transport (PAT) is directional and active flow of auxin molecules through the plant tissues. The flow of auxin molecules through the neighboring cells is

neg: Electron transport chain structures imbedded in the membrane. The mobile cytochrome electron carrier in mitochondria is cytochrome "c". Bacteria use a number of different mobile cytochrome electron carriers. Other cytochromes are found within macromolecules such as "Complex III" and "Complex IV". They also function as electron carriers, but in a very different, intramolecular, solid-state environment. Electrons may enter an electron transport chain at the level of a mobile cytochrome or quinone carrier. For example, electrons from inorganic electron donors (nitrite, ferrous iron, etc.) enter the electron transport chain at the cytochrome level. When electrons enter at a redox level greater than NADH, the

neg: Electrochemical gradient animal cell has a transmembrane electrical potential of -50 mV to -70 mV inside the cell relative to the outside. Electrochemical gradients also play a role in establishing proton gradients in oxidative phosphorylation in mitochondria. The final step of cellular respiration is the electron transport chain. Four complexes embedded in the inner membrane of the mitochondrion make up the electron transport chain. However, only complexes I, III, and IV pump protons from the matrix to the intermembrane space (IMS). In total, there are ten protons translocated from the matrix to the IMS which generates an electrochemical potential of more than

neg: Cytoplasmic streaming Cytoplasmic streaming Cytoplasmic streaming, also called protoplasmic streaming and cyclosis, is where there is flow inside the cytoplasm. It is typically observed in large plant and animal cells. Here flow means that the cytoplasm is moving inside the cell, it is not stationary. The flow is driven by forces from the cytoskeleton, and it is likely that the function of flow is at least partly to speed up transport of molecules and organelles around the cell. Cytoplasmic streaming is usually found in unusually large cells, greater than approximately 0.1 mm. In smaller cells, diffusion of molecules will be rapid but

neg: Mitochondrial matrix forward. The production of ATP also serves as a means of regulation by acting as an inhibitor for Isocitrate dehydrogenase, Pyruvate dehydrogenase, the electron transport chain protein complexes, and ATP syntahase. While ADP acts as an activator. The mitochondria contains its own set of DNA used to produce proteins found in the electron transport chain. The mitochondrial DNA only codes for about thirteen proteins that are used in processing mitochondrial transcripts, ribosomal proteins, ribosomal RNA, transfer RNA, and protein subunits found in the protein complexes of the electron transport chain. Mitochondrial matrix In the mitochondrion, the matrix is the space

neg: Cellular respiration efficiency of the whole process and the likely maximum is closer to 28–30 ATP molecules. In practice the efficiency may be even lower because the inner membrane of the mitochondria is slightly leaky to protons. Other factors may also dissipate the proton gradient creating an apparently leaky mitochondria. An uncoupling protein known as thermogenin is expressed in some cell types and is a channel that can transport protons. When this protein is active in the inner membrane it short circuits the coupling between the electron transport chain and ATP synthesis. The potential energy from the proton gradient is not used

neg: Electron transport chain proton gradient). ATP synthase is also readily reversible. Thus ATP can be used to build a proton gradient, which in turn can be used to make NADH. This process of "reverse electron transport" is important in many prokaryotic electron transport chains. In eukaryotes, NADH is the most important electron donor. The associated electron transport chain is NADH → "Complex I" → Q → "Complex III" → cytochrome "c" → "Complex IV" → O where "Complexes I, III" and" IV" are proton pumps, while Q and cytochrome "c" are mobile electron carriers. The electron acceptor is molecular oxygen. In prokaryotes (bacteria

neg: Photoinduced electron transfer an orbital that is higher in energy than where it previously resided. This is often described as a charge separated electron-hole pair when working with semiconductors. In the absence of a proper electron donor or acceptor it is possible for such molecules to undergo ordinary fluorescence emission. The electron transfer is one form of photoquenching. In many photo-productive systems this charge separation is kinetically isolated by delivery of the electron to a lower energy conductor attached to the p/n junction or into an electron transport chain. In this case some of the energy can be captured to do work. If

neg: Chloroplast depleted electrons at the end of an electron transport chain. Normally, the reenergized electrons are taken by NADP, though sometimes they can flow back down more H-pumping electron transport chains to transport more hydrogen ions into the thylakoid space to generate more ATP. This is termed cyclic photophosphorylation because the electrons are recycled. Cyclic photophosphorylation is common in plants, which need more ATP than NADPH. The Calvin cycle, also known as the dark reactions, is a series of biochemical reactions that fixes CO into G3P sugar molecules and uses the energy and electrons from the ATP and NADPH made in

neg: Exocytosis Exocytosis Exocytosis () is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell ("exo-" + "cytosis") by expelling them through an energy-dependent process. Exocytosis and its counterpart, endocytosis, are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. It is a process of which the contents of a vacuole are released, since the plant cell has large amounts of content in its vacuole, when Exocytosis is in

neg: Plant lipid transfer proteins Plant lipid transfer proteins Plant lipid transfer proteins, also known as plant LTPs or PLTPs, are a group of highly-conserved proteins of about 7-9kDa found in higher plant tissues. As its name implies, lipid transfer proteins are responsible for the shuttling of phospholipids and other fatty acid groups between cell membranes. LTPs are divided into two structurallyrelated subfamilies according to their molecular masses: LTP1s (9 kDa) and LTP2s (7 kDa). Various LTPs bind a wide range of ligands, including fatty acids (FAs) with a C–C chain length, acyl derivatives of coenzyme A (CoA), phospho- and galactolipids, prostaglandin B, sterols, molecules

neg: Mitochondrial permeability transition pore activate harmful calcium-dependent proteases such as calpain. Reactive oxygen species (ROS) are also produced as a result of opening the MPT pore. MPT can allow antioxidant molecules such as glutathione to exit mitochondria, reducing the organelles' ability to neutralize ROS. In addition, the electron transport chain (ETC) may produce more free radicals due to loss of components of the ETC, such as cytochrome "c", through the MPTP. Loss of ETC components can lead to escape of electrons from the chain, which can then reduce molecules and form free radicals. MPT causes mitochondria to become permeable to molecules smaller than 1.5

neg: Gaseous signaling molecules be produced by any of four routes: (i) L-arginine-dependent nitric oxide synthase, (although the existence of animal NOS homologs in plants is debated), (ii) plasma membrane-bound nitrate reductase, (iii) mitochondrial electron transport chain, or (iv) non-enzymatic reactions. It is a signaling molecule, acts mainly against oxidative stress and also plays a role in plant pathogen interactions. Treating cut flowers and other plants with nitric oxide has been shown to lengthen the time before wilting. Two important biological reaction mechanisms of nitric oxide are S-nitrosation of thiols, and nitrosylation of transition metal ions. S-nitrosation involves the (reversible) conversion of thiol groups,

neg: Microbial fuel cell alumina, mullite, pyrophyllite and terracotta. When microorganisms consume a substance such as sugar in aerobic conditions, they produce carbon dioxide and water. However, when oxygen is not present, they produce carbon dioxide, protons/hydrogen ions and electrons, as described below: Microbial fuel cells use inorganic mediators to tap into the electron transport chain of cells and channel electrons produced. The mediator crosses the outer cell lipid membranes and bacterial outer membrane; then, it begins to liberate electrons from the electron transport chain that normally would be taken up by oxygen or other intermediates. The now-reduced mediator exits the cell laden with

neg: Organic solar cell functions in organic molecules are more localized, and electrostatic attraction can thus keep the electron and hole together as an exciton. The electron and hole can be dissociated by providing an interface across which the chemical potential of electrons decreases. The material that absorbs the photon is the donor, and the material acquiring the electron is called the acceptor. In Fig. 2, the polymer chain is the donor and the fullerene is the acceptor. Even after dissociation, the electron and hole may still be joined as a "geminate pair", and an electric field is then required to separate them. The

neg: Exoelectrogen While these proteins are diverse (taking on both membrane-bound or soluble forms), their common locations in the outer membrane or periplasm in Gram-negative and Gram-positive bacteria provide intimate contact for electron transfer. Additionally, the presence of electron shuttling molecules dramatically increases the direct transfer rate by up to 80%. As an example, in "Shewanella oneidensis MR-1", transport is characterized through a series of redox and structural proteins extending from the cytoplasmic membrane to the outer cell surface (similar to Figure 1). Flavins are secreted which are thought to bridge the “gap” between cell surface protein(s) and the external metal, which

neg: MTORC1 yeast increases cellular respiration in the mitochondria by enhancing the translation of mitochondrial DNA that encodes for the complexes involved in the electron transport chain. When this electron transport chain is not as efficient, the unreduced oxygen molecules in the mitochondrial cortex may accumulate and begin to produce reactive oxygen species. It is important to note that both cancer cells as well as those cells with greater levels of mTORC1 both rely more on glycolysis in the cytosol for ATP production rather than through oxidative phosphorylation in the inner membrane of the mitochondria. Inhibition of mTORC1 has also been shown

neg: Oxidative phosphorylation the Q cycle, one molecule of QH were used to directly reduce two molecules of cytochrome c, the efficiency would be halved, with only one proton transferred per cytochrome c reduced. Cytochrome c oxidase, also known as "complex IV", is the final protein complex in the electron transport chain. The mammalian enzyme has an extremely complicated structure and contains 13 subunits, two heme groups, as well as multiple metal ion cofactors – in all, three atoms of copper, one of magnesium and one of zinc. This enzyme mediates the final reaction in the electron transport chain and transfers electrons to

neg: Anoxygenic photosynthesis transport chain, proteins such as halorhodopsin capture light energy with the aid of diterpenes to move ions against the gradient and produce ATP via chemiosmosis in the manner of mitochondria. There are two main types of anaerobic photosynthetic electron transport chains in bacteria. The type I reaction centers found in GSB, Chloracidobacterium, and Heliobacteria and the type II reaction centers found in FAPs and Purple Bacteria Type I Reaction Centers The electron transport chain of green sulfur bacteria — such as is present in model organism "Chlorobaculum tepidum" — uses the reaction centre bacteriochlorophyll pair, P840. When light is absorbed

neg: Photosynthetic reaction centre pigment molecules, or passed to them by resonance transfer from a surrounding light-harvesting complex, they release two electrons into an electron transport chain. Light is made up of small bundles of energy called photons. If a photon with the right amount of energy hits an electron, it will raise the electron to a higher energy level. Electrons are most stable at their lowest energy level, what is also called its ground state. In this state, the electron is in the orbit that has the least amount of energy. Electrons in higher energy levels can return to ground state in a

neg: Botany of spatial scales. Subcellular transport of ions, electrons and molecules such as water and enzymes occurs across cell membranes. Minerals and water are transported from roots to other parts of the plant in the transpiration stream. Diffusion, osmosis, and active transport and mass flow are all different ways transport can occur. Examples of elements that plants need to transport are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. In vascular plants, these elements are extracted from the soil as soluble ions by the roots and transported throughout the plant in the xylem. Most of the elements required for plant nutrition come

neg: Deinococcus marmoris cycle and produces the molecules NADH and FADH for its electron transport chain and the eventual production of ATP. A byproduct of the production of ATP is O₂ which can be either endogenously or exogenously induced to create a reactive oxidative species (ROS). The induction of O₂ into a ROS is by gamma irradiation which can be reduced with an abundance of Mn(II) inside the cell as the reduced form of Mn(IV). Mn(II) is able to reduce the amount of ROS in "Deinococcus radiodurans" because it acts as an antioxidant and assists other enzymatic reactions that reduce the total amount

neg: MPTP MPPP contaminated with MPTP will develop these symptoms. MPTP itself is not toxic, and as a lipophilic compound can cross the blood–brain barrier. Once inside the brain, MPTP is metabolized into the toxic cation 1-methyl-4-phenylpyridinium (MPP+) by the enzyme monoamine oxidase B (MAO-B) of glial cells, specifically astrocytes. MPP+ kills primarily dopamine-producing neurons in a part of the brain called the pars compacta of the substantia nigra. MPP+ interferes with complex I of the electron transport chain, a component of mitochondrial metabolism, which leads to cell death and causes the buildup of free radicals, toxic molecules that contribute further to

neg: Dioxygen in biological reactions almost all oxygen produced in tropical forests is consumed by organisms living there. A simplified overall formula for photosynthesis is: Photolytic oxygen evolution during photosynthesis occurs via the light-dependent oxidation of water to molecular oxygen and can be written as the following simplified chemical reaction: 2HO → 4e + 4H + O The reaction occurs in the thylakoid membranes of cyanobacteria, and algal and plant chloroplasts and requires the energy of four photons. The electrons from the oxidized water molecules replace electrons in the P component of photosystem II, which have been removed into an electron transport chain via light-dependent

neg: Exoelectrogen phylogenetically diverse, thus some chelating agents may reduce iron outside the cell acting as electron shuttles, while others may deliver iron to the cell for membrane bound reduction. Exoelectrogen An exoelectrogen normally refers to a microorganism that has the ability to transfer electrons extracellularly. While exoelectrogen is the predominant name, other terms have been used: electrochemically active bacteria, anode respiring bacteria, and electricigens. Electrons exocytosed in this fashion are produced following ATP production using an electron transport chain (ETC) during oxidative phosphorylation. Conventional cellular respiration requires a final electron acceptor to receive these electrons. Cells that use molecular oxygen (O)

neg: Plant transformation vector transferred to the plant cell but remains within the bacterial cell. Plasmids replicate to produce many plasmid molecules in each host bacterial cell. The number of copies of each plasmid in a bacterial cell is determined by the replication origin. This is the position within the plasmids molecule where DNA replication is initiated. Most binary vectors have a higher number of plasmids copies when they replicate in "E. coli", the plasmid copy-number is usually less when the plasmid is resident within "Agrobacterium tumefaciens". Plasmids can also be replicated in the polymerase chain reaction (PCR). T-DNA contains two types of genes:

neg: Sieve tube element with companion cells, which are cells that combine with sieve tubes to create the sieve element-companion cell complex. This allows for supply and maintenance of the plant cells and for signaling between distant organs within the plant. Sieve tubes members do not have ribosomes or a nucleus and thus need companion cells to help them function as transport molecules. Companion cells provide Sieve tube members with proteins necessary for signaling and ATP in order to help them transfer molecules between different parts of the plant. It is the companion cells that helps transport carbohydrates from outside the cells into the

neg: Electron transport chain of protons across a membrane, producing a proton gradient. The proton gradient is used to produce useful work. About 30 work units are produced per electron transport. Electron transport chain An electron transport chain (ETC) is a series of complexes that transfer electrons from electron donors to electron acceptors via redox (both reduction and oxidation occurring simultaneously) reactions, and couples this electron transfer with the transfer of protons (H ions) across a membrane. This creates an electrochemical proton gradient that drives the synthesis of adenosine triphosphate (ATP), a molecule that stores energy chemically in the form of highly strained bonds.

neg: Active transport ATP-driven pumps. Usually, there are several domains involved in the overall transporter protein's structure, including two nucleotide-binding domains that constitute the ATP-binding motif and two hydrophobic transmembrane domains that create the "pore" component. In broad terms, ABC transporters are involved in the import or export of molecules across a cell membrane; yet within the protein family there is an extensive range of function. In plants, ABC transporters are often found within cell and organelle membranes, such as the mitochondria, chloroplast, and plasma membrane. There is evidence to support that plant ABC transporters play a direct role in pathogen response, phytohormone

neg: Electron transport chain to the acceptor through another electron transport chain. Photosynthetic electron transport chains have many similarities to the oxidative chains discussed above. They use mobile, lipid-soluble carriers (quinones) and mobile, water-soluble carriers (cytochromes, etc.). They also contain a proton pump. It is remarkable that the proton pump in "all" photosynthetic chains resembles mitochondrial "Complex III". Photosynthetic electron transport chains are discussed in greater detail in the articles Photophosphorylation, Photosynthesis, Photosynthetic reaction center and Light-dependent reaction. Electron transport chains are redox reactions that transfer electrons from an electron donor to an electron acceptor. The transfer of electrons is coupled to the translocation

neg: Salicylhydroxamic acid oxidase (AOX) enzyme in the mitochondrial electron transport chain system, salicylhdroxamic acid acts as an inhibitor of the enzyme, blocking the largely uninhibited flow of electrons through AOX. AOX acts as a "short circuit" of the normal electron chain, dissipating electrons with a much-decreased translocation of protons, and therefore diminished production of ATP by oxidative phosphorylation. When AOX is blocked by SHAM, electrons are forced through the cytochrome pathway and through complex IV, allowing observation of the operation of the cytochrome pathway without AOX activity. The AOX pathway is found to be the exclusive electron transport pathway in "Trypanosoma brucei",

neg: Cell wall resist the strain of physical forces. The primary cell wall of most plant cells is freely permeable to small molecules including small proteins, with size exclusion estimated to be 30-60 kDa. The pH is an important factor governing the transport of molecules through cell walls. Cell walls evolved independently in many groups, including within the photosynthetic eukaryotes. In these lineages, the cell wall is closely related to the evolution of multicellularity, terrestrialization and vascularization. The walls of plant cells must have sufficient tensile strength to withstand internal osmotic pressures of several times atmospheric pressure that result from the difference in

neg: Active transport in "Nicotiana tabacum" BY2 cells and is expressed in the presence of microbial elicitors. NtPDR1 is localized in the root epidermis and aerial trichomes of the plant. Experiments using antibodies specifically targeting NtPDR1 followed by Western blotting allowed for this determination of localization. Furthermore, it is likely that the protein NtPDR1 actively transports out antimicrobial diterpene molecules, which are toxic to the cell at high levels. In secondary active transport, also known as "coupled transport" or "cotransport", energy is used to transport molecules across a membrane; however, in contrast to primary active transport, there is no direct coupling of ATP;

neg: Geothrix fermentans that describes the ability of certain bacteria to utilize molecules containing metals such as iron, manganese, or others as electron acceptors in the electron transport chain to produce adenosine triphosphate (ATP). The bacterium "G. fermentans" performs a certain type of metal respiration called dissimilatory Fe(III) oxide (iron oxide) reduction. This organism as well as species from the families" Shewanella" and "Geobacteraceae", which includes genera such as "Geovibrio" and "Desulfuromonas" are commonly referred to in microbiology as "Dissimilatory Iron Reducing Bacteria" or "DIRB." Though these families and "G. fermentans" are phylogenetically separate and distinct, they may often be grouped together based

neg: Oxidative phosphorylation The amount of energy released by oxidative phosphorylation is high, compared with the amount produced by anaerobic fermentation. Glycolysis produces only 2 ATP molecules, but somewhere between 30 and 36 ATPs are produced by the oxidative phosphorylation of the 10 NADH and 2 succinate molecules made by converting one molecule of glucose to carbon dioxide and water, while each cycle of beta oxidation of a fatty acid yields about 14 ATPs. These ATP yields are theoretical maximum values; in practice, some protons leak across the membrane, lowering the yield of ATP. The electron transport chain carries both protons and electrons,

neg: Bioenergetic systems lactic acid system is used predominately for the "kick" at the end of a race. This stage of the aerobic system occurs on the cristae (infoldings on the membrane of the mitochondria). The NADH+ from glycolysis and the Krebs cycle, and the FADH+ from the Krebs cycle produce electron carriers at decreasing energy levels, in which energy is released to reform ATP. Each NADH+ that travels this electron transport chain provides enough energy for 3 molecules of ATP, and each molecule of FADH+ provides enough energy for 2 molecules of ATP. If you do your math this means that 10

neg: Cellular respiration However some anaerobic organisms, such as methanogens are able to continue with anaerobic respiration, yielding more ATP by using other inorganic molecules (not oxygen) as final electron acceptors in the electron transport chain. They share the initial pathway of glycolysis but aerobic metabolism continues with the Krebs cycle and oxidative phosphorylation. The post-glycolytic reactions take place in the mitochondria in eukaryotic cells, and in the cytoplasm in prokaryotic cells. 1. Glycolysis: --- "2 ATPs + Glucose → 2 Pyruvic Acid + 4 Hydrogen + 4 ATPs" 2. Formation of Acetyl CoA: --- "2 Pyruvic Acid + 2 CoA → 2

neg: Plant nutrition supply from the carbon dioxide in the air by the process of photosynthesis. Each of these nutrients is used in a different place for a different essential function. Carbon forms the backbone of most plant biomolecules, including proteins, starches and cellulose. Carbon is fixed through photosynthesis; this converts carbon dioxide from the air into carbohydrates which are used to store and transport energy within the plant. Hydrogen also is necessary for building sugars and building the plant. It is obtained almost entirely from water. Hydrogen ions are imperative for a proton gradient to help drive the electron transport chain in

neg: Electron transport chain III may leak electrons to molecular oxygen, resulting in superoxide formation. This complex is inhibited by British Antilewisite(BAL), Napthoquinone and Antimycin. In "Complex IV" (cytochrome "c" oxidase; ), sometimes called cytochrome AA3, four electrons are removed from four molecules of cytochrome "c" and transferred to molecular oxygen (O), producing two molecules of water. At the same time, eight protons are removed from the mitochondrial matrix (although only four are translocated across the membrane), contributing to the proton gradient. The activity of cytochrome c oxidase is inhibited by cyanide, carbon monoxide, azide, hydrogen sulphide(HS). According to the chemiosmotic coupling hypothesis, proposed

neg: Photoheterotroph they use a bacteriochlorophyll-based reaction center, or they use a bacteriorhodopsin. The chlorophyll-based mechanism is similar to that used in photosynthesis, where light excites the molecules in a reaction center and causes a flow of electrons through an electron transport chain (ETS). This flow of electrons through the proteins causes hydrogen ions to be pumped across a membrane. The energy stored in this proton gradient is used to drive ATP synthesis. Unlike in photoautotrophs, the electrons flow only in a cyclic pathway: electrons released from the reaction center flow through the ETS and return to the reaction center. They are

neg: Photosynthesis the electron is passed down the electron acceptor molecules and returns to photosystem I, from where it was emitted, hence the name "cyclic reaction". Linear electron transport through a photosystem will leave the reaction center of that photosystem oxidized. Elevating another electron will first require re-reduction of the reaction center. The excited electrons lost from the reaction center (P700) of photosystem I are replaced by transfer from plastocyanin, whose electrons come from electron transport through photosystem II. Photosystem II, as the first step of the "Z-scheme", requires an external source of electrons to reduce its oxidized chlorophyll "a" reaction center,

neg: Cellular respiration coenzymes are oxidized by the electron transport chain and used for oxidative phosphorylation. Although there is a theoretical yield of 38 ATP molecules per glucose during cellular respiration, such conditions are generally not realized because of losses such as the cost of moving pyruvate (from glycolysis), phosphate, and ADP (substrates for ATP synthesis) into the mitochondria. All are actively transported using carriers that utilize the stored energy in the proton electrochemical gradient. The outcome of these transport processes using the proton electrochemical gradient is that more than 3 H are needed to make 1 ATP. Obviously this reduces the theoretical

neg: Auxin plant is a key factor for plant growth, its reaction to its environment, and specifically for development of plant organs (such as leaves or flowers). It is achieved through very complex and well coordinated active transport of auxin molecules from cell to cell throughout the plant body — by the so-called polar auxin transport. Thus, a plant can (as a whole) react to external conditions and adjust to them, without requiring a nervous system. Auxins typically act in concert with, or in opposition to, other plant hormones. For example, the ratio of auxin to cytokinin in certain plant tissues determines

neg: Organic photorefractive materials other dopant molecules to be discussed in terms of PR effect. According to the literature, design strategy of hole conductors is mainly p-type based and the issues on the sensitizing are accentuated on n-type electron accepting materials, which are usually of very low content in the blends and thus do not provide a complementary path for electron conduction. In recent publications on organic PR materials, it is common to incorporate a polymeric material with charge transport units in its main or side chain. In this way, the polymer also serves as a host matrix to provide the resultant composite material

neg: Electron transport chain proton pumps; others are not. Most oxidases and reductases are proton pumps, but some are not. Cytochrome "bc" is a proton pump found in many, but not all, bacteria (it is not found in "E. coli"). As the name implies, bacterial "bc" is similar to mitochondrial "bc" ("Complex III"). Proton pumps are the heart of the electron transport process. They produce the transmembrane electrochemical gradient that enables ATP Synthase to synthesize ATP. Cytochromes are pigments that contain iron. They are found in two very different environments. Some cytochromes are water-soluble carriers that shuttle electrons to and from large, immobile macromolecular

neg: Mitochondrial matrix The oxidation of NADH and FADH produces GTP from succinyl-CoA synthetase. NADH and FADH2 are produced in the matrix or transported in through porin and transport proteins in order to undergo oxidation through oxidative phosphorylation. NADH and FADH2 undergo oxidation in the electron transport chain by transferring a electrons to regenerate NADand FAD. Protons are pulled into the intermembrane space by the energy of the electrons going through the electron transport chain. Four electrons are finally accepted by oxygen in the matrix to complete the electron transport chain. The protons return to the mitochondrial matrix through the protein ATP synthase.The

neg: Kjer's optic neuropathy cell death. Mitochondria are subcellular structures that generate and transform energy from metabolism into discrete usable units (ATP) for the cell’s functions ("See oxidative phosphorylation, electron transport chain"). Retinal ganglion cells (neurons), which make up the optic nerve, have a high energy demand and are particularly sensitive to mitochondrial dysfunction. This is especially the case for smaller and less myelinated neurons such as those found in the papillomacular bundle of the retina, which transmit information corresponding to the central visual field. Biochemical and mitochondrial morphological studies on cells from patients affected by autosomal dominant optic atrophy have shown a severe

neg: Evolutionary history of plants parts of the plant from the wet soil to avoid desiccation. Even today, water transport takes advantage of the cohesion-tension property of water. Water can be wicked along a fabric with small spaces, and in narrow columns of water, such as those within the plant cell walls or in tracheids, when molecules evaporate from one end, they pull the molecules behind them along the channels. Therefore, transpiration alone provides the driving force for water transport in plants. However, without dedicated transport vessels, the cohesion-tension mechanism can cause negative pressures sufficient to collapse the water conducting cells, limiting the transport water

neg: Angomonas deanei undergone alterations such as reduced paraflagellar rod, which is required full motility of the bacterial flagella. Yet the paraflagellar rod gene "PFR1" is fully functional. The bacteria are known to provide essential nutrients to the host, and provide electron transport system for the production of cellular energy, the ATP molecules through its glycosomes. The bacteria synthesise amino acids, vitamins, and haem for the protozoan. In return the protozoan offers its enzymes for the complete metabolic pathways for the biosysnthesis of amino acids, lipids and nucleotides, that are absent in the bacterium. Phosphatidylinositol, a membrane lipid required for cell-cell interaction, in

neg: Radio frequency welding of a molecule. This can leave regions of negative charge where electron densities are high and positive charge where electron densities are low. A simple example of this is a water molecule where the high electronegativity of Oxygen creates a negative pole by the Oxygen atom and a positive pole by the Hydrogen atoms. Using this same principal when analyzing a (CHCl) PVC molecule, a higher electron density would exist near the Cl atom in each unit of its polymer chain leading to a non-uniform distribution of charges and therefore a dipole would exist in PVC molecules. This makes PVC

neg: Oxidative phosphorylation removed from NADH and passed to oxygen through a series of enzymes that each release a small amount of the energy. This set of enzymes, consisting of complexes I through IV, is called the electron transport chain and is found in the inner membrane of the mitochondrion. Succinate is also oxidized by the electron transport chain, but feeds into the pathway at a different point. In eukaryotes, the enzymes in this electron transport system use the energy released from the oxidation of NADH to pump protons across the inner membrane of the mitochondrion. This causes protons to build up in

neg: Low-density lipoprotein of fatty acid molecules, there is a distribution of LDL particle mass and size. Determining the structure of LDL has been a tough task because of its heterogeneous structure. The structure of LDL at human body temperature in native condition, with a resolution of about 16 Angstroms using cryogenic electron microscopy, has been recently described. LDL particles are formed as VLDL lose triglyceride through the action of lipoprotein lipase (LPL) and they become smaller and denser (i.e. fewer fat molecules with same protein transport shell), containing a higher proportion of cholesterol esters. When a cell requires additional cholesterol (beyond its

neg: Human mitochondrial genetics cases, some mitochondria or a mitochondrion from the sperm cell enters the oocyte but paternal mitochondria are actively decomposed. Genes in the "human mitochondrial genome" are as follows. It was originally incorrectly believed that the mitochondrial genome contained only 13 protein-coding genes, all of them encoding proteins of the electron transport chain. However, in 2001, a 14th biologically active protein called humanin was discovered, and was found to be encoded by the mitochondrial gene MT-RNR2 which also encodes part of the mitochondrial ribosome (made out of RNA): Unlike the other proteins, humanin does not remain in the mitochondria, and interacts

neg: Plant hormone Plant hormone Plant hormones (also known as phytohormones) are signal molecules produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of growth and development, from embryogenesis, the regulation of organ size, pathogen defense, stress tolerance and through to reproductive development. Unlike in animals (in which hormone production is restricted to specialized glands) each plant cell is capable of producing hormones. The term 'phytohormone' was coined by Went and Thimann and used in the title of their book in 1937. Phytohormones are found across the plant kingdom, and even in algae, where they have similar functions

neg: Dihydrolipoyl transacetylase parts of the cell. In eukaryotes, glycolysis occurs in the cytoplasm, pyruvate decarboxylation in the mitochondria, the citric acid cycle within the mitochondrial matrix, and oxidative phosphorylation via the electron transport chain on the mitochondrial cristae. Thus pyruvate dehydrogenase complexes (containing the dihydrolipoyl transacetylase enzymes) are found in the mitochondria of eukaryotes (and simply in the cytosol of prokaryotes). Pyruvate decarboxylation requires a few cofactors in addition to the enzymes that make up the complex. The first is thiamine pyrophosphate (TPP), which is used by pyruvate dehydrogenase to oxidize pyruvate and to form a hydroxyethyl-TPP intermediate. This intermediate is taken

neg: High Affinity K+ transporter HAK5 cells. By controlling potassium, the HAK5 potassium transporter plays this important role in osmosis, and creates large influxes of water molecules to the plant to ensure its survival. By increasing the affinity of potassium uptake within the plant, it lowers the concentration of water within the cell. This increases the concentration of solute outside, creating a hypotonic solute. The water will then move into the plant cell via osmosis. A cell membrane consists of many transport proteins that allow for ion transport, as ions can not simply pass through the gradient due to their charge. High Affinity K transporter HAK5,

neg: Lipid emulsion delays the opening of mPTP in vivo rat models, making it a potential cardioprotective agent Lou et al. (2014) found that the cardioprotection aspect of Intralipid is initiated by the accumulation of acylcarnitines in the mitochondria and involves inhibition of the electron transport chain, an increase in ROS production during early (3 min) reperfusion, and activation of the reperfusion injury salvage kinase pathway (RISK). The mitochondrial accumulation of acylcarnitines (primarily palmitoyl-carnitine) inhibits the electron transport chain at complex IV, generating protective ROS. The effects of ROS are both “site” and “time” sensitive, meaning that both will ultimately determine whether the

neg: Photodissociation water molecules has been converted to four protons released into the thylakoid lumen (Dolai's S-state diagrams). These protons, as well as additional protons pumped across the thylakoid membrane coupled with the electron transfer chain, form a proton gradient across the membrane that drives photophosphorylation and thus the generation of chemical energy in the form of adenosine triphosphate (ATP). The electrons reach the P700 reaction center of photosystem I where they are energized again by light. They are passed down another electron transfer chain and finally combine with the coenzyme NADP and protons outside the thylakoids to form NADPH. Thus, the

neg: Iain McCulloch (academic) side-chain interdigitation and the use of non-covalent interactions to facilitate highly ordered self-assembly from solution have been widely adopted. Since moving to academia, he further advanced the understanding of charge transport in organic polymer thin films through exploring the role of backbone conformational restrictions on energetic disorder and charge carrier mobility. In the field of organic solar cells, McCulloch elucidated new design strategies for electron-accepting semiconducting molecules and optimised for both light absorption and electron transport, which has led to significant advances in power conversion efficiencies His approach focuses on controlled crystallisation through astute molecular functionality in precise locations on

neg: Oxidative phosphorylation transport chain, from electron donors such as NADH to electron acceptors such as oxygen, is an exergonic process – it releases energy, whereas the synthesis of ATP is an endergonic process, which requires an input of energy. Both the electron transport chain and the ATP synthase are embedded in a membrane, and energy is transferred from electron transport chain to the ATP synthase by movements of protons across this membrane, in a process called "chemiosmosis". In practice, this is like a simple electric circuit, with a current of protons being driven from the negative N-side of the membrane to the

neg: Mitochondrial matrix that contains the complexes of oxidative phosphorylation. which contains the electron transport chain that is found on the cristae of the inner membrane and consists of four protein complexes and ATP synthase. These complexes are Protein complex I (NADH:Coenzyme Q Oxidoreductase), protein complex II (Succinate:Coenzyme Q Oxidoreductase), protein complex III (Coenzyme Q: Cytochrome C Oxidoreductase), and protein complex IV (Cytochrome C Oxidase). The electron transport chain is responsible for establishing a pH and electrochemical gradient that facilitates the production of ATP through the pumping of protons. The gradient also provides control of the concentration of ions such as Ca driven

neg: Electron transport chain and archaea) the situation is more complicated, because there are several different electron donors and several different electron acceptors. The generalized electron transport chain in bacteria is: Note that electrons can enter the chain at three levels: at the level of a dehydrogenase, at the level of the quinone pool, or at the level of a mobile cytochrome electron carrier. These levels correspond to successively more positive redox potentials, or to successively decreased potential differences relative to the terminal electron acceptor. In other words, they correspond to successively smaller Gibbs free energy changes for the overall redox reaction "Donor →

neg: Membrane transport protein also help the body function in important ways. Cytochromes operate in the electron transport chain as carrier proteins for electrons. A number of inherited diseases involve defects in carrier proteins in a particular substance or group of cells. Cysteinuria (cysteine in the urine and the bladder) is such a disease involving defective cysteine carrier proteins in the kidney cell membranes. This transport system normally removes cysteine from the fluid destined to become urine and returns this essential amino acid to the blood. When this carrier malfunctions, large quantities of cysteine remain in the urine, where it is relatively insoluble and

neg: Light-dependent reactions with astonishingly high efficiency. Electrons are removed from excited chlorophyll molecules and transferred through a series of intermediate carriers to "ferredoxin", a water-soluble electron carrier. As in PS II, this is a solid-state process that operates with 100% efficiency. There are two different pathways of electron transport in PS I. In "noncyclic electron transport", ferredoxin carries the electron to the enzyme ferredoxin reductase (FNR) that reduces to NADPH. In "cyclic electron transport", electrons from ferredoxin are transferred (via plastoquinone) to a proton pump, cytochrome ". They are then returned (via plastocyanin) to P700. NADPH and ATP are used to synthesize