Топ-100

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Rhodium carbonyl chloride

Rhodium carbonyl chloride is an organorhodium compound with the formula Rh 2 Cl 2 4. It is a red-brown volatile solid that is soluble in nonpolar organic solvents. It is a precursor to other rhodium carbonyl complexes, some of which are useful in ...

                                               

Ring-closing metathesis

Ring-closing metathesis, or RCM, is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the E- ...

                                               

Tetrakis(triphenylphosphine)palladium(0)

Tetrakispalladium is the chemical compound, often abbreviated Pd 4, or rarely PdP 4. It is a bright yellow crystalline solid that becomes brown upon decomposition in air.

                                               

Wacker process

The Wacker process or the Hoechst-Wacker process refers to the oxidation of ethylene to acetaldehyde in the presence of palladium chloride as the catalyst. This chemical reaction was one of the first homogeneous catalysis with organopalladium che ...

                                               

Xerotine siccative

Xerotine siccative was an oil drying agent used in the late 19th century. It is a type of terebene; unlike standard terebenes, xerotine siccative doesnt become cloudy when mixed in an oil. Replacing boiled oil, xerotine siccative was mixed with p ...

                                               

RAGATH RNA motifs

RNAs Associated with Genes Associated with Twister and Hammerhead ribozymes refers to a bioinformatics strategy that was devised to find self-cleaving ribozymes in bacteria. It also refers to candidate RNAs, or RAGATH RNA motifs, discovered using ...

                                               

Beta-globin co-transcriptional cleavage ribozyme

The Beta-globin co-transcriptional cleavage ribozyme was proposed to be an RNA enzyme known as a ribozyme. Transcription termination of RNA polymerase II transcripts is proposed to occur by a two-stage process. The first stage involves pre-termin ...

                                               

GlmS glucosamine-6-phosphate activated ribozyme

The glucosamine-6-phosphate riboswitch ribozyme is an RNA structure that resides in the 5 untranslated region of the mRNA transcript of the glmS gene. This RNA regulates the glmS gene by responding to concentrations of a specific metabolite, gluc ...

                                               

Group I catalytic intron

Group I introns are large self-splicing ribozymes. They catalyze their own excision from mRNA, tRNA and rRNA precursors in a wide range of organisms. The core secondary structure consists of nine paired regions. These fold to essentially two doma ...

                                               

Group II intron

Group II introns are a large class of self-catalytic ribozymes and mobile genetic elements found within the genes of all three domains of life. Ribozyme activity can occur under high-salt conditions in vitro. However, assistance from proteins is ...

                                               

Group III intron

Group III intron is a class of introns found in mRNA genes of chloroplasts in euglenid protists. They have a conventional group II-type dVI with a bulged adenosine, a streamlined dI, no dII-dV, and a relaxed splice site consensus. Splicing is don ...

                                               

Hairpin ribozyme

The hairpin ribozyme is a small section of RNA that can act as a ribozyme. Like the hammerhead ribozyme it is found in RNA satellites of plant viruses. It was first identified in the minus strand of the tobacco ringspot virus satellite RNA where ...

                                               

Hammerhead ribozyme

The hammerhead ribozyme is an RNA motif that catalyzes reversible cleavage and ligation reactions at a specific site within an RNA molecule. It is one of several catalytic RNAs known to occur in nature. It serves as a model system for research on ...

                                               

Hatchet ribozyme

The hatchet ribozyme is an RNA structure that catalyzes its own cleavage at a specific site. In other words, it is a self-cleaving ribozyme. Hatchet ribozymes were discovered by a bioinformatics strategy as RNAs Associated with Genes Associated w ...

                                               

Hepatitis delta virus ribozyme

The hepatitis delta virus ribozyme is a non-coding RNA found in the hepatitis delta virus that is necessary for viral replication and is the only known human virus that utilizes ribozyme activity to infect its host. The ribozyme acts to process t ...

                                               

GIR1 branching ribozyme

The Lariat capping ribozyme is a ~180 nt ribozyme with an apparent resemblance to a group I ribozyme. It is found within a complex type of group I introns also termed twin-ribozyme introns. Rather than splicing, it catalyses a branching reaction ...

                                               

Leadzyme

Leadzyme is a small ribozyme, which catalyzes the cleavage of a specific phosphodiester bond. It was discovered using an in-vitro evolution study where the researchers were selecting for RNAs that specifically cleaved themselves in the presence o ...

                                               

Ligase ribozyme

The RNA Ligase ribozyme was the first of several types of synthetic ribozymes produced by in vitro evolution and selection techniques. They are an important class of ribozymes because they catalyze the assembly of RNA fragments into phosphodieste ...

                                               

Pistol ribozyme

The pistol ribozyme is an RNA structure that catalyzes its own cleavage at a specific site. In other words, it is a self-cleaving ribozyme. The pistol ribozyme was discovered through comparative genomic analysis. Subsequent biochemical analysis d ...

                                               

Ribonuclease P

Ribonuclease P is a type of ribonuclease which cleaves RNA. RNase P is unique from other RNases in that it is a ribozyme – a ribonucleic acid that acts as a catalyst in the same way that a protein-based enzyme would. Its function is to cleave off ...

                                               

Ribosomal RNA

Ribosomal ribonucleic acid is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal DNA and t ...

                                               

Ribosome

Ribosomes are macromolecular machines, found within all living cells, that perform biological protein synthesis. Ribosomes link amino acids together in the order specified by the codons of messenger RNA molecules to form polypeptide chains. Ribos ...

                                               

RNase MRP

RNase MRP is an enzymatically active ribonucleoprotein with two distinct roles in eukaryotes. RNAse MRP stands for RNAse for mitochondrial RNA processing. In mitochondria it plays a direct role in the initiation of mitochondrial DNA replication. ...

                                               

Twister ribozyme

The twister ribozyme is a catalytic RNA structure capable of self-cleavage. The nucleolytic activity of this ribozyme has been demonstrated both in vivo and in vitro and has one of the fastest catalytic rates of naturally occurring ribozymes with ...

                                               

Twister sister ribozyme

The twister sister ribozyme is an RNA structure that catalyzes its own cleavage at a specific site. In other words, it is a self-cleaving ribozyme. The twister sister ribozyme was discovered by a bioinformatics strategy as an RNA Associated with ...

                                               

Vg1 ribozyme

The Vg1 ribozyme is a manganese dependent RNA enzyme or ribozyme which is the smallest ribozyme to be identified. It was identified in the 3′ UTR of Xenopus Vg1 mRNA transcripts and mouse beta-actin mRNA. This ribozyme was identified from in vitr ...

                                               

VS ribozyme

Varkud satellite VS ribozyme is the largest known nucleolyic ribozyme and found to be embedded in VS RNA. VS RNA is a long non-coding RNA exists as a satellite RNA and is found in mitochondria of Varkud-1C and few other strains of Neurospora. VS ...

                                               

ZACA reaction

The zirconium-catalyzed asymmetric carbo-alumination reaction was developed by Nobel laureate Ei-ichi Negishi. It facilitates the chiral functionalization of alkenes using organoaluminium compounds under the influence of chiral bis-indenylzirconi ...

                                               

Enzyme unit

The enzyme unit, or international unit for enzyme is a unit of enzymes catalytic activity. 1 U μmol/min is defined as the amount of the enzyme that catalyzes the conversion of one micromole of substrate per minute under the specified conditions o ...

                                               

Activated complex

In chemistry an activated complex is defined by the International Union of Pure and Applied Chemistry as "that assembly of atoms which corresponds to an arbitrary infinitesimally small region at or near the col of a potential energy surface". In ...

                                               

Aquilanti–Mundim deformed Arrhenius model

Arrhenius plots, which are used to represent the effects of temperature on the rates of chemical and biophysical processes and on various transport phenomena in materials science, may exhibit deviations from linearity. Account of curvature is pro ...

                                               

Arrhenius plot

In chemical kinetics, an Arrhenius plot displays the logarithm of a reaction rate constant, {\displaystyle \ln}, ordinate axis) plotted against reciprocal of the temperature. Arrhenius plots are often used to analyze the effect of temperature on ...

                                               

Collision frequency

Collision frequency describes the rate of collisions between two atomic or molecular species in a given volume, per unit time. In an ideal gas, assuming that the species behave like hard spheres, the collision frequency between A and B is: Z = n ...

                                               

Curtin–Hammett principle

The Curtin–Hammett principle is a principle in chemical kinetics proposed by David Yarrow Curtin and Louis Plack Hammett. It states that, for a reaction that has a pair of reactive intermediates or reactants that interconvert rapidly, each going ...

                                               

Elasticity coefficient

The rate of a chemical reaction is influenced by many different factors, such as temperature, pH, reactant and product concentrations and other effectors. The degree to which these factors change the reaction rate is described by the elasticity c ...

                                               

Entropy of activation

In chemical kinetics, the entropy of activation of a reaction is one of the two parameters which are typically obtained from the temperature dependence of a reaction rate constant, when these data are analyzed using the Eyring equation of the tra ...

                                               

Flash photolysis

Flash photolysis is a pump-probe laboratory technique, in which a sample is first excited by a strong pulse of light from a pulsed laser of nanosecond, picosecond, or femtosecond pulse width or by another short-pulse light source such as a flash ...

                                               

Hammonds postulate

Hammonds postulate, is a hypothesis in physical organic chemistry which describes the geometric structure of the transition state in an organic chemical reaction. First proposed by George Hammond in 1955, the postulate states that: If two states, ...

                                               

Kinetic chain length

In polymer chemistry the kinetic chain length of a polymer, ν, is the average number of units called monomers added to a growing chain during chain-growth polymerization. During this process, a polymer chain is formed when monomers are bonded tog ...

                                               

More OFerrall–Jencks plot

More O’Ferrall–Jencks plots are two-dimensional representations of multiple reaction coordinate potential energy surfaces for chemical reactions that involve simultaneous changes in two bonds. As such, they are a useful tool to explain or predict ...

                                               

Neighbouring group participation

Neighbouring group participation in organic chemistry has been defined by IUPAC as the interaction of a reaction centre with a lone pair of electrons in an atom or the electrons present in a sigma bond or pi bond contained within the parent molec ...

                                               

Non-thermal microwave effect

Non-thermal microwave effects or specific microwave effects have been posited in order to explain unusual observations in microwave chemistry. The main effect of the absorption of microwaves by most materials is heating; the random motion of the ...

                                               

Pressure jump

Pressure jump is a technique used in the study of chemical kinetics. It involves making rapid changes to the pressure of an experimental system and observing the return to equilibrium or steady state. This allows the study of the shift in equilib ...

                                               

Reaction progress kinetic analysis

In chemistry, reaction progress kinetic analysis is a subset of a broad range of kinetic techniques utilized to determine the rate laws of chemical reactions and to aid in elucidation of reaction mechanisms. While the concepts guiding reaction pr ...

                                               

Reaction rate constant

In chemical kinetics a reaction rate constant or reaction rate coefficient, k, quantifies the rate of a chemical reaction. For a reaction between reactants A and B to form product C A + B → C the reaction rate is often found to have the form: r = ...

                                               

Receptor–ligand kinetics

In biochemistry, receptor–ligand kinetics is a branch of chemical kinetics in which the kinetic species are defined by different non-covalent bindings and/or conformations of the molecules involved, which are denoted as receptor and ligand. Recep ...

                                               

Stern–Volmer relationship

The Stern–Volmer relationship, named after Otto Stern and Max Volmer, allows the kinetics of a photophysical intermolecular deactivation process to be explored. Processes such as fluorescence and phosphorescence are examples of intramolecular dea ...

                                               

Temperature jump

The temperature jump method is a technique used in chemical kinetics for the measurement of very rapid reaction rates. It is one of a class of chemical relaxation methods pioneered by the German physical chemist Manfred Eigen in the 1950s. In the ...

                                               

Thorpe–Ingold effect

The Thorpe–Ingold effect, gem-dimethyl effect, or angle compression is an effect observed in chemistry where large substituents favor ring closure and intramolecular reactions. The effect was first reported by Beesley, Thorpe, and Ingold in 1915 ...

                                               

Transition state

The transition state of a chemical reaction is a particular configuration along the reaction coordinate. It is defined as the state corresponding to the highest potential energy along this reaction coordinate. It is often marked with the double d ...