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An ester of a carboxylic acid. R stands for any group (typically hydrogen or organyl) and R ′ stands for any organyl group. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (R ′). [1]
Esterases cleave ester bonds in lipids and phosphatases cleave phosphate groups off molecules. An example of crucial esterase is acetylcholine esterase , which assists in transforming the neuron impulse into the acetate group after the hydrolase breaks the acetylcholine into choline and acetic acid . [ 1 ]
Specifically, it is the phosphodiester bonds that link the 3' carbon atom of one sugar molecule and the 5' carbon atom of another (hence the name 3', 5' phosphodiester linkage used with reference to this kind of bond in DNA and RNA chains). [3] The involved saccharide groups are deoxyribose in DNA and ribose in RNA.
Phosphomonoesters (or phosphoric esters) are chemical compounds containing one ester bond and a phosphate group. In biology, phosphomonoesters are needed as the building blocks for the synthesis of Phospholipid cellular membranes, especially those found on neurons. [1] Enzymes which cleave these bonds are known as phosphomonoesterases, or ...
In acid-catalyzed Fischer esterification, the proton binds to oxygens and functions as a Lewis acid to activate the ester carbonyl (top row) as an electrophile, and converts the hydroxyl into the good leaving group water (bottom left). Both lower the kinetic barrier and speed up the attainment of chemical equilibrium.
General structure of a thionoester, where R and R' are organyl groups, or H in the case of R Skeletal formula of methyl thionobenzoate. Thionoesters are isomeric with thioesters. In a thionoester, sulfur replaces the carbonyl oxygen in an ester. Methyl thionobenzoate is C 6 H 5 C(S)OCH 3.
The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base. The reaction produces a β-keto ester or a β-diketone. [1] It is named after Rainer Ludwig Claisen, who first published his work on the reaction in 1887.
The amino acid is coupled to the terminal nucleotide at the 3’-end of the tRNA (the A in the sequence CCA) via an ester bond. The formation of the ester bond conserves a considerable part of the energy from the activation reaction. This stored energy provides the majority of the energy needed for peptide bond formation during translation.