Search results
Results from the WOW.Com Content Network
In enzymology, a carboxylate reductase (EC 1.2.99.6) is an enzyme that catalyzes the chemical reaction. an aldehyde + acceptor + H 2 O a carboxylate + reduced acceptor. The 3 substrates of this enzyme are aldehyde, acceptor, and H 2 O, whereas its two products are carboxylate and reduced acceptor.
The carboxylate anion (R−COO − or R−CO − 2) of a carboxylic acid is usually named with the suffix -ate, in keeping with the general pattern of -ic acid and -ate for a conjugate acid and its conjugate base, respectively. For example, the conjugate base of acetic acid is acetate.
For example, the pK a value of acetic acid is 4.8, while ethanol has a pK a of 16. Hence acetic acid is a much stronger acid than ethanol. Hence acetic acid is a much stronger acid than ethanol. This in turn means that for equimolar solutions of a carboxylic acid or an alcohol in water, the carboxylic acid would have a much lower pH .
The final step in the reduction of carboxylic acids and esters is hydrolysis of the aluminium alcoxide. [8] Esters (and amides) are more easily reduced than the parent carboxylic acids. Their reduction affords alcohols and amines, respectively. [9] The idealized equation for the reduction of an ester by lithium aluminium hydride is:
The chemical mechanism is the same as in the browning of food, but it develops slowly over time due to the acidic action on the bog body. It is typically seen on Iron Age bodies and is the result of the interaction of anaerobic, acidic, and cold (typically 4 °C (39 °F)) sphagnum acid on the polysaccharides .
Decarboxylation. Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO 2).Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain.
The Dakin oxidation (or Dakin reaction) is an organic redox reaction in which an ortho- or para-hydroxylated phenyl aldehyde (2-hydroxybenzaldehyde or 4-hydroxybenzaldehyde) or ketone reacts with hydrogen peroxide (H 2 O 2) in base to form a benzenediol and a carboxylate. Overall, the carbonyl group is oxidised, whereas the H 2 O 2 is reduced.
TPP is the key catalytic cofactor used by enzymes catalyzing non-oxidative and oxidative decarboxylation of α-keto acids. Pyruvate, for example, undergoes both types of decarboxylation, both involving TPP. In fermentative organisms, pyruvate is non-oxidatively decarboxylated by the TPP-dependent enzyme pyruvate decarboxylase.