Search results
Results from the WOW.Com Content Network
The Hopkins-Cole reaction, also known as the glyoxylic acid reaction, is a chemical test used for detecting the presence of tryptophan in proteins. [1] A protein solution is mixed with Hopkins Cole reagent, which consists of glyoxylic acid. Concentrated sulfuric acid is slowly added to form two layers. A purple ring appears between the two ...
The structure of glyoxylic acid is shown as having an aldehyde functional group. The aldehyde is only a minor component of the form most prevalent in some situations. Instead, glyoxylic acid often exists as a hydrate or a cyclic dimer. For example, in the presence of water, the carbonyl rapidly converts to a geminal diol (described as the ...
Glyoxylate and dicarboxylate metabolism describes a variety of reactions involving glyoxylate or dicarboxylates.Glyoxylate is the conjugate base of glyoxylic acid, and within a buffered environment of known pH such as the cell cytoplasm these terms can be used almost interchangeably, as the gain or loss of a hydrogen ion is all that distinguishes them, and this can occur in the aqueous ...
This acetate, bound to the active thiol group of coenzyme A, enters the citric acid cycle (TCA cycle) where it is fully oxidized to carbon dioxide. This pathway thus allows cells to obtain energy from fat. To use acetate from fat for biosynthesis of carbohydrates, the glyoxylate cycle, whose initial reactions are identical to the TCA cycle, is ...
The reaction relies on the interaction between glyoxylic acid and the indole ring of the amino acid tryptophan, a structural feature found in most proteins. When proteins are exposed to concentrated sulfuric acid and glyoxylic acid, the indole group undergoes a reaction that produces a highly colored compound.
It is a spontaneous reaction and a type of post-translational modification of proteins meaning it alters their structure and biological activity. It is the covalent attachment between the carbonil group of a reducing sugar (mainly glucose and fructose) and the amino acid side chain of the protein. In this process the intervention of an enzyme ...
This center, below and to the left of the pair in the diagram, contains four manganese ions, a calcium ion, a chloride ion, and a tyrosine residue. Manganese is adept at these reactions because it is capable of existing in four oxidation states: Mn 2+, Mn 3+, Mn 4+ and Mn 5+. Manganese also forms strong bonds with oxygen-containing molecules ...
The denaturing of proteins by an aqueous solution containing many types of ions is more complicated as all the ions can act, according to their Hofmeister activity, i.e., a fractional number specifying the position of the ion in the series (given previously) in terms of its relative efficiency in denaturing a reference protein.