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Histidine ball and stick model spinning. Histidine (symbol His or H) [2] is an essential amino acid that is used in the biosynthesis of proteins.It contains an α-amino group (which is in the protonated –NH 3 + form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO − form under biological conditions), and an imidazole side chain (which is partially ...
Histidine is thus able to act as a powerful general base, activating the serine nucleophile. The histidine base aids the first leaving group by donating a proton, and also activates the hydrolytic water substrate by abstracting a proton as the remaining OH − attacks the acyl-enzyme intermediate.
A sample nutrition facts label, with instructions from the U.S. Food and Drug Administration [1] Nutrition facts placement for two Indonesian cartons of milk The nutrition facts label (also known as the nutrition information panel, and other slight variations [which?]) is a label required on most packaged food in many countries, showing what nutrients and other ingredients (to limit and get ...
A polyhistidine-tag, best known by the trademarked name His-tag, is an amino acid motif in proteins that typically consists of at least six histidine (His) residues, often at the N- or C-terminus of the protein. It is also known as a hexa histidine-tag, 6xHis-tag, or His6 tag.
In enzymology, a histidine-tRNA ligase (EC 6.1.1.21) is an enzyme that catalyzes the chemical reaction. ATP + L-histidine + tRNAHis AMP + diphosphate + L-histidyl-tRNAHis. The 3 substrates of this enzyme are ATP, L-histidine, and tRNA(His), whereas its 3 products are AMP, diphosphate, and L-histidyl-tRNA(His).
“The FCC borrowed the nutrition label model format from food products because we wanted to make basic information about broadband internet service easily recognizable and easy to understand ...
In plants, the shikimate pathway first leads to the formation of chorismate, which is the precursor of phenylalanine, tyrosine, and tryptophan.These aromatic amino acids are the precursors of many secondary metabolites, all essential to a plant's biological functions, such as the hormones salicylate and auxin.
The two main systems in humans are the glycerol phosphate shuttle and the malate-aspartate shuttle. The malate/a-ketoglutarate antiporter functions move electrons while the aspartate/glutamate antiporter moves amino groups. This allows the mitochondria to receive the substrates that it needs for its functionality in an efficient manner. [1]