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In these conversions, phosgene is used in excess to increase yield and minimize side reactions. The phosgene excess is separated during the work-up of resulting end products and recycled into the process, with any remaining phosgene decomposed in water using activated carbon as the catalyst. Diisocyanates are precursors to polyurethanes. More ...
Lysine. Technically, any organic compound with an amine (–NH 2) and a carboxylic acid (–COOH) functional group is an amino acid. The proteinogenic amino acids are a small subset of this group that possess a central carbon atom (α- or 2-) bearing an amino group, a carboxyl group, a side chain and an α-hydrogen levo conformation, with the exception of glycine, which is achiral, and proline ...
Protein precursors are often used by an organism when the subsequent protein is potentially harmful, but needs to be available on short notice and/or in large quantities. Enzyme precursors are called zymogens or proenzymes. Examples are enzymes of the digestive tract in humans. Some protein precursors are secreted from the cell.
Essential genes in Mycobacterium tuberculosis H37Rv as found by using transposons which insert in random positions in the genome. If no transposons are found in a gene, the gene is most likely essential as it cannot tolerate any insertion. In this example, essential heme biosynthetic genes hemA, hemB, hemC, hemD are devoid of insertions. The ...
The adenylation activity is catalyzed by the bifunctional adenylyltransferase/adenylyl removal (AT/AR) enzyme. Glutamine and a regulatory protein called PII act together to stimulate adenylation. [3] This diagram shows the biosynthesis (anabolism) of amino acids glutamate, glutamine, proline, and arginine from the precursor alpha-ketoglutarate.
Measures include the biological value, net protein utilization, protein efficiency ratio, protein digestibility corrected amino acid score and the complete proteins concept. These concepts are important in the livestock industry , because the relative lack of one or more of the essential amino acids in animal feeds would have a limiting effect ...
At the top level are all alpha proteins (domains consisting of alpha helices), all beta proteins (domains consisting of beta sheets), and mixed alpha helix/beta sheet proteins. While most proteins adopt a single stable fold, a few proteins can rapidly interconvert between one or more folds. These are referred to as metamorphic proteins. [5]
Essential for humans, Val behaves similarly to isoleucine and leucine. Tryptophan: W Trp Essential for humans, Trp behaves similarly to phenylalanine and tyrosine. It is a precursor of serotonin and is naturally fluorescent. Unknown X Xaa Placeholder when the amino acid is unknown or unimportant. Tyrosine: Y Tyr