Search results
Results from the WOW.Com Content Network
The conversion uses N 2 O 4 and nitric acid at 5–10 °C in the liquid phase. After esterification and dehydration MMA is obtained. Challenges with this route, aside from yield, involve the handling of large amounts of nitric acid and NO x. This method was discontinued in 1965 after an explosion at an operation plant. [10]
The units were joined by condensation of the carboxylic acid group –C(=O)OH of one monomer with the amine group H 2 N− of the next one. Some biologically important oligomers are macromolecules like proteins or nucleic acids; for instance, hemoglobin is a protein tetramer. An oligomer of amino acids is called an oligopeptide or just a peptide.
Epoxide monomers may be cross linked with themselves, or with the addition of a co-reactant, to form epoxy; BPA is the monomer precursor for polycarbonate; Terephthalic acid is a comonomer that, with ethylene glycol, forms polyethylene terephthalate. Dimethylsilicon dichloride is a monomer that, upon hydrolysis, gives polydimethylsiloxane.
Methacrylic acid undergoes several reactions characteristic of α,β-unsaturated acids (see acrylic acid). These reactions include the Diels–Alder reaction and Michael additions . Esterifications are brought about by acid-catalyzed condensations with alcohols, alkylations with certain alkenes, and transesterifications.
Indeed, they can be viewed as a string of beads, with each bead representing a single nucleotide or amino acid monomer linked together through covalent chemical bonds into a very long chain. In most cases, the monomers within the chain have a strong propensity to interact with other amino acids or nucleotides.
A monopeptide has one amino acid. A dipeptide has two amino acids. A tripeptide has three amino acids. A tetrapeptide has four amino acids. A pentapeptide has five amino acids. (e.g., enkephalin). A hexapeptide has six amino acids. (e.g., angiotensin IV). A heptapeptide has seven amino acids. (e.g., spinorphin). An octapeptide has eight amino ...
Protein structure is the three-dimensional arrangement of atoms in an amino acid-chain molecule. Proteins are polymers – specifically polypeptides – formed from sequences of amino acids, which are the monomers of the polymer. A single amino acid monomer may also be called a residue, which indicates a
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. [1] Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. [2] Only these 22 appear in the genetic code of life. [3] [4]