• 2022-06-19
    Which of the following amino acids does not exist in protein molecule
    A: cysteine
    B: histidine
    C: citrulline
    D: arginine
    E: lysine
  • C

    内容

    • 0

      The primary structure of a food protein molecule refers to a linear sequence of amino acids connected by hydrogen bonding.

    • 1

      Proteins are large biological molecules consist of which of the following amino acids?: D-α-amino acids|D-β-amino acids|L- and D-β-amino acids|L-α-amino acids|L-β-amino acids

    • 2

      The final products of digestion are ? A: fatty acids, starch, glucose B: protein, amino acids, glucose C: protein, fat, carbohydrate D: glucose, amino acids, fatty acids

    • 3

      The photoreceptor protein rhodopsin, which is the light-sensitive protein made by the rod cells in the retina, detects light by means of a small molecule, ________, which is attached to the protein by a covalent bond to a lysine side chain.

    • 4

      Found in the chromatin of all eukaryotic cells, histones have molecular weights between 11,000 and 21,000 and are very rich in the basic amino acids arginine and lysine which together make up about _____ of all the amino acid residues. A: 1/6 B: 1/5 C: 1/4 D: 1/3