生化n解释（Biochemical n interpretation）.docVIP

生化n解释（Biochemical n interpretation） Interpretation of biochemical terms Structure and function of protein The peptide bond: amide bond of a molecule of amino acid and other amino acids by carboxyl off water molecules formed after Is called a peptide bond. Isoelectric point: the tendency or degree of dissociation of an amino acid or protein into positive ions and anions in an pH solution And so on, become facultative ions, point neutral, at this time pH of the solution is called the amino acid or protein and so on Electric point. In protein molecules, two or more peptide segments with two - stage structures are spatially adjacent to each other in two molecules, Form a special spatial conformation and play a special function called a motif. Domain: a protein with a relatively large molecular weight; the three - order structure can often be divided into a number of closely - structured regions and used for specific purposes The functions of these regions are called domains. Subunit: a complete three - stage structure formed by each peptide chain in the four - stage structure of a protein. Peptide unit: in peptides, 4 atoms in the peptide bond and on both sides of the carbon atoms in the same plane, Peptide unit. Protein denaturation: the conformational destruction of proteins under the influence of certain physical and chemical factors, thus altering the nature of proteins Chemical properties and biological activities are called protein denaturation. Structure and function of nucleic acid DNA denaturation: in the presence of some physical and chemical factors, DNA molecules are stabilized by double helix space conformation breaking and double stranded solutions Chain into two single chain, but its primary structure is still intact phenomenon called DNA degeneration. Tm: that is, the temperature of the solution or the temperature of the chain is the maximum absorption value of the nucleic acid when the nucleic acid is heated and denatured Temperature at 50%. At Tm, the