NTDT200 Lecture Notes - Lecture 13: Disulfide, Globular Protein, Tangled
21 Feb 2018
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Document Summary
Protein: compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain; some amino acids also contain sulfur atoms. Peptide bond: a bond that connects the acid end of one amino acid with the amino end of another, forming a link in a protein chain. Polypeptide: many (10 or more) amino acids bonded together. The primary structure of a protein is determined by the sequence of amino acids. The secondary structure of proteins is determined by weak electrical attractions within the polypeptide chain. Ex: as positively charged hydrogens attract nearby negatively charged oxygens, sections of the polypeptide chain twist into a helix or fold into a pleated sheet. The tertiary structure of proteins occurs as long polypeptide chains twist and fold into a variety of complex, tangle shapes. Some amino acid side groups are attracted to water molecules- hydrophilic. Some amino acid side groups are repelled by water molecules- hydrophobic.
