Introduction to protein structure: Difference between revisions

Proteins are condensation polymers of amino acids.  The <scene name='57/575866/Primary_sequence/2'>primary structure</scene> is the amino acid sequence, from the N terminus to the C terminus of the protein.  The <scene name='57/575866/Secondary_sequence/1'>secondary structure</scene> is the local structure over short distances.  This level of structure is stabilized by <scene name='57/575866/H_bond_a_helix/3'>hydrogen bonds</scene> along the <scene name='57/575866/Backbone/2'>backbone</scene>.  These secondary structures <scene name='57/575866/Global_secondary_structures/1'>pack together</scene> to form the overall form of the entire peptide chain, called the <scene name='57/575866/Tertiary/1'>tertiary structure</scene>.  Some proteins, such as the displayed hemoglobin molecule, have more than one polypeptide chain that associate to form the functional unit of the protein; this is called <scene name='57/575866/Tertiary/2'>quaternary structure</scene>.