1.7 Amino acids and polypeptides

primary structure

the specific linear sequence of amino acids in the protein

secondary structure

a type of protein structure where three different folds can occur in amino acid chains, depending on the R groups in the different amino acids

alpha helix

a type of secondary structure in proteins that appears as a tight twist

beta-pleated sheet

a type of secondary structure in proteins that appears as folded sheets, with a change in direction of the polypeptide chain

random coiling

a type of secondary structure in proteins that does not fit in as either a alpha helix or beta-pleated sheet

tertiary structure

the total irregular 3D folding of a protein held together by various bonds forming a complex shape

quaternary structure

the final level of protein structure in which multiple polypeptides join together to form a protein complex