Question 23M.2.HL.TZ2.a

1. composed of one or more polypeptides / some are single polypeptides others made of 2 or more polypeptide chains / all proteins consist of, at least, one polypeptide chain;
2. a polypeptide/protein is a chain of amino acids;
3. (chains of) amino acids linked by peptide bonds;
4. twenty different amino acids/ amino acids have different R groups/ R groups can be hydrophilic/polar or hydrophobic/non-polar;
5. primary structure is the sequence/order (and number) of amino acids in the polypeptide;
6. any sequence/order of amino acids could be linked together hence many possible polypeptides/proteins;
7. secondary structure is the formation of alpha/ α helices and beta/ β pleated sheets;
8. secondary structure stabilized by hydrogen bonding;
9. tertiary structure is the further folding of the polypeptide / tertiary structure is the three-dimensional (3-D) conformation/structure/shape of a protein;
10. tertiary structure stabilized by interactions / ionic bonds/hydrogen bonds/disulfide bridges between R groups;
11. fibrous or globular are the two main classes of conformation/three-dimensional/ 3-D structure/shape;
12. conformation/three-dimensional (3-D) structure determined by amino acid sequence;
13. quaternary structure if two or more polypeptides are linked to form a (single) protein
    OR
    quaternary structure if a prosthetic group is linked (to form a conjugated protein);

Accept clearly annotated diagrams.

Mpc: accept a clearly annotated diagram of the bond between 2 drawn amino acids.