You should also know the ionizations shown in Table 2-1 on page 23, but you do not have to learn the exact pK values for each. Since proteins are made of amino acids, and because amino acid metabolism and protein synthesis are covered later on, the amino acid structures will be useful throughout the course. You should be able to tell D from L amino acids. Primary structure of a protein is the linear sequence of amino acids in the protein. This is unique for each protein, and comes from sequences stored in the DNA genes.
Secondary structure is repeated small-scale structure.
Tertiary structure often includes various sorts of secondary structure. Understand the pictures and text on 34-35. Both contain a tightly packed, lipophilic interior. Quaternary structure requires that there be more than one protein chain. The different colors are entirely separate proteins, that spontaneously associate with each other in tetramers.