What are primary, secondary, tertiary, and quaternary structure in proteins?
Primary structure is the amino acid sequence. Secondary structure includes basic protein folds such as alpha helices and beta sheets. Tertiary structure describes how the alpha helices and beta sheets fit together. Quaternary structure is only present when more than one peptide subunit is present. It describes how the multiple subunits fit together (tetramer, dimer, etc.). 2. Draw a peptide bond between two amino acids. Note: These bonds form the main chain of a protein and are not broken easily. Proteolytic enzymes or strong acid or base are required. 3. What is the charge of the N-terminus and C-terminus of the protein? A. The N-terminus is positively-charged at neutral pH, and is the conventional starting point of a protein. The N-terminus is synthesized first in the process of translation (converting mRNA to the protein it encodes). The C-terminus is the “end” of a peptide chain and is normally negatively-charged at neutral pH. There is only one N-terminus and one C-terminus per pe
