5. Which of these amino acids would have a positive charge at pH 7.0? a) Lys
b) Asp
c) Met
d) Gly

6. Which of these amino acids has three nitrogen atoms in its structure? a) Lys
b) Arg
c) Tyr
d) Val

7. Beta sheets are an example of:
a) primary structure
b) secondary structure
c) tertiary