Amino Acid Quiz

1. Which one-letter symbol represents glycine?

2. A protein needs a side chain that is usually positively charged near physiological pH. Which residue best fits?

3. A kinase targets the hydroxyl-bearing residue in the segment A–S–L–G. Which symbol marks the likely phosphorylation site?

4. A sequence contains the shorter acidic side chain followed by the longer acidic side chain. Which pair of one-letter symbols represents that order?

5. Which set correctly gives the one-letter symbols for phenylalanine, tryptophan, and tyrosine, in that order?

6. A peptide segment is written as W–L–D. Which sequence of amino acid names matches it?

7. In a protein, glutamate (E) is replaced by glutamine (Q). What is the most direct side-chain change near neutral pH?

8. A researcher is looking for an amino acid with an imidazole side chain that can participate in proton transfer. Which amino acid fits?

9. What is the one-letter symbol for tryptophan?

10. The one-letter symbol Q stands for which amino acid?

11. Which standard amino acid is achiral because its side chain is a hydrogen atom?

12. A newly translated protein sequence begins with the one-letter symbol M. Which amino acid does M represent?

13. A residue will be buried in the hydrophobic interior of a soluble protein. Which amino acid is the best fit?

14. Two regions of a protein are linked by a disulfide bond. Which one-letter symbol identifies the residue that forms this linkage?

15. Which group consists entirely of the three branched-chain amino acids?

16. Which amino acid is represented by the one-letter symbol K?