Question: which are the 20 known amino acids?
Answer: alanine - ala - A (gif, interactive)
arginine - arg - R (gif, interactive)
asparagine - asn - N (gif, interactive)
aspartic acid - asp - D (gif, interactive)
cysteine - cys - C (gif, interactive)
glutamine - gln - Q (gif, interactive)
glutamic acid - glu - E (gif, interactive)
glycine - gly - G (gif, interactive)