Multiple choice

Which of the following amino acids was found in 2002?

  1. Lysine

  2. Hydroxyproline

  3. Pyrrolysine

  4. Alanine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pyrrolysine was discovered in 2002 as the 22nd genetically encoded amino acid, found in certain methanogenic archaea and bacteria. It is encoded by the stop codon UAG in these organisms. Lysine, hydroxyproline, and alanine were discovered much earlier and are standard amino acids.

Keep practicing — related questions