Multiple choice

Which of the following is an α-amino acid?

  1. Citric acid

  2. Citronella oil

  3. Citronellal

  4. Citrulline

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The organic compound citrulline is an α-amino acid. Although citrulline is not coded for by DNA directly, several proteins are known to contain citrulline as a result of a posttranslational modification.