alleryStart learning →How many commonly occurring amino acids make up the protein alphabet?
ASixteen amino acids
BTwenty amino acids
CSixty-four amino acids
DSixty-one amino acids
Answer & Solution
Correct answer: B. Twenty amino acids
1. Protein sequences are built from 20 commonly occurring amino acids, so the protein alphabet has 20 letters.
2. Sixteen is the number of possible two-nucleotide combinations, not the number of amino acids.
3. Sixty-four counts the possible nucleotide triplets, and 61 of those triplets specify amino acids.
4. Only the count of 20 answers the question asked.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 15 "Genes and Proteins", section 15.1 The Genetic Code_
Keep practising Genes and Proteins
Browse all Genes and Proteins questions for CSIR NET, or explore more Biology topics.
Related questions
How long does the E. coli translation apparatus take to add one amino acid?Tetracycline blocks the A site of a bacterial ribosome. Which step does that stop?What do chaperone molecules do during protein folding?What does a signal sequence do for a newly made protein?What kind of catalyst is peptidyl transferase, and where does it sit?In what order does a charged tRNA pass through the three compartments of the ribosome?Which ribosomal site does the initiator tRNA occupy as the initiation complex forms?In the Kozak consensus around a vertebrate start codon, which bases can occupy the R posit