Question

Which of the 20 amino acids are essential amino acids for an adult human?
A) 6
B) 10
C) 11
D) 14

Answer 1

Hint: Amino acids are organic compounds which are known to consist of amino group, carboxyl group and a specific R group. The most important role of amino acid is in synthesis of proteins.

Complete answer-
Amino acids are broadly classified into proteinogenic and non-proteinogenic amino acids. Proteogenic amino acids are those that make up proteins by joining together into chains of various lengths. Twenty two amino acids are known to be proteinogenic amino acids, out of which twenty are encoded by the genetic code and the remaining two are synthesized by unique mechanisms. Non-proteinogenic amino acids are those that are not encoded by the genetic code or synthesized by cellular machinery, they are produced by post translational modification of certain proteins. Another way in which amino acids can be classified are standard and non-standard amino acids. Standard amino acids are those that are encoded directly by the genetic code and non-standard amino acids are those that are not encoded by the genetic code. Amino acids can also be classified on the basis of their synthesis by the human body, out of the twenty standard amino acids humans are not capable of synthesizing ten amino acids which are known as essential amino acids. The rest of the amino acids are known as non-essential amino acids since they can be synthesized by humans.

So the correct option is B) 10.

Note-
Apart from the synthesis of proteins, amino acids play many other important roles such as precursors of certain neurotransmitters, precursor of heme, precursor of polyamines, etc. Thus serving as important biological compounds.