Question

In addition to essential amino acids, children require two more amino acids in their diet. They are
A. Arginine and leucine
B. Histidine and valine
C. Arginine and phenylalanine
D. Arginine and histidine.

Answer 1

Hint: In the animal body for the formation of the proteins some molecular forms are called amino acids. These are required for the formation of proteins in the body. There are more than 200 proteins that are formed in the body and these proteins are formed by 20 amino acids in the body. In an animal body, these amino acids join to form proteins.

Complete answer:
There are basically two types of amino acids which are required for the formation of proteins:
Essential Amino Acids- these are the amino acids that are diet essential i.e. they must be provided in the diet and not produced by the body of an animal itself. There are 9 essential amino acids out of a total of 20 amino acids i.e. valine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan these are eight essential amino acids required in adults, and the last essential amino acid which is histidine – needed in infants or children less than 10 years of age.
Non-essential amino acids- these are the amino acids that do not diet essential and produced by the body itself. These amino acids are not to be provided from outside the body. There are 11 non-essential amino acids i.e. arginine, glutamine, tyrosine, cysteine, glycine, proline, serine, ornithine, alanine, asparagine, and aspartate.
Option -A- Arginine and leucine
Arginine being non-essential amino acid but still needed by infants and leucine is provided in the diet but this option does not match the meta of the question.
Option -B- Histidine and valine
Histidine is a type of only essential amino acid that needs to be provided to infants but in this question is asked what extra amino acids to be provided along with essential amino acids so valine does not match the requirement of this question.
Option -C- Arginine, and phenylalanine
These two amino acids do not match the requirement of this question as phenylalanine is already an essential amino acid.
Option -D- Arginine, and histidine
As stated in this answer earlier Arginine is non-essential amino acid and Histidine is only essential amino acid to be given to infants only. So this option satisfies the needs of this question i.e. in addition to essential amino acids these need to be supplied in the diet to infants.

So, the correct answer to this question is the option “D” Arginine and Histidine.

Note: These amino acids are known to be the building blocks for proteins in the animal body. These proteins are required for various components of the body forming the structure of muscles, enzymes, etc.