Aminoacids are the building blocks of proteins which are vital for the body to perform metabolic functions. They are categorised into three: 1. Essential aminoacids-cannot be synthesized by the body and hence obtained from the food we take. eg:histidine, isoleucine, leucine, lysine, methionine, phenyl alanine, thrionine,tryptophan and valine. 2. Non essential aminoacids- synthesized within the body. eg:alanine, asparagine, aspartic acid and glutamic acid. They can be synthesized from a nitrogen source.Eg: Synthesis of glutamic acid from ammonia and -ketoglutarate, catalysed by the enzyme glutamate dehydrogenase. 3. Conditional aminoacids-synthesized by the body under conditions of illness and stress.eg:arginine, cysteine, glutamine, glycine, proline, serine and tyrosine. Arginine is synthesized by mammals during the urea cycle. But the quantity synthesized is not enough to meet the metabolic needs of infants and children. Cysteine is derived from methionine, an essential amino acid. Tyrosine is derived from hydroxylation of phenyl alanine. Hence the essential aminoacids cannot be formed from other aminoacids, cannot be synthesized from nitrogen sources (unlike non-essential aminoacids) and cannot be synthesized by the body despite high calory intake. They cannot be synthesized in adequate amount to meet body needs.So the correct answer is Option d. Solution Aminoacids are the building blocks of proteins which are vital for the body to perform metabolic functions. They are categorised into three: 1. Essential aminoacids-cannot be synthesized by the body and hence obtained from the food we take. eg:histidine, isoleucine, leucine, lysine, methionine, phenyl alanine, thrionine,tryptophan and valine. 2. Non essential aminoacids- synthesized within the body. eg:alanine, asparagine, aspartic acid and glutamic acid. They can be synthesized from a nitrogen source.Eg: Synthesis of glutamic acid from ammonia and -ketoglutarate, catalysed by the enzyme glutamate dehydrogenase. 3. Conditional aminoacids-synthesized by the body under conditions of illness and stress.eg:arginine, cysteine, glutamine, glycine, proline, serine and tyrosine. Arginine is synthesized by mammals during the urea cycle. But the quantity synthesized is not enough to meet the metabolic needs of infants and children. Cysteine is derived from methionine, an essential amino acid. Tyrosine is derived from hydroxylation of phenyl alanine. Hence the essential aminoacids cannot be formed from other aminoacids, cannot be synthesized from nitrogen sources (unlike non-essential aminoacids) and cannot be synthesized by the body despite high calory intake. They cannot be synthesized in adequate amount to meet body needs.So the correct answer is Option d..

1. Aminoacids are the building blocks of proteins which are vital for the body to perform metabolic
functions. They are categorised into three:
1. Essential aminoacids-cannot be synthesized by the body and hence obtained from the food we
take. eg:histidine, isoleucine, leucine, lysine, methionine, phenyl alanine, thrionine,tryptophan
and valine.
2. Non essential aminoacids- synthesized within the body. eg:alanine, asparagine, aspartic acid
and glutamic acid. They can be synthesized from a nitrogen source.Eg: Synthesis of glutamic
acid from ammonia and -ketoglutarate, catalysed by the enzyme glutamate dehydrogenase.
3. Conditional aminoacids-synthesized by the body under conditions of illness and
stress.eg:arginine, cysteine, glutamine, glycine, proline, serine and tyrosine.
Arginine is synthesized by mammals during the urea cycle. But the quantity synthesized is not
enough to meet the metabolic needs of infants and children. Cysteine is derived from methionine,
an essential amino acid. Tyrosine is derived from hydroxylation of phenyl alanine.
Hence the essential aminoacids cannot be formed from other aminoacids, cannot be synthesized
from nitrogen sources (unlike non-essential aminoacids) and cannot be synthesized by the body
despite high calory intake. They cannot be synthesized in adequate amount to meet body
needs.So the correct answer is Option d.
Solution
Aminoacids are the building blocks of proteins which are vital for the body to perform metabolic
functions. They are categorised into three:
1. Essential aminoacids-cannot be synthesized by the body and hence obtained from the food we
take. eg:histidine, isoleucine, leucine, lysine, methionine, phenyl alanine, thrionine,tryptophan
and valine.
2. Non essential aminoacids- synthesized within the body. eg:alanine, asparagine, aspartic acid
and glutamic acid. They can be synthesized from a nitrogen source.Eg: Synthesis of glutamic
acid from ammonia and -ketoglutarate, catalysed by the enzyme glutamate dehydrogenase.
3. Conditional aminoacids-synthesized by the body under conditions of illness and
stress.eg:arginine, cysteine, glutamine, glycine, proline, serine and tyrosine.
Arginine is synthesized by mammals during the urea cycle. But the quantity synthesized is not
enough to meet the metabolic needs of infants and children. Cysteine is derived from methionine,
an essential amino acid. Tyrosine is derived from hydroxylation of phenyl alanine.
Hence the essential aminoacids cannot be formed from other aminoacids, cannot be synthesized
from nitrogen sources (unlike non-essential aminoacids) and cannot be synthesized by the body

2. despite high calory intake. They cannot be synthesized in adequate amount to meet body
needs.So the correct answer is Option d.