Answer:
1)Protein is composed of amino acid.
We can identify protein by sequencing amino acids in peptide.
Carbohydrates is primarily avilabke energy source.
2) Proteins and nucleic acids are made up of C H O But carbohydrates and lipids consist of C H O N.
3)Nucleic acid DNA and RNA store and transmit genetic information from one generation to next generation.
Nucleic acid as present in body therefore not considered as essential nutrients.So dietary sources are plant and animal foods like meat fish vegetables etc.