What are nucleic acids? Explain their functions in the synthesis of proteins.

Nucleic acids are biomolecules found in the nuclei of all living cells, as one of the constituents of chromosomes.Nucleic acids are consist of a sugar unit, a phosphate group and a nitrogen base unit. These contain two type of bases:
(i) Pyrimidine bases.
(ii) Purine bases.
These are two types of sugar units in nucleic acids:
(i) Ribose.
(ii) Deoxyribose.
Nucleic acids are also known as polynucleotides as they are long-chain polymers of nucleotides.
Depending upon the type of sugar unit, there are two types of nucleic acids:
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). 
Two main functions of nucleic acids are:
(i) DNA is responsible for the transmission of inherent characters from one generation to
the next. This process of transmission is called heredity.
(ii) Nucleic acids (both DNA and RNA) are responsible for protein synthesis in a cell.
Even though the proteins are actually synthesised by the various RNA molecules in a
cell, the message for the synthesis of a particular protein is present in DNA.