Nucleic Acids

Nucleic acids are macromolecules composed of chains of nucleotides. They contain coding information and are found in all living cells and viruses. There are two forms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

The role of DNA is the long-term store of genetic information:

• It is the means by which genetic information is passed from generation to generation. It is able to do this because it is capable of self-replication.
• It acts as a code, since it contains the instructions needed to construct other cell components, such as proteins and RNA. The code on DNA is represented by the sequences of bases in the nucleotides.

Lengths of DNA that carry the genetic information for the synthesis of proteins are called genes. Genes consist of nucleotides with a specific sequence of bases. The sequence of bases determines the sequence of amino acids in a polypeptide, coding for the order in which amino acids are brought together.

RNA molecules assist the functioning of DNA. They retrieve information from DNA and direct the synthesis of proteins. RNA molecules act as messengers between DNA in the nucleus and the sites of protein synthesis (the ribosomes) in the cytoplasm. They also form portions…