RNA (ribonucleic acid) is an important macromolecule made up of subunits known as nucleotides. It plays a vital role in gene expression by acting as the intermediate between the genetic information encoded by DNA and proteins. The primary function of RNA is the synthesis of proteins.
RNA is single-stranded and has a backbone that is composed of alternating sugar (ribose) and phosphate groups. It is found in all biological cells and usually occurs in the cytoplasm of the cell although its synthesis takes place in the nucleus.
While DNA provides the code for the cell's activities, RNA is responsible for converting that code into proteins that carry out various cellular functions. There are three main types of RNA. Each has a specific function in protein synthesis:
- mRNA or Messenger RNA serves as an intermediary between DNA and directs the synthesis of proteins during translation.
- rRNA or Ribosomal RNA ensures that the mRNA, tRNA, and the ribosomes are properly aligned during protein synthesis. It also catalyzes the formation of peptide bonds between two aligned amino acids during protein synthesis.
- tRNA or transfer RNA transports the correct amino acids to the corresponding sites of protein synthesis in the ribosome.
In addition to its role in protein synthesis, RNA also performs other functions including:
- Regulation of gene expression
- Protein coding
- Production of regulatory molecules
- Development of gametes by the ncRNA (non-coding RNA)