RNA (ribonucleic acid) is a nucleic acid that plays an important role in building proteins (protein synthesis).
The structure of RNA is very similar to the structure of DNA, which is also a nucleic acid.
However, in RNA, the nitrogenous base (nucleotide base) uracil replaces thymine, which can be found in DNA.
The five-carbon sugar in DNA is deoxyribose; it is ribose in RNA. Ribose contains an extra oxygen atom.
Some viruses are made of RNA.
Protein Synthesis
RNA takes the information stored in DNA and uses it to create proteins.
First, in a process known as transcription, an enzyme known as RNA polymerase is used to copy a DNA strand to create a complementary copy of RNA, following DNA's rules for base pairs, but substituting uracil for thymine in the RNA.
This form of RNA is known as messenger RNA (mRNA).
The mRNA then travels from the cell's nucleus to the cytoplasm (the area outside the nucleus of a eukaryotic cell), where it carries the genetic information to ribosomes, cell organelles where proteins are manufactured.
During the process of translation, the ribosomes use the genetic information that was carried in the mRNA to put together amino acids in specific sequences to form proteins.
Another type of RNA, known as transfer RNA (tRNA), brings the amino acids to the ribosomes.