Ribonucleic acid (RNA)

Definition

Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles, including coding, decoding, regulation, and expression of genes. It is typically single-stranded and composed of ribonucleotides linked by phosphodiester bonds.

5 Must Know Facts For Your Next Test

1. RNA contains the sugar ribose, unlike DNA which contains deoxyribose.
2. There are three main types of RNA involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
3. Uracil replaces thymine as one of the four nitrogenous bases in RNA.
4. RNA can act as a catalyst in biological reactions; such catalytic RNAs are known as ribozymes.
5. RNA is synthesized from DNA by the process of transcription.

Review Questions

• What sugar is found in the structure of RNA?
• Name the three main types of RNA involved in protein synthesis.
• What base does uracil replace in RNA?

Related terms

DNA:

Deoxyribonucleic acid, a double-stranded molecule that stores genetic information.

Transcription: The process by which an RNA molecule is synthesized from a DNA template.

Ribosome: A molecular complex that facilitates the translation of mRNA into proteins.