What is RNA Made Of?
RNA, or ribonucleic acid, is a fundamental molecule in all living cells. It's crucial for translating genetic information from DNA into proteins. But what exactly is it made of?
RNA is composed of smaller units called nucleotides. Each nucleotide consists of three parts:
- A ribose sugar: Unlike DNA, which uses deoxyribose sugar, RNA utilizes ribose sugar. This difference is a key structural distinction between the two nucleic acids.
- A phosphate group: This group links the ribose sugars together to form the RNA backbone. The alternating pattern of phosphate groups and ribose sugars creates the characteristic RNA chain.
- A nitrogenous base: Attached to each ribose sugar is one of four nitrogenous bases: adenine (A), uracil (U), cytosine (C), or guanine (G). These bases are crucial for encoding genetic information and forming the specific structure of RNA molecules. Note that RNA uses uracil (U) instead of thymine (T), which is found in DNA.
This combination of ribose sugar, phosphate group, and nitrogenous base creates the basic building block—the nucleotide—that makes up the RNA molecule. These nucleotides are linked together to form a single-stranded chain, in contrast to the double-stranded helix of DNA.
The RNA Backbone: Ribose and Phosphate
As stated in several references (https://www.ncbi.nlm.nih.gov/books/NBK558999/, https://www.genome.gov/genetics-glossary/RNA-Ribonucleic-Acid-%28RNA%29), the RNA backbone is a crucial structural feature. This backbone is formed by the alternating arrangement of phosphate groups and the ribose sugar molecules.
The Nitrogenous Bases: A, U, C, and G
The four nitrogenous bases (adenine, uracil, cytosine, and guanine) are attached to the ribose sugar in each nucleotide. These bases are responsible for RNA's ability to carry genetic information and participate in various cellular processes. (Refer to https://www.ncbi.nlm.nih.gov/books/NBK558999/ and https://www.nature.com/scitable/definition/rna-45/).
In summary, RNA is built from nucleotides containing a ribose sugar, a phosphate group, and one of four nitrogenous bases (A, U, C, or G). The order of these bases along the RNA strand determines its function and the genetic information it carries.
