The structure of RNA is a single-stranded molecule made up of basic units called nucleotides that contain a nitrogenous base, a five-carbon sugar and a phosphate group. Although there is only one strand of RNA, as opposed to the two stranded double helix of DNA, it does not always follow a linear pattern. Sometimes the molecules form loops and the nitrogenous bases bond.
According to the website About, the structure of RNA is made up of three components, one of which is a five-carbon sugar called ribose sugar. One of the carbons of the ribose sugar is attached to a nitrogenous base, which is adenine, guanine, cytosine or uracil. Another of the carbons of the ribose sugar is attached to the phosphate group. Yet another carbon is attached to a hydroxyl group. According to Nature Education, this hydroxyl group in one nucleotide bonds to the phosphate group on another nucleotide, making a long string of RNA.
Different types of RNA molecules include messenger RNA, or mRNA; transfer RNA, or tRNA; ribosomal RNA, or rRNA; and MicroRNAs. These different RNA molecules play important roles, from transcription of DNA and translation of protein synthesis to binding RNA at special binding sites in ribosomes and regulating gene expression.