What is RNA

DNA is a type of nucleic acid. And in this video we are going to have a quick look at another type; RNA. We have both DNA and RNA in our bodies. We need them both! DNA is the blueprint; it contains all of the instructions for the cell to grow, function and replicate. The RNA carries out these instructions; it copies and transfers the genetic code from the DNA to ensure the relevant proteins are made. So just think of it as “DNA makes RNA make proteins”. Whereas DNA stands for deoxyribonucleic acid, RNA stands for ribonucleic acid. Whilst DNA is double stranded, RNA is single stranded. Like DNA, RNA is made up of a long chain of nucleotides. Each nucleotide consists of a ribose sugar, phosphate group and a nucleotide base. RNA has a sugar called ribose, whereas DNA has a sugar called deoxyribose. RNA has a base uracil, or U, whereas DNA has the base thymine or T. So in RNA C and G still pair, but now A and U pair. We need to know about RNA because we will see it when learning about protein synthesis. We will see two special types of RNA: messenger RNA which is known as mRNA. And transfer RNA which is known as tRNA. We will see the mRNA being synthesised inside the nucleus, copied from the DNA code. The tRNA is found in the cytoplasm. For many years, we just thought RNA was a DNA photocopier as mRNA, the protein builder as tRNA and found in ribosomes as rRNA. However, RNA can also act as enzymes to speed up chemical reactions. And in many viruses, they have RNA instead of DNA. The RNA carries the genetic code in these viruses.