What is mRNA?

mRNA is one of the 3 types of RNA: the others being tRNA and rRNA. They all play a role in protein synthesis. mRNA stands for messenger ribonucleic acid. It is made by copying a strand of DNA called the template strand. It is different to DNA as it is made from a different sugar (ribose) and it is single-stranded. Also instead of the base thymine, mRNA has uracil. mRNA is read by the ribosomes and used to synthesis proteins. The code is read 3 bases at a time: this is a triplet. Each triplet codes for 1 amino acid. Each triplet is also known as a codon. There are specific codons which signal the start of a new gene. These are called start codons, such as AUG.