Type of RNA
There are three types of RNA involved in gene expression.
mRNA - Messenger RNA:
- linear molecule
- carries a copy of the gene to be expressed from the nucleus
- every group of three bases (a 'triplet') is described as a codon (because each one codes for an amino acid)
tRNA - Transfer RNA:
- cloverleaf-shaped molecule
- is made from a single strand of RNA which folds due to base pairing to form this unusual shape
- has a triplet anti-codon site and an attachment site for a specific amino acid
rRNA - Ribosomal RNA:
- rRNA and proteins form the ribosome
- the ribosome is the structure where protein synthesis takes place