RNA stands for riboncleic acid. mRNA is messenger RNA. This type of RNA is a linear polymer involed in a part of protein symthesis called transcription. It allows the DNA code to be taken outside the nucleus to the cytoplasm to the ribosomes for translation. The enzyme RNA polymerase joins conmplementary bases together so a complementary copy to the DNA strand is made. The complementary bases in DNA and RNA are the smae apart A in DNA codes for U in RNA. rRNA is transfer RNA. tRNA is a clover leaf shape molecule of RNA. It is still single stranded but forms intramolecular base pairs so double stranded parts fo the molecule can be seen. Its involved in translation of mRNA in the cytoplasm of the cell. Its uses complementary anticodons to the codons on mRNA to bring the correct amino acid to the ribosomes so they can be condensed together and the polypeptide formed.