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What are the 3 types of RNA called?

Messenger RNA - mRNA
Transfer RNA - tRNA
Ribosomal RNA - rRNA


Function of messenger RNA.

It carries the 'message' that codes for a particular protein from the nucleus to the cytoplasm.


Structure of messenger RNA.

Single stranded and just long enough to contain one gene.
Short lifetime and becomes degraded soon after used.


Function of transfer RNA.

Its an 'adapter' that matches amino acids to their codons.
Amino acids attach to their tRNA molecule by specific aminoacyl tRNA synthase enzymes.


Structure of transfer RNA.

About 80 nucleotides long.
It folds up by complementary base pairing to form a looped clover-leaf.
One end of the molecule there is the base sequences ACC, where the amino acid binds.
Middle loop there is triplet nucleotide sequences called anticodon.


How are transfer RNA highly specific?

Because each amino acid is attached to a tRNA adaptor with the appropriate anticodon.


Function of ribosomal RNA.

rRNA together with proteins form ribsomes which are the site of mRNA translation and protein synthesis.
Ribsomes have 2 subunits (small and large) and they're assembled in the nucleolus and exported into the cytoplasm.
rRNA is coded for by numerous genes in many different chromosomes.


What does the location of ribsome determine?

The production of proteins.
Ribsomes free in cytoplasm make proteins for use in the cell.
Ribsomes attached to the RER make proteins for export.