RNA, Transcription, and the Genetic Code. RNA. RNA = ribonucleic acid Nucleic acid similar to DNA but with several differences. *Uracil replaces Thymine in RNA and base pairs with Adenine!. RNA. Types of RNA: Messenger RNA (mRNA) - carries DNA message out of nucleus to ribosomes
*Uracil replaces Thymine in RNA and base pairs with Adenine!
Before mRNA strand is sent out of the nucleus. Non-coding parts need to be taken out through RNA splicing.
Introns= Non-coding segments, taken out
Exons= Coding segments, spliced together
mRNA Splicing Video
Codon = every three letters on an mRNA strand.
* Genetic code is degenerate since 64 different combinations of letter code for only 20 different amino acids. That means that most amino acids can be specified by more than one codon.
Important codons are start and stop:
Start = AUG
Stop = UAA, UGA, UAG