Problem : What is the product of eukaryotic transcription? Of prokaryotic? What is the difference between these two products?

Eukaryotic transcription yields pre-mRNA or primary transcript RNA. Prokaryotic transcription yields mature RNA (mRNA). While mRNA is ready to be translated into a protein sequence, primary transcript RNA must first undergo modifications before it can be transported out of the cell nucleus for translation.

Problem : What is the name of protein coding segments of primary transcript RNA? Of non- protein coding segments? Which are conserved during the splicing reaction?

Exons are segments of primary transcript RNA that are conserved during the splicing reaction and code for proteins during translation. Introns are sequences that are not conserved and are spliced out during the splicing reaciton.

Problem : How is an intron recognized so that it can be cut out during splicing?

Although the vast majority of an intron's sequence is unimportant, there are certain regions within an intron that allow it to be cut out. These regions consist of a 5' splice site, a 3' splice site, and a branch A point. These three regions interact during the splicing reaciton.

Problem : What is the role of snRRPs in the splicing reaction?

snRNPs are proteins that make up the spliceosome unit that guides the splicing reaction. Each of the five snRNPs plays a specific role in catalyzing a step in the splicing reaction.

Problem : What are the two forms of RNA editing that can take place before translation?

RNA editing can either be in the form of changing one base pair to another, or adding or deleting base pairs.