Differences in gene expression in eukaryotes and prokaryotes

How are introns spliced

1. The 2’ OH group of a sugar attack the 5’ splice site of an intron

2. It will attach and form a loop (lariat)

3. The 3’ OH group which is released will attack the 3’ splice site

4. Lariat loop is removed and exons join together

Definition of a gene

• Region of DNA that is transcribed + corresponds to a set of related proteins generates by variant post-transcriptional processing/ single RNA

Eukaryotic mRNA modification

• 5’ cap

• Addition of 7-methylguanosine to the 5’ end

• Poly-A tail at the 3’ site

What do transcription factors do

• Identify the promoter sequence

• Help polymerase bond to the promoter sequence

Differences between transcription in eukaryotes and prokaryotes