4. unwindsunzips RNA Polymerase unwinds and unzips DNA (but does not proof-read… why not?) Complementary NTP’s add to template DNA strand from 5’ to 3’ RNA Polymerase begins transcribing the DNA at a specific point RNA strand is identical to the non- coded DNA (and complementary to the template strand) EXCEPT FOR...

5. Deoxynucleotide (dNTP) Nucleotide (NTP) Dideoxynucleotide (ddNTP)

6. Same process Same process as Prokaryotes! After mRNA is transcribed from DNA then the mRNA has a different fate in prokaryotes and eukaryotes translating Prokaryotes immediately begin translating the mRNA. Eukaryotes must process it first.

7. mRNA Processing: intron/exon methyl cap poly-A tail No mRNA Processing

8. Viral DNA injected into cells nucleasesCells evolve nucleases in cytoplasm that chomp up any RNA or DNA out there Nucleases can’t get through the nuclear envelope so DNA is safe mRNA sent out into the cytoplasm must be protected –Methyl cap is a block –Poly A tail is a fuse mRNA is still chomped up into NTP’s and recycled, but the Poly A tail gives it some time

9. “non-coding DNA”Eukaryotic DNA is composed mostly of “non-coding DNA” (or “junk DNA”) –We’re still not entirely sure what it does –Was probably inserted by different viruses over time –The ultimate selfish gene just hitching a ride on a successful group of genes… introns exonsThe introns are the sections of DNA not expressed, the exons are the sections that are expressed (ex-ons are ex-pressed, get it?) SpliceosomeSpliceosome loops out the introns and snips them out So now we’ve got some mRNA that codes for a protein