1. Eukaryotic Gene Expression

2. Eukaryotes: Have a nuclear envelope
Many are multicellular with specialized cells
All cells have full sets of chromosomes
Not all genes need to be turned on (expressed)

3. Vocabulary: Euchromatin – uncoiled DNA (chromatin) found in eukaryotes
Intron – Not expressed!
-left over from evolutionary ancestors.
-May be turned on in related species
but not in us
Exon- genes that are expressed and code for
polypeptides

5. Vocabulary:
Enhancer – similar to regulator in prokaryotes, can initiate gene expression Transcription factor – assists in the placement of RNA polymerase on the promoter Promotor – DNA segment where RNA polymerase attaches to begin transcription

6. Gene expression in eukaryotes:
RNA polymerase is on the promoter
Transcription factor attaches to the enhancer, bending the DNA until it is next to the promoter.
Transcription factors on each side of RNA polymerase move it along the structural gene.

7. 4. DNA is transcribed (introns and exons are both copied) forming pre-mRNA 5. Introns are removed by splicesomes and exons are joined forming mRNA 6. Cap and Tail are attached, mRNA leaves through the nuclear pore.