1. You should be able to label these pictures Label the following: –RNA polymerase –DNA –mRNA –tRNA –5’ end –3’ end –Amino acid –Ribosome –Polypeptide chain –Codon –anticodon

2. Focus Question:  How does transcription work in prokaryotes and eukaryotes?  IB Topic 7.3 Transcription

3. The “Players”  DNA  RNA polymerase  mRNA  Ribosome  tRNA  Amino acids

4. Definition  Transcription- the reading and recording of DNA code.  Location: Nucleus

5. Direction of Transcription  Occurs in the 5’  3’ direction (with reference to the mRNA)

6. IB Terms: Sense vs. Antisense strands  Sense strand- the “other” strand, not transcribed.  Antisense strand- the one mRNA attaches to, and is complimentary to.  mRNA is similar to the sense strand, except T  U.

7. New…the “Middle” Step  Transcription- beginning  Middle = mRNA processing  Translation- end

8. RNA processing  Post-transcriptional  Introns- non-coding sequences are removed  Exons- coding sequences are spliced together

9. New Players: Prokaryotic Transcription  Promoter- place on gene where RNA polymerase initially attaches.  Terminator- place on gene where transcription ends.

10. RNA Nucleotides = Ribonucleoside Triphosphates  Similar to deoxynucleoside triphosphates. Serve as the building blocks for mRNA.  Can work from 5’ to 3’ OR 3’ to 5’