1. Transcription and Translation How the Information in DNA Is Used to Build a Protein

2. DNA RNA Protein Information Flow From DNA transcription translation replication (S phase) (G1 and G2 phases) phases)

3. Transcription Initiation and Elongation Transcription begins at the promoter region

4. Transcription Termination

5. RNA Transcription Base in DNA Base in RNA AU TA GC CG Transcription = production of RNA using DNA as a template

6. RNA Transcription RNA Transcription requires 1. RNA polymerase, an enzyme that adds 1. RNA polymerase, an enzyme that adds nucleotides in a 5’  3’ direction. nucleotides in a 5’  3’ direction. 2. energy 2. energy 3’---TACAAAGAGACT---5’ 5’---ATG TTTCTC TGA---3’ 3’---TACAAA GAGACT---5’ DNA template 5’---ATG TTTCTC TGA---3’ 5’---AUGUUUCUCUGA---3’ mRNA

7. Applying Your Knowledge What is the sequence of an RNA molecule transcribed from a DNA template strand that reads 3’-ATG-5’? 1.5’-TAC-3’ 2.5’-CAU-3’ 3.5’-AUG-3’ 4.5’-UAC-3’ 5.3’-TAC-5’

8. RNA Transcription Three types of RNA are produced: Messenger RNA (mRNA)Messenger RNA (mRNA) Transfer RNA (tRNA)Transfer RNA (tRNA) Ribosomal RNA (rRNA)Ribosomal RNA (rRNA)

9. RNA Transcription Messenger RNAMessenger RNA Contains the code words for the sequence of amino acids in a specific protein CODON = group of three nucleotides acting as a code word for an amino acid CODON = group of three nucleotides acting as a code word for an amino acid

10. RNA Transcription Transfer RNATransfer RNA “Translates” the message by bringing a specific amino acid into the correct position on the growing protein chain Has ANTICODON = a group of three nucleotides on a tRNA that recognizes a mRNA codon Has amino acid attachment site mRNA

11. Genetic Code Chart is written as a CODON dictionary

12. RNA Transcription Ribosomal RNARibosomal RNA One of the structural components of the ribosome One of the structural components of the ribosome Ribosome = organelle where protein synthesis occurs Has sites to bind both mRNA and tRNA small ribosomal subunit for tRNA mRNA binding site

13. Applying Your Knowledge Which molecule contains the information for assembling the amino acids in the correct order in the protein? 1.rRNA 2.tRNA 3.mRNA 4.All of these 5.None of these

14. Interrupted Genes Eukaryotic Genes have interruptions within regions coding for protein intron = interrupting sequence exon = portion of coding region

15. Interrupted Genes Introns snipped out exons DNA introns promoter Transcription from DNA to RNA Initial transcript Splicing completed mRNA transcript

16. mRNA Processing DNA Add 5’ cap intron 1 intron 2 Exon 1 Exon 2 Exon 3 G intron 1 intron 2 Exon 1 Exon 2 Exon 3 G AAAAAAAA…… Remove Introns Splice Exons together together Add 3’ poly-A tail Transcription Exon 1 Exon 2 Exon 3 GAAAAAAAA…… Primary transcript RNA intron 1 intron 2 Exon 1 Exon 2 Exon 3 5’ 3’ Mature mRNA leaves for cytoplasm In nucleus

17. Applying Your Knowledge A poly-A tail (repeating sequence of adenine nucleotides) is added to _____ of the primary transcript. 1.The 3’ end 2.The 5’ end 3.Either the 3’ end or the 5’ end 4.Both the 3’ end and the 5’ end 5.Neither the 3’ end nor the 5’ end

18. Applying Your Knowledge Which of the following molecules lacks introns? 1.Primary transcript RNA 2.DNA 3.Mature messenger RNA 4.All of these lack introns 5.None of these lack introns

19. Protein Translation At the ribosome, codons in mRNA are recognized by tRNA anticodons to place amino acids in the specific sequence specified by the DNA. Three Stages of Translation: Initiation- assemble components to start process Initiation- assemble components to start process Elongation- add amino acids in repeated cycles Elongation- add amino acids in repeated cycles Termination- release protein product Termination- release protein product

20. Protein Translation Initiation mRNA binds to ribosome mRNA binds to ribosome First tRNA binds to mRNA First tRNA binds to mRNA 5’---AUGUUUCUCUGA---3’ mRNA UAC met

21. Protein Translation Elongation Next tRNA binds to mRNA Next tRNA binds to mRNA 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA

22. Protein Translation Elongation Amino acids are joined Amino acids are joined First tRNA is released First tRNA is released 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA

23. Protein Translation Elongation Ribosome moves by one codon Ribosome moves by one codon 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA

24. Protein Translation Elongation (second cycle) Next tRNA binds to mRNA Next tRNA binds to mRNA 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAAGAG leu

25. Protein Translation Elongation (second cycle) Amino acids are joined Amino acids are joined Second tRNA is released Second tRNA is released 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA GAG leu

26. Protein Translation Elongation (second cycle) Ribosome moves by one codon Ribosome moves by one codon 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA GAG leu

27. Protein Translation Termination Termination factor binds to stop codon Termination factor binds to stop codon 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA GAG leu T

28. Protein Translation Termination Protein chain is released Protein chain is released Other components separate Other components separate 5’---AUGUUUCUCUGA---3’ mRNA UAC metphe AAA GAG leu T

29. Applying Your Knowledge If the mRNA sequence for codons 5, 6, and 7 of a protein is 5’-AAG-AUU-GGA-3’, what is the amino acid sequence in the protein? 1.Gly-ile-lys 2.Arg-leu-glu 3.Glu-leu-arg 4.Asn-met-gly 5.Lys-ile-gly