1 / 49

CHAPTER 9 REPLICATION TRANSCRIPTION TRANSLATION REGULATION

CHAPTER 9 REPLICATION TRANSCRIPTION TRANSLATION REGULATION. THE GENETIC MATERIAL. LIKE DNA, RNA IS A LONG CHAIN OF NUCLEIC ACIDS BUT THERE ARE SOME DIFFERENCES URACIL REPLACES THYMINE RIBOSE SUGAR REPLACES DEOXYRIBOSE. DNA is a DOUBLE helix. 3’ →5’. DNA REPLICATION.

zora
Download Presentation

CHAPTER 9 REPLICATION TRANSCRIPTION TRANSLATION REGULATION

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 9 REPLICATION TRANSCRIPTION TRANSLATION REGULATION

  2. THE GENETIC MATERIAL

  3. LIKE DNA, RNA IS A LONG CHAIN OF NUCLEIC ACIDS BUT THERE ARE SOME DIFFERENCES • URACIL REPLACES THYMINE • RIBOSE SUGAR REPLACES DEOXYRIBOSE

  4. DNA is a DOUBLE helix 3’→5’

  5. DNA REPLICATION

  6. DNA polymerase synthesizes DNA only in the 5’ to 3’ direction. This leads to continuous replication on one strand and short fragments on the other. DNA polymerase requires a primer to initiate synthesis. This is a short segment of RNA synthesized by RNA primase (an RNA polymerase)

  7. THE RAW MATERIALS FOR TRANSCRIPTION AND TRANSLATION

  8. LIKE DNA, RNA IS A CHAIN OF NUCLEIC ACIDS BUT THERE ARE SOME DIFFERENCES • RNA IS SINGLE STRANDED • RNA IS COPIED FROM A DNA TEMPLATE • THERE ARE THREE MAJOR TYPES OF RNA THAT ARE COPPIED FROM DNA • messenger RNA (mRNA) is a copy of a gene • transfer RNA (tRNA) carries an amino acid • ribosomal RNA (rRNA) is part of the ribosomes

  9. Transfer RNAs • Transfer RNAs • Structure • Copied from ca 20 genes, one/tRNA • Charged by attaching to an amino acid. • Each tRNA is charged with an amino acid specific for its anticodon • Pairs with mRNA on the ribosomes

  10. attaches to an amino acid that is specific for this particular tRNA pairs with messenger RNA

  11. VI. RIBOSOMAL RNAS • C. Ribosomal RNAS • Location of rRNA in cell: nucleolus • Ribosome subunits: 3 genes tandomly repeated • Combine with proteins to make large and small subunit ribosomes

  12. Ribosomal RNAs are found in a tandem repeat Chromosome Genes SSU Gene 5.8 S Gene LSU Gene 5S Gene Tandemly repeated sequence

  13. Structure of the ribosomal RNA repeat unit SSU Gene 5.8 S Gene LSU Gene 5S Gene Plus proteins ribosome small subunit Plus proteins ribosome large subunit

  14. Genes are on one side of the double helix Gene: A sequence of DNA that encodes a polypeptide Gene (blue) is on one strand of the DNA double helix

  15. Genes have a start codon and a stop codon Genes are segments of DNA along a strand of DNA. They have a start code and a stop codon (codon = a three base DNA sequence). Chromosome Genes Gene - enlarged Stop codon Start codon

  16. Control regions Exon = gene coding regions Introns = non gene regions Stop codon Start codon Poly A attachment site Promoter (RNA polymerase binds here)

  17. TRANSCRIPTION

  18. Transcription – RNA polymerase binds to the promoter TRANSCRIPTION Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon

  19. TRANSCRIPTION Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon

  20. mRNA PROCESSING

  21. Pre-mRNA is released PROCESSING Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon Pre-mRNA (Pre-messenger RNA)

  22. A 7-MG cap is attached PROCESSING Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon 7MG

  23. Introns are spliced out PROCESSING Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon 7MG INTRONS SPLICED OUT Cut at poly A recognition sequence

  24. A poly A tail is added PROCESSING Poly A attachment site Promoter (RNA polymerase binds here) Start codon Stop codon AAAA 7MG INTRONS SPLICED OUT Poly A tail added mRNA leaves the nucleus

  25. mRNA MOVES TO THE RIBOSOMES

  26. mRNA leaves the nucleus Ribosomal subunits mRNA AAA nucleus Cell membrane

  27. AAA Ribosomal subunits mRNA nucleus Cell membrane

  28. mRNA binds to the small ribosomal subunit AAA Ribosomal subunits mRNA nucleus Cell membrane

  29. The two ribosomal subunits join AAA Ribosomal subunits mRNA nucleus Cell membrane

  30. IV. mRNA PROCESSING mRNA IS TRANSLATED INTO A PROTEIN

  31. mRNA CODON CHART

  32. 3 1 2 A 6 5 4 A

  33. POLYPEPTIDES ARE SORTED

  34. In prokaryotes, linked genes may be copied into a single mRNA which is ten translated into different polypeptides

  35. PROKARYOTE GENE REGULATION

  36. The operon system of gene regulation in prokaryotes involves regulatory regions and linked genes that are co-regulated. For example, the Lac operon The Lac operon acts to import lactose into the cell and to break down lactose into glucose + galactose. Glucose is used in glycolysis and cellular respiration.

  37. EUKARYOTIC GENE REGULATION

  38. Eukaryotic genes are not organized into introns Instead, there are a number of regulatory regions, each responding to a different signal. protein “z” protein “y” xyz za xy

  39. END

More Related