Cell Division and Gene Expression

1. Cell Division and Gene Expression The Need for Cell Reproduction - The Nature of Chromosomes - The Cell Cycle - Mitosis and Cytokinesis - Cancer Cells: Abnormal Cell Cycle The Expression of Genes as Proteins: DNA gene --> RNA --> Protein - Transcription by RNA Polymerase (DNA gene --> mRNA) - The Three Types of RNA - Translation by Ribosome

2. Transcription • RNA polymerase • Enzyme that oversees synthesis of mRNA • Unwinds DNA template • Adds complementary RNA nucleotides on DNA template and joins them together • Stops when it reaches termination signal • mRNA pulls off the DNA template, is further processed by enzymes, and enters cytosol

3. Transcription: From DNA to RNA • In transcription, Genetic information is transferred from DNA to RNA (an RNA molecule is transcribed from a DNA template) GCAAATGCTGGCCGGAATCTAGGACTGC CGTTTACGA CCGGCCTTAGATCCTGACG GCAAATGCTGGCCGGAATCTAGGACTGC CGTTTACGA CCGGCCTTAGATCCTGACG U C G U A A A G C RNA Polymerase Makes a complementary copy of RNA from DNA Transcription

4. Cell Division and Gene Expression The Need for Cell Reproduction - The Nature of Chromosomes - The Cell Cycle - Mitosis and Cytokinesis - Cancer Cells: Abnormal Cell Cycle The Expression of Genes as Proteins: DNA gene --> RNA --> Protein - Transcription by RNA Polymerase - The Three Types of RNA - Translation by Ribosome

5. 3 Types of RNA – Each With a Different Job Messenger RNA (mRNA) Carries copy of gene information to the ribosome to make protein anticodon Transfer RNA (tRNA) CUG = C U G Carries amino acids to the ribosome for linking; identified by anticodon “sign” Part of the structure of the ribosome; key component in amino acid linking machinery Ribosomal RNA (rRNA)

6. Anatomy of a Messenger RNA Trailer Leader Figure 10.17

7. Cell Division and Gene Expression The Need for Cell Reproduction - The Nature of Chromosomes - The Cell Cycle - Mitosis and Cytokinesis - Cancer Cells: Abnormal Cell Cycle The Expression of Genes as Proteins: DNA gene --> RNA --> Protein - Transcription by RNA Polymerase - The Three Types of RNA - Translation by Ribosome - The Genetic Code

8. How Gene Instructions are Communicated

9. mRNA Codon Dictionary of the Genetic Code SECOND BASE U C A G U UUU UCU UAU UGU Tyr Cys Phe C UUC UCC UAC UGC U Ser A UUA UCA UAA Stop UGA Stop Leu G UUG UCG UAG Stop UGG Trp U CUU CCU CAU CGU His C CUC CCC CAC CGC C Leu Pro Arg A CUA CCA CAA CGA Gln G CUG CCG CAG CGG U AUU ACU AAU AGU Asn Ser C Ile AUC ACC AAC AGC A Thr A AUA ACA AAA AGA Lys Arg Met or G AUG ACG AAG AGG Start U GUU GCU GAU GGU Asp C GUC GCC GAC GGC G Val Ala Gly A GUA GCA GAA GGA Glu G GUG GCG GAG GGG

10. Central Dogma: DNARNAProtein DNA template strand: CGTTTACGACCGGCCTTAGATCCTGACG Transcription by RNA polymerase mRNA: GCAAAUGCUGGCCGGAAUCUAGGACUGC Translation by ribosome Protein: Met - Leu - Ala - Gly - Ile Translation

11. Cell Division and Gene Expression The Need for Cell Reproduction - The Nature of Chromosomes - The Cell Cycle - Mitosis and Cytokinesis - Cancer Cells: Abnormal Cell Cycle The Expression of Genes as Proteins: DNA gene --> RNA --> Protein - Transcription by RNA Polymerase - The Three Types of RNA - Translation by Ribosome -The Genetic Code -The Three Steps of Translation: Initiation, Elongation, & Termination

12. Simplified Diagram of a Ribosome Transcription has 3 parts: Initiation, where the ribosome assembles with mRNA Elongation, where the protein chain grows Termination, where the new protein is released

13. Translation Initiation Growing amino acid chain (polypeptide) tRNA E P A mRNA Termination Elongation

14. The Big Picture Regarding DNA->RNA -> Protein Figure 10.10

15. Cell Division and Gene Expression The Need for Cell Reproduction - The Nature of Chromosomes - The Cell Cycle - Mitosis and Cytokinesis - Cancer Cells: Abnormal Cell Cycle The Expression of Genes as Proteins: DNA gene --> RNA --> Protein - Transcription by RNA Polymerase - The Three Types of RNA - Translation by Ribosome