1. Cell Growth and Reproduction, and Protein Synthesis

2. Cell Growth and Reproduction Cell Life Cycle –Interphase G 1, S, G 2 DNA replication –Mitosis Prophase, Metaphase, Anaphase, Telophase Cytokinesis

3. Protein Synthesis Role of RNA –mRNA, tRNA, rRNA Transcription –Making mRNA complement –Editing mRNA Translation

5. DNA Synthesis

8. General Information One gene-one polypeptide hypothesis –Bridge RNA DNA  RNA  Protein Transcription –Synthesis of RNA under direction of DNA Translation –Actual synthesis of a polypeptide

11. DNA vs. RNA DNA –Sugar is deoxyribose –Nitrogenous bases A, G, C, and T RNA –Sugar is ribose –Nitrogenous bases A, G, C, and U –3 types mRNA rRNA tRNA

12. Transcription (Overview) Info is copied from DNA to RNA Copy = protein building instruction –mRNA Occurs in nucleus –mRNA then leaves nuclear envelope

13. Translation (Overview) Occurs in cytoplasm –On ribosomes Translation of mRNA into amino acid sequence

15. Triplet Code Gene  Protein based on triplet code Need mRNA first 3 nucleotide bases code for a single amino acid –Called a codon Must be read correctly –Ordering called the reading frame

17. Transcription RNA polymerase Three steps –Polymerase binding and initiation –Elongation –Termination

18. Polymerase Binding and Initiation Promoters –Initiation site for transcription Transcription factors –Aids polymerase in finding promoter region Polymerase –Separates two DNA strands

21. Elongation of RNA strand Polymerase separates double helix –Exposes DNA for transcription Transcription simultaneous

23. Termination of Transcription Termination site on DNA –RNA strand released –AATAAA site in eukaryotes mRNA editing –Introns must be removed spliceosomes

27. Translation tRNA –Transfers amino acids to a ribosome –Contains the anticodon –Builds polypeptide codon by codon Occurs on ribosomes –Contains rRNA –P site, A site, E site (not shown in the following pictures)

29. Translation Three stages –Chain initiation –Chain elongation –Chain termination Energy required for initiation and elongation (GTP)

30. Initiation mRNA, tRNA, and ribosomes come together GTP required to form initiation complex tRNA goes from A site to P site –A site ready for next tRNA

31. Elongation Amino acids added one by one Three step cycle –Codon recognition –Peptide bond formation –Translocation

35. Termination Termination codon –UAA, UAG, UGA Release factor in A site –Bond broken Between tRNA in P site and last amino acid of polypeptide chain –Polypeptide and tRNA free

38. Functional Protein Polypeptide coils and folds –3-D structure forms Some posttranslational modifications may be required