1. Molecular Biology Informational Macromolecules DNA/RNA/PROTEINS Cells Chemical Machines Coding devices 8

2. Informational Flow REPLICATION: DNA/DNA TRANSCRIPTION: DNA/RNA (mRNA) TRANSLATION: mRNA (RIBOSOMES)/PROTEINS GENETIC CODE: TRIPLET NUCLEOTIDE BASE=AMINO ACID RIBOSOMES- SYNTHESIS MACHINERY

4. Polysystronic

6. Transcription DNA--------------------  RNA Types of RNA mRNA- Messenger tRNA- Transfer rRNA- ribosomal

7. DNA Versus RNA 1.Ribose sugar 2 C-OH 2.Pyrimidine Uracil/Thymine 3.Single Stranded (May have secondary Structures)

8. RNA Functions 1.Genetic- carry Genetic Information Transcribed From DNA Template 2. Functional: Macromolecule: Ribosomes or tRNA Catalytic Activity

10. Overview Transcription (DNA  mRNA) RNA Polymerases Varies with Bacteria, Archaea, Eucaryae Steps Involved Initiation Elongation Termination

11. RNA Polymerase One Type in cytoplasma DNA Dependant N.T Sequence codes for single polypeptide Chain “GENE” Transcribed to mRNA “Polycistronic” More than one gene coded at a time “Operons” Gene Cluster into 1 transcriptional Unit “REGULATION” PROMOTER SITE: START SITE NO PRIMER NECESSARY

12. P Initiation Site -10 -35 ORF 3’ 5’ 3’ Genes Antisense Strand Pribnow Box -35 TTGAGA -10 TATAAT RNA POLYMERASE BINDING Sigma  Regulation Operons 1 st nt

13. RNA Polymerase “HALOENZYMES” 5 SUBUNITS SIGMA 1 ST TO BIND TO PROMOTER Formation of Phosphodiester bonds (R.N.T) Must used AntiSense DNA Strand as Template rNTPS- ATP, CTP, UTP, GTP

14. TRANSCRIPTION INITIATION- PRIBNOW BOX- SIGMA- POLYMERASE TRANSCRIPTIONAL BUBBLE, PDE, PURINE 1 ST NT ELONGATION: ANTISENSE DNA SEQUENCE TERMINATION: 1. rho PROTEIN DEPENDANT (NT SEQUENCE RNA) 2. rho INDEPENDENT (HAIR PEN LOOP)

15. INITIATION

18. 1 st N.T Purine

21. TERMINATION Specific Sequences on DNA Strand Stops Transcription Two Ways: 1.Rho Dependant Protein- Sequence RNA Molecule 2.Rho Independent inverted repetes on DNA Molecule Hair pen Loop on RNA

24. rRNA Operon Spacer

25. Methylated (Ribonuclease)

28. TRANSLATION RNA---------  PROTEINS THREE TYPES RNA 1.mRNA 2.tRNA 3.rRNA

30. mRNA Linear Carries genetic info transcribed from DNA CODONS- 3 sequence n.t. coding for Amino Acids Short Lived, used Once dis-assimbled

31. tRNA 1.Transferring Agent to bring selected rNTP to rRNA 2.4 Loops “folded Clover leaf” 3.Amino Acid Binding site 3’ End 4.Anticodon- Determine AA Requested on mRNA 5.Energy Required- Amino Acyl-tRNA Synthetases

32. The structure of E. coli N-formyl-methionyl-tRNA fMet The structure of E. coli N-formyl-methionyl-tRNA fMet

33. Activation AA + ATP------------  AA-AMP P.P AA-AMP + RNA----------  AA-tRNA + AMP

35. r RNA 1.Acts as “Decoding Box” 2.Recognizes and holds mRNA in place 3.Forms peptide bond- AA. AA 4.Proof Reads for Accuracy

37. 16S rRNA Small Sub Unit Recognizes and Hold mRNA 23S rRNA Large Sub Unit Catalyzes Synthesis of AA.AA

38. Translation & Genetic Code Watson & Crick 1953 Unstable mRNA 1961 Genetic Code 1962

39. Gobind Khorana Nirenburg CODON 3 Letter N.T. Sequence = Amino Acid Conventional 5’------------  3’ N Terminus--------------C Terminus “GUG” Val “UGU” Cys

40. Degenerate 4 letter in alphabet Codes for 64 Amino Acids Multiple Codes for Some Amino Acids “Alanine” GCA GCC GCG GCU “Wobble Effect” Relax Code for 3 rd Letter

42. Start Codon ‘1” Universal for Bacteria “AUG” N-formylmethiomine STOP Codon (3) UAG UGA UGG

43. SYNTHESIS INITIATION ELONGATION TERMINATION

44. INITIATION SHINE-DALGARNO : AGG AGG START Sequence on 16S RNA mRNA Binds to AGG AGG to attach mRNA to 16SRNA at Start site- m RNA 5’-------  3’ Attachment Signs LSU rRNA to bind to SSU

45. ELONGATION 30s rRNA initiates binding on mRNA and 16S rRNA Complex Creates three Positions APE A= Aminoacyl_tRNA Synthetase P = Peptidyl Transferase E = Exit Site

49. Figure 13.15 (Part 2) Protein synthesis

51. Termination STOP CODONs UAA UAG or UGA Release Factors: RF 1, 2, or 3