38. Fig. 20-3-1 Restriction site DNA Sticky end Restriction enzyme cuts sugar-phosphate backbones. 5 3 3 5 1
39. Fig. 20-3-2 Restriction site DNA Sticky end Restriction enzyme cuts sugar-phosphate backbones. 5 3 3 5 1 DNA fragment added from another molecule cut by same enzyme. Base pairing occurs. 2 One possible combination
40. Fig. 20-3-3 Restriction site DNA Sticky end Restriction enzyme cuts sugar-phosphate backbones. 5 3 3 5 1 One possible combination Recombinant DNA molecule DNA ligase seals strands. 3 DNA fragment added from another molecule cut by same enzyme. Base pairing occurs. 2
41. Fig. 20-9a Mixture of DNA mol- ecules of different sizes Power source Longer molecules Shorter molecules Gel Anode Cathode TECHNIQUE 1 2 Power source – + + –
44. Fig. 20-10 Normal allele Sickle-cell allele Large fragment (b) Electrophoresis of restriction fragments from normal and sickle-cell alleles 201 bp 175 bp 376 bp (a) Dde I restriction sites in normal and sickle-cell alleles of -globin gene Normal -globin allele Sickle-cell mutant -globin allele Dde I Large fragment Large fragment 376 bp 201 bp 175 bp Dde I Dde I Dde I Dde I Dde I Dde I
71. Fig. 18-6 DNA Signal Gene NUCLEUS Chromatin modification Chromatin Gene available for transcription Exon Intron Tail RNA Cap RNA processing Primary transcript mRNA in nucleus Transport to cytoplasm mRNA in cytoplasm Translation CYTOPLASM Degradation of mRNA Protein processing Polypeptide Active protein Cellular function Transport to cellular destination Degradation of protein Transcription
72. Fig. 18-8-1 Enhancer (distal control elements) Proximal control elements Poly-A signal sequence Termination region Downstream Promoter Upstream DNA Exon Exon Exon Intron Intron
73. Fig. 18-8-2 Enhancer (distal control elements) Proximal control elements Poly-A signal sequence Termination region Downstream Promoter Upstream DNA Exon Exon Exon Intron Intron Cleaved 3 end of primary transcript Primary RNA transcript Poly-A signal Transcription 5 Exon Exon Exon Intron Intron
74. Fig. 18-8-3 Enhancer (distal control elements) Proximal control elements Poly-A signal sequence Termination region Downstream Promoter Upstream DNA Exon Exon Exon Intron Intron Exon Exon Exon Intron Intron Cleaved 3 end of primary transcript Primary RNA transcript Poly-A signal Transcription 5 RNA processing Intron RNA Coding segment mRNA 5 Cap 5 UTR Start codon Stop codon 3 UTR Poly-A tail 3
75. Fig. 18-9-1 Enhancer TATA box Promoter Activators DNA Gene Distal control element
76. Fig. 18-9-2 Enhancer TATA box Promoter Activators DNA Gene Distal control element Group of mediator proteins DNA-bending protein General transcription factors
77. Fig. 18-9-3 Enhancer TATA box Promoter Activators DNA Gene Distal control element Group of mediator proteins DNA-bending protein General transcription factors RNA polymerase II RNA polymerase II Transcription initiation complex RNA synthesis
78. Fig. 18-10 Control elements Enhancer Available activators Albumin gene (b) Lens cell Crystallin gene expressed Available activators LENS CELL NUCLEUS LIVER CELL NUCLEUS Crystallin gene Promoter (a) Liver cell Crystallin gene not expressed Albumin gene expressed Albumin gene not expressed
79. Fig. 18-2 Regulation of gene expression trpE gene trpD gene trpC gene trpB gene trpA gene (b) Regulation of enzyme production (a) Regulation of enzyme activity Enzyme 1 Enzyme 2 Enzyme 3 Tryptophan Precursor Feedback inhibition
80. Fig. 18-3a Polypeptide subunits that make up enzymes for tryptophan synthesis (a) Tryptophan absent, repressor inactive, operon on DNA mRNA 5 Protein Inactive repressor RNA polymerase Regulatory gene Promoter Promoter trp operon Genes of operon Operator Stop codon Start codon mRNA trpA 5 3 trpR trpE trpD trpC trpB A B C D E
81. Fig. 18-3b-1 (b) Tryptophan present, repressor active, operon off Tryptophan (corepressor) No RNA made Active repressor mRNA Protein DNA
82. Fig. 18-3b-2 (b) Tryptophan present, repressor active, operon off Tryptophan (corepressor) No RNA made Active repressor mRNA Protein DNA
83. Fig. 18-4a (a) Lactose absent, repressor active, operon off DNA Protein Active repressor RNA polymerase Regulatory gene Promoter Operator mRNA 5 3 No RNA made lac I lacZ
84. Fig. 18-4b (b) Lactose present, repressor inactive, operon on mRNA Protein DNA mRNA 5 Inactive repressor Allolactose (inducer) 5 3 RNA polymerase Permease Transacetylase lac operon -Galactosidase lacY lacZ lacA lac I
85. Fig. 18-5 (b) Lactose present, glucose present (cAMP level low): little lac mRNA synthesized cAMP DNA Inactive lac repressor Allolactose Inactive CAP lac I CAP-binding site Promoter Active CAP Operator lacZ RNA polymerase binds and transcribes Inactive lac repressor lacZ Operator Promoter DNA CAP-binding site lac I RNA polymerase less likely to bind Inactive CAP (a) Lactose present, glucose scarce (cAMP level high): abundant lac mRNA synthesized
114. Fig. 20-12 DNA (template strand) TECHNIQUE RESULTS DNA (template strand) DNA polymerase Primer Deoxyribonucleotides Shortest Dideoxyribonucleotides (fluorescently tagged) Labeled strands Longest Shortest labeled strand Longest labeled strand Laser Direction of movement of strands Detector Last base of longest labeled strand Last base of shortest labeled strand dATP dCTP dTTP dGTP ddATP ddCTP ddTTP ddGTP
115. Fig. 20-12a DNA (template strand) TECHNIQUE DNA polymerase Primer Deoxyribonucleotides Dideoxyribonucleotides (fluorescently tagged) dATP dCTP dTTP dGTP ddATP ddCTP ddTTP ddGTP
116. Fig. 20-12b TECHNIQUE RESULTS DNA (template strand) Shortest Labeled strands Longest Shortest labeled strand Longest labeled strand Laser Direction of movement of strands Detector Last base of longest labeled strand Last base of shortest labeled strand
