© 2003 mark s. davis chapter 21 nucleic acids. © 2003 mark s. davis thanks mom… ishihara’s...
TRANSCRIPT
![Page 1: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/1.jpg)
© 2003 Mark S. Davis
Chapter 21
Nucleic Acids
![Page 2: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/2.jpg)
© 2003 Mark S. Davis
Thanks Mom…
• Ishihara’s simple test
• X-linked
• Easy to trace
![Page 3: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/3.jpg)
© 2003 Mark S. Davis
25
![Page 4: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/4.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 5: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/5.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 6: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/6.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 7: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/7.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 8: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/8.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 9: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/9.jpg)
© 2003 Mark S. Davis
What do you see?
![Page 10: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/10.jpg)
© 2003 Mark S. Davis
Thanks Dad ??? (not really)• Thalassemia• Hereditary in Mediterranean people• Defective hemoglobin• Beta thalassemia results in an excess of alpha
globins, which leads to the formation of alpha globin tetramers (4) that accumulate in the erythroblast (immature red blood cell). These aggregates are very insoluble and precipitation interferes with erythropoiesis, cell maturation and cell membrane function, leading to ineffective erythropoiesis and anemia.
![Page 11: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/11.jpg)
© 2003 Mark S. Davis
Queen Victoria
• Hemophilia
• Passed it on to several royal families in Europe
![Page 12: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/12.jpg)
© 2003 Mark S. Davis
Goals
• Describe nucleotides, RNA and DNA, polypeptides
• Know the 3D structure of nucleic acids
• Describe mutations and their effects
• Describe viruses and Recombinant DNA technology
![Page 13: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/13.jpg)
© 2003 Mark S. Davis
Chromosomes• Humans have 46
– Each cell is diploid
• Germ cells have 23– Called haploid– Contain one copy of each chromosome
• Contain all genetic information of the organism
• DNA
![Page 14: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/14.jpg)
© 2003 Mark S. Davis
![Page 15: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/15.jpg)
© 2003 Mark S. Davis
RNA
• Leave nucleus
• Direct protein synthesis
![Page 16: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/16.jpg)
© 2003 Mark S. Davis
Nucleotides
• Monomers that make up DNA and RNA
• DNA – 2-deoxy-D-ribose
• RNA – D-ribose
![Page 17: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/17.jpg)
© 2003 Mark S. Davis
Nucleotides
• Made from–Phosphoric acid
–Sugar
–Purine – bicyclic
–Pyrimidines – single ring
![Page 18: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/18.jpg)
© 2003 Mark S. Davis
Naming• Sugar and base
–Adenine + sugar = Adenosine
–Cytosine + sugar = Cytidine
• 5’ – monophosphate is second part of the name
• dGMP
![Page 19: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/19.jpg)
© 2003 Mark S. Davis
![Page 20: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/20.jpg)
© 2003 Mark S. Davis
![Page 21: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/21.jpg)
© 2003 Mark S. Davis
5’ – 3’ Phosphodiester
• In making DNA – dehydration occurs at C3 and phosphate group on C5
• This is the direction used for naming
![Page 22: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/22.jpg)
© 2003 Mark S. Davis
![Page 23: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/23.jpg)
© 2003 Mark S. Davis
DNA Structure
• Watson and Crick 1953
• Double helix – right handed
• Complementary pairs–A-T
–G-C
![Page 24: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/24.jpg)
© 2003 Mark S. Davis
![Page 25: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/25.jpg)
© 2003 Mark S. Davis
![Page 26: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/26.jpg)
© 2003 Mark S. Davis
Complementary Strands
• Bases located opposite
• Maximum hydrogen bonding
• Maximum stability
• Hydrophobic bonds to the bases above and below
![Page 27: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/27.jpg)
© 2003 Mark S. Davis
Given…
• G A T T A C A
• What is the complementary strand?
![Page 28: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/28.jpg)
© 2003 Mark S. Davis
Size of DNA
• 3x109 base pairs• Stretch to 1m in length• Extremely compact • Organized around histones• Around 200 base pairs/histone
![Page 29: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/29.jpg)
© 2003 Mark S. Davis
![Page 30: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/30.jpg)
© 2003 Mark S. Davis
![Page 31: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/31.jpg)
© 2003 Mark S. Davis
RNA
• Single strand
• Different types–tRNA
–mRNA
–rRNA
![Page 32: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/32.jpg)
© 2003 Mark S. Davis
RNA Pairing• A-U
• G-C
• Only about ½ molecules base pair
• Acceptor stem: 3’ end
• Anticodon - opposite
![Page 33: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/33.jpg)
© 2003 Mark S. Davis
Information flow
• Replication: copy DNA in cell division
• Transcription: make RNA (all 3 types) from DNA
• Translation: make polypeptides using rRNA, mRNA, tRNA
![Page 34: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/34.jpg)
© 2003 Mark S. Davis
Replication
• Copy all 46 chromosomes in less than a day (about 8 hrs)
• Error – less than 1 in 10 billion• Always in 5’ 3’ direction and two
strands grow opposite• DNA Polymerase catalyzes
![Page 35: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/35.jpg)
© 2003 Mark S. Davis
![Page 36: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/36.jpg)
© 2003 Mark S. Davis
DNA Polymerase
• Catalyzes pairing of new bases
• “Checks” the accuracy of the pairing and correcting errors
• Parent DNA gives rise to two “daughter” duplexes
![Page 37: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/37.jpg)
© 2003 Mark S. Davis
Practice
• What is the corresponding daughter strand to the parent – 5’-TAGTTCGT-3’
![Page 38: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/38.jpg)
© 2003 Mark S. Davis
Transcription
• Transcription bubble
• RNA Polymerase acts on the template strand only
• There is a start site
• There is a termination site
![Page 39: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/39.jpg)
© 2003 Mark S. Davis
![Page 40: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/40.jpg)
© 2003 Mark S. Davis
![Page 41: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/41.jpg)
© 2003 Mark S. Davis
RNA Polymerase
• No proofreading function
• Error less than 1 in 100,000
• Initial RNA is called primary transcript RNA, ptRNA
• Later modified to the other types
![Page 42: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/42.jpg)
© 2003 Mark S. Davis
What RNA is formed?
• If the DNA sequence is: 5’-GCCTAG-3’
• What is the RNA that is synthesized?
![Page 43: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/43.jpg)
© 2003 Mark S. Davis
Post transcription
• End capping– Adds particular units to the 5’ and 3’ end
• Base modification
• Splicing– Deletes introns– Keeps exons
![Page 44: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/44.jpg)
© 2003 Mark S. Davis
Translation• Protein synthesis
– mRNA, tRNA and rRNA involved– Occurs in cytosol at Ribosomes
• Sequence of bases specifies amino acid sequence– Three bases (codon) = one amino acid
• 64 codons for 20 amino acids– Met, only one codon (START codon)– Stop by three codons
![Page 45: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/45.jpg)
© 2003 Mark S. Davis
![Page 46: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/46.jpg)
© 2003 Mark S. Davis
Translation• Each tRNA carries ONLY ONE aa
• Aminoacyl-tRNA synthetase– Bonds aa to tRNA at 3’ end (ester linkage)
• Peptidyl transferase– Catalyzes transfer of amino acid from tRNA
at ribosome
• Synthesis terminates when STOP codon is reached
![Page 47: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/47.jpg)
© 2003 Mark S. Davis
Posttranslational Processing
• Most lose Met (start residue)
• Folding begins
• Disulfide-bridging
• Quaternary structures assembled
![Page 48: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/48.jpg)
© 2003 Mark S. Davis
Control at every step
• Not every cell expresses every gene
• Specialized
• Repressor proteins– Turn off synthesis of “unneeded” proteins
• Inducer proteins– Turn on synthesis of needed proteins
![Page 49: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/49.jpg)
© 2003 Mark S. Davis
Mutations• Error in base sequence
– Alteration of protein function– Loss of protein function– No noticeable change
• Substitution (point) mutations– One base in place of another
• Frameshift mutations– Base added or deleted
![Page 50: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/50.jpg)
© 2003 Mark S. Davis
Spontaneous Mutations and Mutagens
• Spontaneous mutations– Errors in replication
• Sodium nitrite– In processed meats– Converts cytosine to uracil– Overall danger thought to be low– Reduces occurrence of botulism
![Page 51: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/51.jpg)
© 2003 Mark S. Davis
Spontaneous Mutations and Mutagens
• Benzopyrene– Causes frameshift mutation– Found in car exhaust, tobacco smoke,
burnt meats
• Radiation– Can break bonds and modify bases and
base sequences
![Page 52: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/52.jpg)
© 2003 Mark S. Davis
Silent Mutations
• Base-sequence errors that don’t affect organism– 64 codons for 20 amino acids– Similar amino acids can be substituted– Change may be in unimportant region– Mutation located in intron– Genes have 2 or more copies
![Page 53: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/53.jpg)
© 2003 Mark S. Davis
Mutations
• Somatic cells– Affect individual organism
• Germ cells– Affect all offspring– Genetic (hereditary) diseases
![Page 54: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/54.jpg)
© 2003 Mark S. Davis
Antibiotics
• Chemicals to fight infection
• Block protein synthesis – Stop replication– Attack cell walls
• Must finish whole course
• Bacteria mutate quickly
• Antibiotic resistant bacteria
![Page 55: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/55.jpg)
© 2003 Mark S. Davis
Viruses
• DNA or RNA with protein coat
• No functions outside cell
• Enter cell and “hijack” it
• Each virus attacks only specific cells– TMV– AIDS
![Page 56: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/56.jpg)
© 2003 Mark S. Davis
DNA Viruses
• Enter host cell and nucleus
• Insert themselves into host genome
• Hiding inside cell – hard for immune system to detect
• Can stay indefinitely
![Page 57: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/57.jpg)
© 2003 Mark S. Davis
RNA Viruses
• Enters cell
• Directs synthesis of RNA replicase in cytosol
• Uses machinery of host to make copies of itself
![Page 58: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/58.jpg)
© 2003 Mark S. Davis
Retroviruses
• Special RNA virus
• Enters cell and directs synthesis of viral DNA using reverse transcriptase
• DNA inserts into host genome
• Can hide or remain dormant for long periods of time– HIV
![Page 59: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/59.jpg)
© 2003 Mark S. Davis
Treatment
• Antibiotics don’t work
• Body doesn’t recognize virus once hiding in host cell
• Best method: preemptive vaccines
![Page 60: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/60.jpg)
© 2003 Mark S. Davis
Recombinant DNA Technology
• Began in mid-70s
• Transplanting or altering of DNA
• Benefits– Therapeutic drugs– Improvements to crops and herds– Curing/treating of genetic diseases
![Page 61: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/61.jpg)
© 2003 Mark S. Davis
Production of human insulin
• First application of recombinant DNA technology
• Uses yeast and bacteria as vehicle– Bacteria have genomic DNA and a
plasmid
• Less side effects than cow or pig insulin
![Page 62: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/62.jpg)
© 2003 Mark S. Davis
ProcessIdentify gene encoding wanted protein
1. Isolate this gene from the donor DNA
2. Splice into plasmid (vector DNA)1. Restriction enzymes
3. Recombinant DNA (new plasmid) back into E. coli
1. Chemical shock
2. Heat shock
![Page 63: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/63.jpg)
© 2003 Mark S. Davis
Other techniques• Microinjections
– Direct injection of DNA into nucleus of another cell
– Cloning ~~~ Dolly
• Viral vectors– Altered virus (usually retrovirus)– Carries new DNA to host cell– Research now for cystic fibrosis
![Page 64: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/64.jpg)
© 2003 Mark S. Davis
A Little More About Cloning• Enucleation of cell:
– http://gslc.genetics.utah.edu/units/cloning/whatiscloning/images/enucleation.mpg
• Nuclear Transfer:– http://gslc.genetics.utah.edu/units/cloning/
whatiscloning/images/transfer.mpg
• Cloning “Practice”:– http://gslc.genetics.utah.edu/units/cloning/c
lickandclone/
![Page 65: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/65.jpg)
© 2003 Mark S. Davis
Transgenic Breeding
• Organisms with altered DNA
• Grow faster, larger, etc.
• Resistant to pests– http://www.pbs.org/wgbh/harvest/engineer/t
ransgen.html
• Many already in your supermarket
![Page 66: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/66.jpg)
© 2003 Mark S. Davis
Gene Therapy
• Human Genome Project– Finished with sequence– Now identify genes and proteins
• Insert correct gene for defective one• Modified adenovirus (common cold)
– Aerosol spray inhaled– Injection into bloodstream– Incubation of cells
![Page 67: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/67.jpg)
© 2003 Mark S. Davis
Ethical Considerations• Effects of recombinant DNA?
• Can we test people for diseases?– Alzheimer’s; Huntington’s
• Gene Therapy– Enhance intelligence, strength– Pick eye color
• Who will benefit? Will anyone suffer?
![Page 68: © 2003 Mark S. Davis Chapter 21 Nucleic Acids. © 2003 Mark S. Davis Thanks Mom… Ishihara’s simple testtest X-linked Easy to trace](https://reader036.vdocuments.net/reader036/viewer/2022081603/56649f2c5503460f94c47dce/html5/thumbnails/68.jpg)
© 2003 Mark S. Davis
Internet Sites of Interest
• PBS Site about GMOs– http://www.pbs.org/wgbh/harvest/
• Genetic Science Learning Center– http://www.pbs.org/wgbh/harvest/
• NWABR– http://www.nwabr.org