Hotaru Imai, profile picture
Uploaded byHotaru Imai
PPTX, PDF7,853 views

Microbial genetics microbiology ar

This document provides an overview of microbial genetics. It discusses nucleic acids, DNA replication, transcription, translation, and mutation in bacteria. It also describes several mechanisms of genetic transfer between bacteria, including transformation, transduction, and conjugation. The key topics covered are mutation, genetic exchange processes in bacteria, and the importance of recombination and genetic engineering.

Embed presentation

Downloaded 474 times
Microbial Genetics Ariane Ruby B. Sogo-an MST Biology
Microbial Genetics • Mutation in Bacteria • Genetics Exchange in Bacteria • Recombination and Genetic Engineering
Learning Objectives: 1. Define Mutation. 2. Explain the mechanisms involved in Mutation. 3. Familiarize the processes involved on how Genetic Information are transferred in Bacteria 4. Give the importance of Recombination and Genetic Engineering
Report Outline • Nucleic Acids • Central Dogma • DNA Replication in Bacteria • RNA Synthesis in Bacteria • Protein Synthesis in Bacteria • Changes in the DNA molecule through Mutation • Transfer of Genetic Information in Bacteria
Genetics • Genetics is a study of Heredity. • HOW the information contained in Nucleic Acids is expressed? • HOW this type of molecule is duplicated? • HOW this duplicated molecules are transmitted to progeny?
Nucleic Acids • Nucleic Acids are large organic molecules that are found in ALL cells. • Two Types: • DNA (Deoxyribonucleic Acid) • directs protein production • RNA (Ribonucleic Acid)
Nucleic Acids • Nucleic Acids are large organic molecules that are found in ALL cells. • Two Types: • DNA (Deoxyribonucleic Acid) • directs protein production • RNA (Ribonucleic Acid)
Nucleic Acids • Composition: • Constructed from a string of small molecules called NUCLEOTIDES.
Component of a Nucleotide
Nitrogenous Base
Primary Structure of RNA
Primary Structure of DNA
DNA and RNA
Ribonucleic Acids • RNA are normally single stranded molecules. • Types: (based on their function) • mRNA (Messenger) • tRNA (Transfer) • rRNA (Ribosomal) • Look for specific example
Deoxyribonucleic Acids • Double Stranded, with each strand wrapped around the other in a helical fashion forming a double helix. • Hydrogen bond is specific since A-T (or U in RNA) and G-C ATCCGGC TAGGCCG • Molecule is more stable.
Deoxyribonucleic Acids • Determines the characteristics of an organism and maintains and controls the vital processes of all cells. • How is genetic information expressed? • Transcription (involves formation of RNA molecule using DNA as a template) • Translation (consists of the synthesis of a protein using the genetic information in the RNA)
The Central Dogma
The Central Dogma • Gene • The unit of genetic information or hereditary material contained in DNA molecule. • Sequenced nucleotide in the DNA molecule that codes for RNA molecule and ultimately for the synthesis of a protein.
The Central Dogma • Theory stating that genes guide the synthesis of mRNA and in turn, directs the order in which amino acids are resembled to form protein. • Also postulates that a DNA molecule can direct its own replication by giving rise of two identical DNA molecule.
The Central Dogma • Reverse Transcription • Example: Certain cancer causing viruses (retroviruses) are able to synthesize DNA using RNA as a template.
DNA Replication in Bacteria • Genome – total genetic information in bacteria which consists of circular DNA molecules found within the cell. • Most of the genome is contained in a single bacterial chromosome, although smaller pieces of circular DNA called plasmids may also carry a few important genes such as those coding for resistance to microbial drugs.
DNA Replication in Bacteria • The bacterial chromosomes contains most of the genetic information of bacteria and is attached to the plasma membrane. • Size of the chromosomes varies from species to species. • Example: (per chromosome) • Mycoplasma – fewer than 1 M nucleotide base pairs and a genome can code for 1000 proteins. • E. Coli – 4.5 M nucleotide base pairs that can code for 4500 proteins.
DNA Replication in Bacteria • Both DNA strands are duplicated with each strands functions as a template that specifies the sequence of bases in the newly formed complementary strand. • DNA polymerases • Process nucleotides from the cytoplasm that are complementary to the template and fit them into place. • Parental and New strand = semiconservative.
DNA Replication
DNA Replication • 1. The original double helix molecule. • 2. Helicase enzyme breaks the hydrogen bonds between complementary base pairs. This unzips the double helix at a position called the replication fork. • 3. There is an abundant supply of nucleotides in the nucleus for the formation of the new polynucleotides. • 4. Nucleotides base pair to the bases in the original strands. • 5. DNA polymerase joins together the nucleotides together with strong covalent phosphodiester bonds To form a new complementary polynucleotide strand. • 6. The double strand reforms a double helix under the influence of an enzyme. • 7 Two copies of the DNA molecule form behind the replication fork. These are the new daughter chromosomes.
RNA Synthesis in Bacteria • Transcription • Involves the assembly of nucleotides by an enzyme called RNA polymerase that uses a strand of DNA as its template. • Begins when RNA polymerase binds to the DNA at the promoter site near the gene to be transcribed. • RNA polymerase travels along the length of the DNA strand until it reaches a termination site.
RNA Synthesis in Bacteria • After mRNA is made, it will be used as a guide to make proteins. • Ribosomal RNA, after its made, becomes associated with proteins to form ribosomes. • tRNA are small RNA molecules that are involved in translating the information in the mRNA into proteins.
MUTATION
The Genetic Code • The start codon is AUG. Methionine is the only amino acid specified by just one codon, AUG. • The stop codons are UAA, UAG, and UGA. They encode no amino acid. The ribosome pauses and falls off the mRNA.
Mutation: Base Substitution (Point Mutations) G C Glu (d) Run-on mutation G C (a) Silent mutation
Mutation: Insertions and Deletions Figure 8.17a, d THEBIGCATATETHERAT THEBIGCBATATETHERAT
Summary of Mutation Types Run-on mutation Stop codon lost so protein is extra long (can also produce nonsense and run-ons)
Spontaneous and Induced Mutation • Spontaneous mutation rate = 1 in 109 (a billion) replicated base pairs or 1 in 106 ( a million) replicated genes. Mistakes occur during DNA Replication just before cell division. This is natural error rate of DNA polymerase. • Mutagens increase mistakes to to 10–5 (100 thousand) or 10–3 ( a thousand) per replicated gene
Mutagen • Mutation relevant • Cause DNA damage that can be converted to mutations.
Physical mutagens High-energy ionizing radiation: X-rays and g-rays  strand breaks and base/sugar destruction Nonionizing radiation : UV light pyrimidine dimers Chemical mutagens Base analogs: direct mutagenesis Nitrous acid: deaminates C to produce U Alkylating agents Intercalating agents Lesions-indirect mutagenesis 1 Mutaagenesis
Chemical Mutagens Base pair altering chemicals (base modifiers) deaminators like nitrous acid, nitrosoguanidine, or alkylating agents like cytoxan Base analogues “mimic” certain bases but pair with others - E.g. 5-fluorouracil, cytarabine Acts like a “C” cytarabine cytoxan Nitrous acid
BASE PAIR ALTERING CHEMICALS
Deaminating Agent • *Deaminating agent - Nitrous acid - removes the anime group from Adenine and Cytosine • Nitrous acid is a deaminating agent that converts cytosine to uracil, adenine to hypoxanthine, and guanine to xanthine. The hydrogen-bonding potential of the modified base is altered, resulting in mispairing.
BASE ANALOGS
Alkylating agents • Alkylating agents like EMS/MMS(ethyl/methly methyl sulphonate) add methyl groups to Guanosine . Bulky attachment to the side groups or bases.
Hydroxilating Agents • Addition of OH (Hydroxyl Group) hydroxylamine (HA)
Intercalating Agents • Intercalation agents are compounds that can slide between the nitrogenous bases in a DNA molecule. • This tends to cause a greater likelihood for slippage during replication, resulting in an increase in frameshift mutations. • Example (Sodium Azide)
Chemical FrameshiftMutagens Intercalate into DNA Aflatoxin from Aspergillus fungus growing on corn Benzpyrene in cigarette smoke AT GC TA GC CG AT GC TA GC CG AT GC CG TA GC CG Carboplatin (anti-cancer drug) Daunarubicin (anti-cancer drug) Bleomycin (anti-cancer drug produced by Streptomyces)
Mutation: Ionizing Radiation • Ionizing radiation (X rays, gamma rays, UV light) causes the formation of ions that can react with nucleotides and the deoxyribose-phosphate backbone. • Nucleotide excision repairs mutations
X-rays and Gamma Rays Cause Breaks in DNA
Ionizing Radiation: UV • UV radiation causes thymine dimers, which block replication. • Light-repair separates thymine dimers • Sometimes the “repair job” introduces the wrong nucleotide, leading to a point mutation. Figure 8.20
MDufilho 7/6/11 53 Genetic Transfer • Horizontal Gene Transfer Among Prokaryotes • Horizontal gene transfer • Donor cell contributes part of genome to recipient cell • Three types • Transformation • Transduction • Bacterial conjugation © 2012 Pearson Education Inc.
Bacterial Sexual Processes • Eukaryotes have the processes of meiosis to reduce diploids to haploidy, and fertilization to return the cells to the diploid state. Bacterial sexual processes are not so regular. However, they serve the same aim: to mix the genes from two different organisms together. • The three bacterial sexual processes: • 1. conjugation: direct transfer of DNA from one bacterial cell to another. • 2. transduction: use of a bacteriophage (bacterial virus) to transfer DNA between cells. • 3. transformation: naked DNA is taken up from the environment by bacterial cells.
Transformation • We aren’t going to speak much of this process, except to note that it is very important for recombinant DNA work. The essence of recombinant DNA technology is to remove DNA from cells, manipulate it in the test tube, then put it back into living cells. In most cases this is done by transformation. • In the case of E. coli, cells are made “competent” to be transformed by treatment with calcium ions and heat shock. E. coli cells in this condition readily pick up DNA from their surroundings and incorporate it into their genomes.
Figure 7.33 Transformation in Streptococcus pneumoniae-overview MDufilho 7/6/11 56
Conjugation • Conjugation is the closest analogue in bacteria to eukaryotic sex. • The ability to conjugate is conferred by the F plasmid. A plasmid is a small circle of DNA that replicates independently of the chromosome. Bacterial cells that contain an F plasmid are called “F+”. Bacteria that don’t have an F plasmid are called “F-”. • F+ cells grow special tubes called “sex pilli” from their bodies. When an F+ cell bumps into an F- cell, the sex pilli hold them together, and a copy of the F plasmid is transferred from the F+ to the F-. Now both cells are F+. • Why aren’t all E. coli F+, if it spreads like that? Because the F plasmid can be spontaneously lost.
Figure 7.35 Bacterial conjugation-overview MDufilho 7/6/11 58 F plasmid Origin of transfer Conjugation pilus Chromosome F+ cell F– cell Donor cell attaches to a recipient cell with its pilus. Pilus may draw cells together. One strand of F plasmid DNA transfers to the recipient. F+ cell F+ cell Pilus The recipient synthesizes a complementary strand to become an F+ cell with a pilus; the donor synthesizes a complementary strand, restoring its complete plasmid.
Figure 7.36 Conjugation involving an Hfr cell-overview MDufilho 7/6/11 59 Donor chromosome Pilus F+ cell Hfr cell Pilus F+ cell (Hfr) F plasmid F– recipient Donor DNA Part of F plasmid F plasmid integrates into chromosome by recombination. Cells join via a conjugation pilus. Portion of F plasmid partially moves into recipient cell trailing a strand of donor’s DNA. Conjugation ends with pieces of F plasmid and donor DNA in recipient cell; cells synthesize complementary DNA strands. Donor DNA and recipient DNA recombine, making a recombinant F– cell. Incomplete F plasmid; cell remains F– Recombinant cell (still F–)
Hfr Conjugation • When it exists as a free plasmid, the F plasmid can only transfer itself. This isn’t all that useful for genetics. • However, sometimes the F plasmid can become incorporated into the bacterial chromosome, by a crossover between the F plasmid and the chromosome. The resulting bacterial cell is called an “Hfr”, which stands for “High frequency of recombination”. • Hfr bacteria conjugate just like F+ do, but they drag a copy of the entire chromosome into the F-cell.
Transduction • Transduction is the process of moving bacterial DNA from one cell to another using a bacteriophage. • Bacteriophage or just “phage” are bacterial viruses. They consist of a small piece of DNA inside a protein coat. The protein coat binds to the bacterial surface, then injects the phage DNA. The phage DNA then takes over the cell’s machinery and replicates many virus particles. • Two forms of transduction: • 1. generalized: any piece of the bacterial genome can be transferred • 2. specialized: only specific pieces of the chromosome can be transferred.
Figure 7.34 Transduction-overview MDufilho 7/6/11 62 Bacteriophage Phage injects its DNA. Phage enzymes degrade host DNA. Phage DNA Host bacterial cell (donor cell) Bacterial chromosome Phage with donor DNA (transducing phage) Cell synthesizes new phages that incorporate phage DNA and, mistakenly, some host DNA. Transducing phage Transducing phage injects donor DNA. Recipient host cell Donor DNA is incorporated into recipient’s chromosome by recombination. Transduced cell Inserted DNA
General Phage Life Cycle • 1. Phage attaches to the cell and injects its DNA. • 2. Phage DNA replicates, and is transcribed into RNA, then translated into new phage proteins. • 3. New phage particles are assembled. • 4. Cell is lysed, releasing about 200 new phage particles. • Total time = about 15 minutes.
Why do chromosomes undergo recombination? Deleterious mutations would accumulate in each chromosome Recombination generates genetic diversity
Recombination ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz ABCDEFGhijklmnoPQRSTUVWXYZ abcdefgHIJKLMNOpqrstuvwxyz
Mitotic and meiotic recombination Recombination can occur both during mitosis and meiosis Only meiotic recombination serves the important role of reassorting genes Mitotic recombination may be important for repair of mutations in one of a pair of sister chromatids
Recombination mechanisms Best studied in yeast, bacteria and phage Recombination is mediated by the breakage and joining of DNA strands
Benefits of recombination • Greater variety in offspring: Generates new combinations of alleles • Negative selection can remove deleterious alleles from a population without removing the entire chromosome carrying that allele • Essential to the physical process of meiosis, and hence sexual reproduction • Yeast and Drosophila mutants that block pairing are also defective in recombination, and vice versa!!!!
Genetic Engineering
What is genetic engineering??? Genetic engineering: is the artificial manipulation or alteration of genes. Genetic Engineering involves: • removing a gene (target gene) from one organism • inserting target gene into DNA of another organism • ‘cut and paste’ process.
Some important terms!!! Recombinant DNA: the altered DNA is called recombinant DNA ( recombines after small section of DNA inserted into it). Genetically Modified Organism (GMO): is the organism with the altered DNA.
Genetic Engineering breaks the species barrier!!! • Genetic engineering allows DNA from different species to be joined together. • This often results in combinations of DNA that would never be possible in nature!!! For this reason genetic engineering is not a natural process. • If DNA is transferred from one species to another the organism that receives the DNA is said to be transgenic.
Genetic engineering breaks the species barrier!!! • Examples of cross-species transfer of genes: - a human gene inserted into a bacterium - a human gene inserted into another animal - a bacterial gene placed in a plant
Alternative names for genetic engineering: • Genetic Manipulation • Genetic Modification • Recombinant DNA Technology • Gene Splicing • Gene Cloning
Tools used in genetic engineering!!! • Source of DNA: Target (foreign) DNA – DNA taken from one organism to be placed into the DNA of a second organism. • A cloning vector: Special kind of DNA that can accept foreign DNA and exactly reproduce itself and the foreign DNA e.g. Bacterial plasmid (loop of DNA found in bacteria).
Tools Used in Genetic Engineering Restriction Enzymes: - are special enzymes used to cut the DNA at specific places. - different enzymes cut DNA at specific base sequences known as a recognition site. For example i) One restriction enzyme will always cut DNA at the base sequence: GAATTC. ii) Another restriction enzyme only cuts at the sequence: GATC. - If DNA from two different organisms is cut with the same restriction enzyme the cut ends from both sources will be complementary and can easily stick together.
Restriction enzymes DNA 1 DNA 2
Tools used in Genetic Engineering DNA Ligase: enzyme which acts like a glue sticking foreign DNA to DNA of the cloning vector. • will only work if DNA from the two DNA sources has been cut with the same restriction enzyme i.e. sticky ends of cut DNA will be complementary to each other. Please note diagram illustrating use of restriction enzymes and DNA Ligase in production of recombinant DNA Fig. 19.6 pg. 195
Process of Genetic Engineering Five steps involved in this process: 1. Isolation 2. Cutting 3. Insertion (Ligation) 4. Transformation 5. Expression Note: The following example will explain how a human gene is inserted into a bacterium so that the bacterium can produce human insulin.
Process of Genetic Engineering 1. Isolation: • Removal of human DNA (containing target gene). • Removal of plasmid (bacterial DNA) from bacterium. 2. Cutting: • Both human DNA and plasmid DNA are cut with the same restriction enzyme. • Normally plasmid has only one restriction site while human DNA will have many restriction sites. Please note diagram 19.7 pg. 196
Process of Genetic Engineering Insertion: • means that target gene is placed into the DNA of the plasmid or cloning vector. • cut plasmids are mixed with human DNA sections allowing the cut ends to combine. Transformation Expression
Applications of Genetic Engineering You must know three applications: one involving a plant, one animal and one for a micro-organism. Plants: Weed killer-resistant crops • many types of crop plants have bacterial genes added to them. • these genes make the plants resistant to certain weed killers (herbicides). • this means that the weed killers kill the weeds but do not affect the transgenic plants.
Applications of Genetic Engineering Animals: There is a growing trend to experiment with inserting human genes into the DNA of other mammals. The transgenic animals formed in this way will then produce a human protein and secrete it into their milk or even into their eggs.
Applications of Genetic Engineering Animals: Sheep produce human clotting factor • A human gene has been inserted into the DNA of sheep. • This allows the adult sheep to produce a clotting chemical needed by haemophiliacs to clot their blood – produced in the milk of the sheep. Pharming: is the production of pharmaceuticals by genetically modified animals i.e. sheep, cows, goats etc.
Pharming – using animals to make pharmaceuticals
Applications of Genetic Engineering Micro-organisms: Bacteria make insulin • The human insulin gene has been inserted into a bacterium (E-coli). • This allows the bacterium to produce insulin for use by diabetics.
Ethical Issues in Genetic Engineering GMO’s as a food source: Outlined below are some fears associated with the use of GMO’s as a food source: • Cannibalism: – eating an animal containing a human gene is a form of cannibalism. - feeding GMO’s containing human genes to animals that would later be eaten by humans. • Religious reasons: – eating pig genes that are inserted into sheep would be offensive to Jews and Muslims. • Offensive to vegetarians/vegans: – eating animal genes contained in food plants cause concern.
Ethical Issues in Genetic Engineering Animal Welfare: • There is serious concern that animals will suffer as a result of being genetically modified. • use of growth hormones may cause limb deformation and arthritis as animals grow.
Ethical Issues in Genetic Engineering Genetic Engineering in Humans: The following issues are a cause for concern: • If tests are carried out for genetic diseases, who is entitled to see the results? • Tests on unborn babies – could this lead to abortion if a disease is shown to be present? • Insurance/lending companies – will they insist on genetic tests before they will insure/lend money to a person? • Need for legal controls over the uses to which human cells can be put. • Development and expansion of eugenics.
END OF REPORT

More Related Content

PPTX
Microbial genetics lectures 1, 2, and 3
byMona Othman Albureikan / King Abdulaziz University
 
PPTX
introduction to microbial genetics
byNagaraju Yalavarthi
 
PDF
microbial genetics
byMuhammad Amir Sohail
 
PPT
ppt of Bacterial genetic system
byricha pandey
 
PPTX
Microbial Genetics
byRoshni Mehta
 
PPTX
saccharomyces cerevisiae: genome, Existence in haploid & diploid cell form
bynaren
 
PPTX
Transformation
byAKHTARIMAM3
 
PPTX
Microbial Genetics
byRoshni Mehta
 
Microbial genetics lectures 1, 2, and 3
byMona Othman Albureikan / King Abdulaziz University
 
introduction to microbial genetics
byNagaraju Yalavarthi
 
microbial genetics
byMuhammad Amir Sohail
 
ppt of Bacterial genetic system
byricha pandey
 
Microbial Genetics
byRoshni Mehta
 
saccharomyces cerevisiae: genome, Existence in haploid & diploid cell form
bynaren
 
Transformation
byAKHTARIMAM3
 
Microbial Genetics
byRoshni Mehta
 

What's hot

PPTX
Bacterial genetics. Basics
bySociety for Microbiology and Infection care
 
PPTX
16 s rRNA Gene Sequencing for Bacterial Identification
bySanam Parajuli
 
PPTX
M13 and Mu Virus Structure and Life Cycle
byShashankPatil54
 
PPTX
Bacterial, viral genome organisation
byANU RAJ
 
PPT
Plasmid DNA
byUNIVERSITI MALAYSIA SABAH
 
PPTX
Recombination
byAmit Sahoo
 
PPTX
COSMID PHAGE.pptx
byGengapothiraj
 
PPTX
Sv 40
byYashasvi Kumar Singh
 
PPTX
Enzyme involved in DNA replication
byKAUSHAL SAHU
 
PDF
Bacterial taxonomy
byTamil Silambarasan
 
PDF
Restriction Digestion
byMEENAKSHI DAS
 
PPTX
Rolling circle mechanism ppt
byPraveen Garg
 
PPT
bacterial transduction
byVikas Kumar
 
PPTX
Rolling Circle Replication ppt
bythirupathiSathya
 
PPTX
Sos repair mechanism
byVarnit Chauhan
 
PPTX
Genetic code
byMaitriThakor
 
PPTX
Viriods and prions
byHasnahana Chetia
 
PPTX
Transposon mutagenesis & site directed mutagenesis
byAnuKiruthika
 
PPTX
TRANSPOSABLE ELEMENTS
byAmbica Parthasarathi
 
PPTX
Polycistronic and monocistronic RNA
byAnuKiruthika
 
Bacterial genetics. Basics
bySociety for Microbiology and Infection care
 
16 s rRNA Gene Sequencing for Bacterial Identification
bySanam Parajuli
 
M13 and Mu Virus Structure and Life Cycle
byShashankPatil54
 
Bacterial, viral genome organisation
byANU RAJ
 
Plasmid DNA
byUNIVERSITI MALAYSIA SABAH
 
Recombination
byAmit Sahoo
 
COSMID PHAGE.pptx
byGengapothiraj
 
Sv 40
byYashasvi Kumar Singh
 
Enzyme involved in DNA replication
byKAUSHAL SAHU
 
Bacterial taxonomy
byTamil Silambarasan
 
Restriction Digestion
byMEENAKSHI DAS
 
Rolling circle mechanism ppt
byPraveen Garg
 
bacterial transduction
byVikas Kumar
 
Rolling Circle Replication ppt
bythirupathiSathya
 
Sos repair mechanism
byVarnit Chauhan
 
Genetic code
byMaitriThakor
 
Viriods and prions
byHasnahana Chetia
 
Transposon mutagenesis & site directed mutagenesis
byAnuKiruthika
 
TRANSPOSABLE ELEMENTS
byAmbica Parthasarathi
 
Polycistronic and monocistronic RNA
byAnuKiruthika
 

Similar to Microbial genetics microbiology ar

PPTX
3. Microbial genetics. -2025.pptx
byjeeferevening
 
PPTX
3. Microbiology Microbial genetics-2025.pptx
byjeeferevening
 
PPT
BACTERIAL GENETICS.ppt
bysknjoroge
 
PPT
BACTERIAL GENETICS.ppt
bydawitg2
 
PPTX
4.Bacterial Genetics.pptx
byhabtamu biazin
 
PDF
3.Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
PDF
3. Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
PDF
3. Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
PPTX
Bacterial Genetics Maithili Bharadwaj MDS 1st year (Prosthodontics) (2).pptx
byMaithiliBharadwaj
 
PPTX
Microbiology Bio 127 Microbial Genetics
byShaina Mavreen Villaroza
 
PPT
BACTERIAL GENETICS AND VARIATION IN ALL DOMESTIC ANIMALS
byTesfaye189889
 
PPTX
B.sc. agri i pog unit 1 introduction to genetics
byRai University
 
PPT
Bacterial genetics
byYogita Mistry
 
PPTX
TST 3B assignment2.pptx. DNA: The code of life
byNokwandaKhumalo5
 
PPTX
9. Bacterial Genetics.pptx created December 2024
byoluwasemiloreowoeye
 
PPT
Bacterial Genetics
byMohammad Farouq
 
PPTX
BACTERIAL GENETICS 2021.pptx
byKennyNgowi2
 
PPT
Bacterial Genetics
byMohammad Farouq
 
ZIP
Feb18lecture Post Key
byguest0652564
 
PPTX
Bacterial genetics
byDr Aaron Sarwal
 
3. Microbial genetics. -2025.pptx
byjeeferevening
 
3. Microbiology Microbial genetics-2025.pptx
byjeeferevening
 
BACTERIAL GENETICS.ppt
bysknjoroge
 
BACTERIAL GENETICS.ppt
bydawitg2
 
4.Bacterial Genetics.pptx
byhabtamu biazin
 
3.Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
3. Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
3. Microbiology Microbial genetics-2025.pdf
byjeeferevening
 
Bacterial Genetics Maithili Bharadwaj MDS 1st year (Prosthodontics) (2).pptx
byMaithiliBharadwaj
 
Microbiology Bio 127 Microbial Genetics
byShaina Mavreen Villaroza
 
BACTERIAL GENETICS AND VARIATION IN ALL DOMESTIC ANIMALS
byTesfaye189889
 
B.sc. agri i pog unit 1 introduction to genetics
byRai University
 
Bacterial genetics
byYogita Mistry
 
TST 3B assignment2.pptx. DNA: The code of life
byNokwandaKhumalo5
 
9. Bacterial Genetics.pptx created December 2024
byoluwasemiloreowoeye
 
Bacterial Genetics
byMohammad Farouq
 
BACTERIAL GENETICS 2021.pptx
byKennyNgowi2
 
Bacterial Genetics
byMohammad Farouq
 
Feb18lecture Post Key
byguest0652564
 
Bacterial genetics
byDr Aaron Sarwal
 

More from Hotaru Imai

PPTX
Presentation cellmole
byHotaru Imai
 
PPTX
Second Messenger: cAMP Pathway
byHotaru Imai
 
PPTX
Review of related literature presentation
byHotaru Imai
 
PPTX
How plants colonized the land and evolution
byHotaru Imai
 
PPTX
Multiple inteligence
byHotaru Imai
 
PPTX
Ecological indices report 2222222
byHotaru Imai
 
PPTX
Intermediate level of disturbance hypothesis (idh)
byHotaru Imai
 
PPTX
Mutations ariane
byHotaru Imai
 
PPTX
Elisa
byHotaru Imai
 
PPTX
Historical development of genetics final
byHotaru Imai
 
Presentation cellmole
byHotaru Imai
 
Second Messenger: cAMP Pathway
byHotaru Imai
 
Review of related literature presentation
byHotaru Imai
 
How plants colonized the land and evolution
byHotaru Imai
 
Multiple inteligence
byHotaru Imai
 
Ecological indices report 2222222
byHotaru Imai
 
Intermediate level of disturbance hypothesis (idh)
byHotaru Imai
 
Mutations ariane
byHotaru Imai
 
Elisa
byHotaru Imai
 
Historical development of genetics final
byHotaru Imai
 

Recently uploaded

PDF
Surface Chemistry ( पृष्ठ रसायन ) - Notes PDF - Irfanullah Mehar - JJ Sir Che...
byWorld of Wisdom
 
PPTX
forensic significance of blood and its examination.pptx
byAdrijaKrishna
 
PPTX
Schrodinger wave equation and Physical Significance
bykoreap
 
PDF
How common are oxygenic photosynthesis and large coal deposits on exoplanets?
bySérgio Sacani
 
PPTX
Gene Editing_ Rewriting the Code of Life.pptx
byDrNaderMohamed
 
PDF
Control and Coordination - Short Notes (Prashant Kirad) (1).pdf
byAnu kumari
 
PDF
이영욱 교수님의 물리학회 발표자료 전채_20251120.pdf
bysciencepeople
 
PDF
Bio - Molecules ( जैव अणु ) - PDF Notes - Irfanullah Mehar - JJ Sir Chemistry...
byWorld of Wisdom
 
PPTX
Muscles_of_mastication_Anatomy of neck.
bybushra9akhtar786
 
PPTX
Mass selection is one of the oldest methods of plant breeding Commonly use_20...
bysashanklakineni
 
PDF
Possible identification of the Luna 9 Moon landing site using a novel machine...
bySérgio Sacani
 
PPT
GSE s8p3 distance time graphs for 8th Grade Physical Science
byhfludd
 
PDF
Virtualization 1: Virtual Machine, Hypervisor (Virtual Machine Monitor)
bymrethein98
 
PPTX
Cell Transport Powerpoint.pptx for high school students
byraobondalakunta25
 
PPTX
VIRULENCE FACTOR OF BACTERIA: STRUCTURAL ELEMENT, ENZYMES, TOXINS...
byBIOSPHERE OF KNOWLEDGE
 
PPTX
Digestive system grade 5 Cambridge basic sicence
byVictor Venter
 
PPTX
Grade 9 - Science Fourth Quarter Physics
byModezaPonje
 
PPT
CLASSIFICATION-OF-POISONS.ppt ,
bypreetithakurr888
 
PPTX
OECD 204 (Acute Dermal Toxicity) .pptx
byManjari36
 
PPTX
Cell cycle ( mitosis and meiosis)Msc.pptx
byPallabiBehera9
 
Surface Chemistry ( पृष्ठ रसायन ) - Notes PDF - Irfanullah Mehar - JJ Sir Che...
byWorld of Wisdom
 
forensic significance of blood and its examination.pptx
byAdrijaKrishna
 
Schrodinger wave equation and Physical Significance
bykoreap
 
How common are oxygenic photosynthesis and large coal deposits on exoplanets?
bySérgio Sacani
 
Gene Editing_ Rewriting the Code of Life.pptx
byDrNaderMohamed
 
Control and Coordination - Short Notes (Prashant Kirad) (1).pdf
byAnu kumari
 
이영욱 교수님의 물리학회 발표자료 전채_20251120.pdf
bysciencepeople
 
Bio - Molecules ( जैव अणु ) - PDF Notes - Irfanullah Mehar - JJ Sir Chemistry...
byWorld of Wisdom
 
Muscles_of_mastication_Anatomy of neck.
bybushra9akhtar786
 
Mass selection is one of the oldest methods of plant breeding Commonly use_20...
bysashanklakineni
 
Possible identification of the Luna 9 Moon landing site using a novel machine...
bySérgio Sacani
 
GSE s8p3 distance time graphs for 8th Grade Physical Science
byhfludd
 
Virtualization 1: Virtual Machine, Hypervisor (Virtual Machine Monitor)
bymrethein98
 
Cell Transport Powerpoint.pptx for high school students
byraobondalakunta25
 
VIRULENCE FACTOR OF BACTERIA: STRUCTURAL ELEMENT, ENZYMES, TOXINS...
byBIOSPHERE OF KNOWLEDGE
 
Digestive system grade 5 Cambridge basic sicence
byVictor Venter
 
Grade 9 - Science Fourth Quarter Physics
byModezaPonje
 
CLASSIFICATION-OF-POISONS.ppt ,
bypreetithakurr888
 
OECD 204 (Acute Dermal Toxicity) .pptx
byManjari36
 
Cell cycle ( mitosis and meiosis)Msc.pptx
byPallabiBehera9
 

Microbial genetics microbiology ar

  • 1.
    Microbial Genetics ArianeRuby B. Sogo-an MST Biology
  • 2.
    Microbial Genetics •Mutation in Bacteria • Genetics Exchange in Bacteria • Recombination and Genetic Engineering
  • 3.
    Learning Objectives: 1.Define Mutation. 2. Explain the mechanisms involved in Mutation. 3. Familiarize the processes involved on how Genetic Information are transferred in Bacteria 4. Give the importance of Recombination and Genetic Engineering
  • 4.
    Report Outline •Nucleic Acids • Central Dogma • DNA Replication in Bacteria • RNA Synthesis in Bacteria • Protein Synthesis in Bacteria • Changes in the DNA molecule through Mutation • Transfer of Genetic Information in Bacteria
  • 5.
    Genetics • Geneticsis a study of Heredity. • HOW the information contained in Nucleic Acids is expressed? • HOW this type of molecule is duplicated? • HOW this duplicated molecules are transmitted to progeny?
  • 6.
    Nucleic Acids •Nucleic Acids are large organic molecules that are found in ALL cells. • Two Types: • DNA (Deoxyribonucleic Acid) • directs protein production • RNA (Ribonucleic Acid)
  • 7.
    Nucleic Acids •Nucleic Acids are large organic molecules that are found in ALL cells. • Two Types: • DNA (Deoxyribonucleic Acid) • directs protein production • RNA (Ribonucleic Acid)
  • 8.
    Nucleic Acids •Composition: • Constructed from a string of small molecules called NUCLEOTIDES.
  • 9.
    Component of aNucleotide
  • 10.
  • 11.
  • 12.
  • 14.
  • 15.
    Ribonucleic Acids •RNA are normally single stranded molecules. • Types: (based on their function) • mRNA (Messenger) • tRNA (Transfer) • rRNA (Ribosomal) • Look for specific example
  • 17.
    Deoxyribonucleic Acids •Double Stranded, with each strand wrapped around the other in a helical fashion forming a double helix. • Hydrogen bond is specific since A-T (or U in RNA) and G-C ATCCGGC TAGGCCG • Molecule is more stable.
  • 18.
    Deoxyribonucleic Acids •Determines the characteristics of an organism and maintains and controls the vital processes of all cells. • How is genetic information expressed? • Transcription (involves formation of RNA molecule using DNA as a template) • Translation (consists of the synthesis of a protein using the genetic information in the RNA)
  • 19.
  • 21.
    The Central Dogma • Gene • The unit of genetic information or hereditary material contained in DNA molecule. • Sequenced nucleotide in the DNA molecule that codes for RNA molecule and ultimately for the synthesis of a protein.
  • 22.
    The Central Dogma • Theory stating that genes guide the synthesis of mRNA and in turn, directs the order in which amino acids are resembled to form protein. • Also postulates that a DNA molecule can direct its own replication by giving rise of two identical DNA molecule.
  • 23.
    The Central Dogma • Reverse Transcription • Example: Certain cancer causing viruses (retroviruses) are able to synthesize DNA using RNA as a template.
  • 24.
    DNA Replication inBacteria • Genome – total genetic information in bacteria which consists of circular DNA molecules found within the cell. • Most of the genome is contained in a single bacterial chromosome, although smaller pieces of circular DNA called plasmids may also carry a few important genes such as those coding for resistance to microbial drugs.
  • 25.
    DNA Replication inBacteria • The bacterial chromosomes contains most of the genetic information of bacteria and is attached to the plasma membrane. • Size of the chromosomes varies from species to species. • Example: (per chromosome) • Mycoplasma – fewer than 1 M nucleotide base pairs and a genome can code for 1000 proteins. • E. Coli – 4.5 M nucleotide base pairs that can code for 4500 proteins.
  • 26.
    DNA Replication inBacteria • Both DNA strands are duplicated with each strands functions as a template that specifies the sequence of bases in the newly formed complementary strand. • DNA polymerases • Process nucleotides from the cytoplasm that are complementary to the template and fit them into place. • Parental and New strand = semiconservative.
  • 27.
  • 28.
    DNA Replication •1. The original double helix molecule. • 2. Helicase enzyme breaks the hydrogen bonds between complementary base pairs. This unzips the double helix at a position called the replication fork. • 3. There is an abundant supply of nucleotides in the nucleus for the formation of the new polynucleotides. • 4. Nucleotides base pair to the bases in the original strands. • 5. DNA polymerase joins together the nucleotides together with strong covalent phosphodiester bonds To form a new complementary polynucleotide strand. • 6. The double strand reforms a double helix under the influence of an enzyme. • 7 Two copies of the DNA molecule form behind the replication fork. These are the new daughter chromosomes.
  • 29.
    RNA Synthesis inBacteria • Transcription • Involves the assembly of nucleotides by an enzyme called RNA polymerase that uses a strand of DNA as its template. • Begins when RNA polymerase binds to the DNA at the promoter site near the gene to be transcribed. • RNA polymerase travels along the length of the DNA strand until it reaches a termination site.
  • 31.
    RNA Synthesis inBacteria • After mRNA is made, it will be used as a guide to make proteins. • Ribosomal RNA, after its made, becomes associated with proteins to form ribosomes. • tRNA are small RNA molecules that are involved in translating the information in the mRNA into proteins.
  • 32.
  • 34.
    The Genetic Code • The start codon is AUG. Methionine is the only amino acid specified by just one codon, AUG. • The stop codons are UAA, UAG, and UGA. They encode no amino acid. The ribosome pauses and falls off the mRNA.
  • 35.
    Mutation: Base Substitution(Point Mutations) G C Glu (d) Run-on mutation G C (a) Silent mutation
  • 37.
    Mutation: Insertions andDeletions Figure 8.17a, d THEBIGCATATETHERAT THEBIGCBATATETHERAT
  • 38.
    Summary of MutationTypes Run-on mutation Stop codon lost so protein is extra long (can also produce nonsense and run-ons)
  • 39.
    Spontaneous and InducedMutation • Spontaneous mutation rate = 1 in 109 (a billion) replicated base pairs or 1 in 106 ( a million) replicated genes. Mistakes occur during DNA Replication just before cell division. This is natural error rate of DNA polymerase. • Mutagens increase mistakes to to 10–5 (100 thousand) or 10–3 ( a thousand) per replicated gene
  • 40.
    Mutagen • Mutationrelevant • Cause DNA damage that can be converted to mutations.
  • 41.
    Physical mutagens High-energyionizing radiation: X-rays and g-rays  strand breaks and base/sugar destruction Nonionizing radiation : UV light pyrimidine dimers Chemical mutagens Base analogs: direct mutagenesis Nitrous acid: deaminates C to produce U Alkylating agents Intercalating agents Lesions-indirect mutagenesis 1 Mutaagenesis
  • 42.
    Chemical Mutagens Basepair altering chemicals (base modifiers) deaminators like nitrous acid, nitrosoguanidine, or alkylating agents like cytoxan Base analogues “mimic” certain bases but pair with others - E.g. 5-fluorouracil, cytarabine Acts like a “C” cytarabine cytoxan Nitrous acid
  • 43.
  • 44.
    Deaminating Agent •*Deaminating agent - Nitrous acid - removes the anime group from Adenine and Cytosine • Nitrous acid is a deaminating agent that converts cytosine to uracil, adenine to hypoxanthine, and guanine to xanthine. The hydrogen-bonding potential of the modified base is altered, resulting in mispairing.
  • 45.
  • 46.
    Alkylating agents •Alkylating agents like EMS/MMS(ethyl/methly methyl sulphonate) add methyl groups to Guanosine . Bulky attachment to the side groups or bases.
  • 47.
    Hydroxilating Agents •Addition of OH (Hydroxyl Group) hydroxylamine (HA)
  • 48.
    Intercalating Agents •Intercalation agents are compounds that can slide between the nitrogenous bases in a DNA molecule. • This tends to cause a greater likelihood for slippage during replication, resulting in an increase in frameshift mutations. • Example (Sodium Azide)
  • 49.
    Chemical FrameshiftMutagens Intercalateinto DNA Aflatoxin from Aspergillus fungus growing on corn Benzpyrene in cigarette smoke AT GC TA GC CG AT GC TA GC CG AT GC CG TA GC CG Carboplatin (anti-cancer drug) Daunarubicin (anti-cancer drug) Bleomycin (anti-cancer drug produced by Streptomyces)
  • 50.
    Mutation: Ionizing Radiation • Ionizing radiation (X rays, gamma rays, UV light) causes the formation of ions that can react with nucleotides and the deoxyribose-phosphate backbone. • Nucleotide excision repairs mutations
  • 51.
    X-rays and GammaRays Cause Breaks in DNA
  • 52.
    Ionizing Radiation: UV • UV radiation causes thymine dimers, which block replication. • Light-repair separates thymine dimers • Sometimes the “repair job” introduces the wrong nucleotide, leading to a point mutation. Figure 8.20
  • 53.
    MDufilho 7/6/11 53 Genetic Transfer • Horizontal Gene Transfer Among Prokaryotes • Horizontal gene transfer • Donor cell contributes part of genome to recipient cell • Three types • Transformation • Transduction • Bacterial conjugation © 2012 Pearson Education Inc.
  • 54.
    Bacterial Sexual Processes • Eukaryotes have the processes of meiosis to reduce diploids to haploidy, and fertilization to return the cells to the diploid state. Bacterial sexual processes are not so regular. However, they serve the same aim: to mix the genes from two different organisms together. • The three bacterial sexual processes: • 1. conjugation: direct transfer of DNA from one bacterial cell to another. • 2. transduction: use of a bacteriophage (bacterial virus) to transfer DNA between cells. • 3. transformation: naked DNA is taken up from the environment by bacterial cells.
  • 55.
    Transformation • Wearen’t going to speak much of this process, except to note that it is very important for recombinant DNA work. The essence of recombinant DNA technology is to remove DNA from cells, manipulate it in the test tube, then put it back into living cells. In most cases this is done by transformation. • In the case of E. coli, cells are made “competent” to be transformed by treatment with calcium ions and heat shock. E. coli cells in this condition readily pick up DNA from their surroundings and incorporate it into their genomes.
  • 56.
    Figure 7.33 Transformationin Streptococcus pneumoniae-overview MDufilho 7/6/11 56
  • 57.
    Conjugation • Conjugationis the closest analogue in bacteria to eukaryotic sex. • The ability to conjugate is conferred by the F plasmid. A plasmid is a small circle of DNA that replicates independently of the chromosome. Bacterial cells that contain an F plasmid are called “F+”. Bacteria that don’t have an F plasmid are called “F-”. • F+ cells grow special tubes called “sex pilli” from their bodies. When an F+ cell bumps into an F- cell, the sex pilli hold them together, and a copy of the F plasmid is transferred from the F+ to the F-. Now both cells are F+. • Why aren’t all E. coli F+, if it spreads like that? Because the F plasmid can be spontaneously lost.
  • 58.
    Figure 7.35 Bacterialconjugation-overview MDufilho 7/6/11 58 F plasmid Origin of transfer Conjugation pilus Chromosome F+ cell F– cell Donor cell attaches to a recipient cell with its pilus. Pilus may draw cells together. One strand of F plasmid DNA transfers to the recipient. F+ cell F+ cell Pilus The recipient synthesizes a complementary strand to become an F+ cell with a pilus; the donor synthesizes a complementary strand, restoring its complete plasmid.
  • 59.
    Figure 7.36 Conjugationinvolving an Hfr cell-overview MDufilho 7/6/11 59 Donor chromosome Pilus F+ cell Hfr cell Pilus F+ cell (Hfr) F plasmid F– recipient Donor DNA Part of F plasmid F plasmid integrates into chromosome by recombination. Cells join via a conjugation pilus. Portion of F plasmid partially moves into recipient cell trailing a strand of donor’s DNA. Conjugation ends with pieces of F plasmid and donor DNA in recipient cell; cells synthesize complementary DNA strands. Donor DNA and recipient DNA recombine, making a recombinant F– cell. Incomplete F plasmid; cell remains F– Recombinant cell (still F–)
  • 60.
    Hfr Conjugation •When it exists as a free plasmid, the F plasmid can only transfer itself. This isn’t all that useful for genetics. • However, sometimes the F plasmid can become incorporated into the bacterial chromosome, by a crossover between the F plasmid and the chromosome. The resulting bacterial cell is called an “Hfr”, which stands for “High frequency of recombination”. • Hfr bacteria conjugate just like F+ do, but they drag a copy of the entire chromosome into the F-cell.
  • 61.
    Transduction • Transductionis the process of moving bacterial DNA from one cell to another using a bacteriophage. • Bacteriophage or just “phage” are bacterial viruses. They consist of a small piece of DNA inside a protein coat. The protein coat binds to the bacterial surface, then injects the phage DNA. The phage DNA then takes over the cell’s machinery and replicates many virus particles. • Two forms of transduction: • 1. generalized: any piece of the bacterial genome can be transferred • 2. specialized: only specific pieces of the chromosome can be transferred.
  • 62.
    Figure 7.34 Transduction-overview MDufilho 7/6/11 62 Bacteriophage Phage injects its DNA. Phage enzymes degrade host DNA. Phage DNA Host bacterial cell (donor cell) Bacterial chromosome Phage with donor DNA (transducing phage) Cell synthesizes new phages that incorporate phage DNA and, mistakenly, some host DNA. Transducing phage Transducing phage injects donor DNA. Recipient host cell Donor DNA is incorporated into recipient’s chromosome by recombination. Transduced cell Inserted DNA
  • 63.
    General Phage LifeCycle • 1. Phage attaches to the cell and injects its DNA. • 2. Phage DNA replicates, and is transcribed into RNA, then translated into new phage proteins. • 3. New phage particles are assembled. • 4. Cell is lysed, releasing about 200 new phage particles. • Total time = about 15 minutes.
  • 64.
    Why do chromosomesundergo recombination? Deleterious mutations would accumulate in each chromosome Recombination generates genetic diversity
  • 65.
    Recombination ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz ABCDEFGhijklmnoPQRSTUVWXYZ abcdefgHIJKLMNOpqrstuvwxyz
  • 66.
    Mitotic and meioticrecombination Recombination can occur both during mitosis and meiosis Only meiotic recombination serves the important role of reassorting genes Mitotic recombination may be important for repair of mutations in one of a pair of sister chromatids
  • 67.
    Recombination mechanisms Beststudied in yeast, bacteria and phage Recombination is mediated by the breakage and joining of DNA strands
  • 68.
    Benefits of recombination • Greater variety in offspring: Generates new combinations of alleles • Negative selection can remove deleterious alleles from a population without removing the entire chromosome carrying that allele • Essential to the physical process of meiosis, and hence sexual reproduction • Yeast and Drosophila mutants that block pairing are also defective in recombination, and vice versa!!!!
  • 69.
  • 70.
    What is geneticengineering??? Genetic engineering: is the artificial manipulation or alteration of genes. Genetic Engineering involves: • removing a gene (target gene) from one organism • inserting target gene into DNA of another organism • ‘cut and paste’ process.
  • 71.
    Some important terms!!! Recombinant DNA: the altered DNA is called recombinant DNA ( recombines after small section of DNA inserted into it). Genetically Modified Organism (GMO): is the organism with the altered DNA.
  • 72.
    Genetic Engineering breaksthe species barrier!!! • Genetic engineering allows DNA from different species to be joined together. • This often results in combinations of DNA that would never be possible in nature!!! For this reason genetic engineering is not a natural process. • If DNA is transferred from one species to another the organism that receives the DNA is said to be transgenic.
  • 73.
    Genetic engineering breaksthe species barrier!!! • Examples of cross-species transfer of genes: - a human gene inserted into a bacterium - a human gene inserted into another animal - a bacterial gene placed in a plant
  • 74.
    Alternative names forgenetic engineering: • Genetic Manipulation • Genetic Modification • Recombinant DNA Technology • Gene Splicing • Gene Cloning
  • 75.
    Tools used ingenetic engineering!!! • Source of DNA: Target (foreign) DNA – DNA taken from one organism to be placed into the DNA of a second organism. • A cloning vector: Special kind of DNA that can accept foreign DNA and exactly reproduce itself and the foreign DNA e.g. Bacterial plasmid (loop of DNA found in bacteria).
  • 76.
    Tools Used inGenetic Engineering Restriction Enzymes: - are special enzymes used to cut the DNA at specific places. - different enzymes cut DNA at specific base sequences known as a recognition site. For example i) One restriction enzyme will always cut DNA at the base sequence: GAATTC. ii) Another restriction enzyme only cuts at the sequence: GATC. - If DNA from two different organisms is cut with the same restriction enzyme the cut ends from both sources will be complementary and can easily stick together.
  • 77.
  • 78.
    Tools used inGenetic Engineering DNA Ligase: enzyme which acts like a glue sticking foreign DNA to DNA of the cloning vector. • will only work if DNA from the two DNA sources has been cut with the same restriction enzyme i.e. sticky ends of cut DNA will be complementary to each other. Please note diagram illustrating use of restriction enzymes and DNA Ligase in production of recombinant DNA Fig. 19.6 pg. 195
  • 79.
    Process of GeneticEngineering Five steps involved in this process: 1. Isolation 2. Cutting 3. Insertion (Ligation) 4. Transformation 5. Expression Note: The following example will explain how a human gene is inserted into a bacterium so that the bacterium can produce human insulin.
  • 80.
    Process of GeneticEngineering 1. Isolation: • Removal of human DNA (containing target gene). • Removal of plasmid (bacterial DNA) from bacterium. 2. Cutting: • Both human DNA and plasmid DNA are cut with the same restriction enzyme. • Normally plasmid has only one restriction site while human DNA will have many restriction sites. Please note diagram 19.7 pg. 196
  • 81.
    Process of GeneticEngineering Insertion: • means that target gene is placed into the DNA of the plasmid or cloning vector. • cut plasmids are mixed with human DNA sections allowing the cut ends to combine. Transformation Expression
  • 82.
    Applications of GeneticEngineering You must know three applications: one involving a plant, one animal and one for a micro-organism. Plants: Weed killer-resistant crops • many types of crop plants have bacterial genes added to them. • these genes make the plants resistant to certain weed killers (herbicides). • this means that the weed killers kill the weeds but do not affect the transgenic plants.
  • 83.
    Applications of GeneticEngineering Animals: There is a growing trend to experiment with inserting human genes into the DNA of other mammals. The transgenic animals formed in this way will then produce a human protein and secrete it into their milk or even into their eggs.
  • 84.
    Applications of GeneticEngineering Animals: Sheep produce human clotting factor • A human gene has been inserted into the DNA of sheep. • This allows the adult sheep to produce a clotting chemical needed by haemophiliacs to clot their blood – produced in the milk of the sheep. Pharming: is the production of pharmaceuticals by genetically modified animals i.e. sheep, cows, goats etc.
  • 85.
    Pharming – usinganimals to make pharmaceuticals
  • 86.
    Applications of GeneticEngineering Micro-organisms: Bacteria make insulin • The human insulin gene has been inserted into a bacterium (E-coli). • This allows the bacterium to produce insulin for use by diabetics.
  • 87.
    Ethical Issues inGenetic Engineering GMO’s as a food source: Outlined below are some fears associated with the use of GMO’s as a food source: • Cannibalism: – eating an animal containing a human gene is a form of cannibalism. - feeding GMO’s containing human genes to animals that would later be eaten by humans. • Religious reasons: – eating pig genes that are inserted into sheep would be offensive to Jews and Muslims. • Offensive to vegetarians/vegans: – eating animal genes contained in food plants cause concern.
  • 88.
    Ethical Issues inGenetic Engineering Animal Welfare: • There is serious concern that animals will suffer as a result of being genetically modified. • use of growth hormones may cause limb deformation and arthritis as animals grow.
  • 89.
    Ethical Issues inGenetic Engineering Genetic Engineering in Humans: The following issues are a cause for concern: • If tests are carried out for genetic diseases, who is entitled to see the results? • Tests on unborn babies – could this lead to abortion if a disease is shown to be present? • Insurance/lending companies – will they insist on genetic tests before they will insure/lend money to a person? • Need for legal controls over the uses to which human cells can be put. • Development and expansion of eugenics.
  • 90.