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Coxiella burnetti Bartonella henselae Moraxella catarrhalis Bifidobacterium breve Anaplasma phagocytophilum Gram Stain negative negative negative positive negative (no LPS) Motile nonmotile Twitching pili nonmotile nonmotile non-motile Pathogenic Obligate intracellular Facultative intracellular Opportunistic pathogen Nonpathogenic- fermenter Obligate intracellular Causes Q fever: from animals to human and causes flu-like symptoms but can be chronic Cat Scratch Disease: from cats to humans, no symptoms in cats, but humans have swollen lymph nodes, fatigue, fever Major cause of Nosocomial infection and Bronchopulmonary Ferments lactic acid and acetic acid; no antibiotic resistance and great probiotic Tick-borne disease, granulocytic ehrlichiosis, anaplasmosis… attacks granulocytes (white blood cells)... fever, headache Morphology Coccobacillus Rod shaped Diplococci Forked rods Pleomorphic cocci Temp. mesophile mesophile mesophile mesophile mesophile Type of Anaerobic Facultative anaerobe aerobic Aerobic Obligate anaerobe Facultative Anaerobe Other notes Acidophile; highly infectious with low infection dose, can withstand high heat and desiccation ( forms but not spore forming) Reservoir cat, dangerous to HIV populations, slow grower/fastidious, replicates inside and outside the host cell Found in human flora mucosal epithelial cells of the upper respiratory tract, 15-20% of acute otitis media, fastidious grower, biofilm former, resistant to antibiotic Unique metabolic pathways which allows them to catabolize carbohydrates and oligosaccharides in breast milk; symbiotic with humans--first colonizers in infants “Thing without plasma/ attached to phagocytes”... Ixode tickets (midwest and northeast) with a reservoir of white-footed mice and white tailed deer… emerging disease… smaller than more bacteria Guest Lecture- Food Safety ● Food Safety hazard: unfit for human consumption ○ Biological: bacteria, viruses, molds, parasites ○ Physical: glass, screws, drawing pins, and stones ○ Chemical: insecticides, cleaning agents ○ Allergenic: nuts, peanuts, shellfish, gluten, diary, etc
● Foodborne illness/disease: a disease usually infectious or toxic in nature caused by agents that enter our body through ingestion of food ○ Foodborne illness: live pathogen in food (shown to have longer period between time of infection/ingestion to symptoms) ○ Foodborne intoxication: toxins in food (shorter period between ingestion and showing symptoms) ● 1 in 6 Americans experience illness from foodborne illness each year, and out of that 3,000 people die ● Had led to food recall, reduced customer demand, lawsuit, and fines ○ On the positive, it has improved safety process and increased marketing efforts ○ Individual financial implications: lost job, medical cost, and/or physical disability ● Produce (berries, leafy greens), eggs, meats are some of the most dangerous foods; however, nothing is safe ● Symptoms of food poisoning ○ Diarrhea, abdominal cramps, nausea, fever, vomiting ○ Can be severe or fatal if old, immunocompromised, and on certain medications ○ Cause chronic illnesses (arthritis, kidney damage, miscarriages, allergic reactions) ● Leading causes of foodborne illness ○ Norovirus ○ Salmonella (chickens and produce) ○ Clostridium perfringens ● Leading cause of death from foodborne illness ○ Salmonella ○ Toxoplasma gondii ○ Listeria monocytogenes ● Where is food contaminated ○ Farm/growing at preharvest (through water, weather, insecticides) ○ Production at postharvest (human intervention, cleaning process) ○ Final processing at handling before eaten and sold (contamination of cooked from raw, double dipping, and five second rule) ● Foodborne disease is preventable through better sanitation, public surveillance and outbreak investigation, food processing improvement, and vaccines ● FDA, EPA, USDA, and CDC all watch over foodborne illness and prevention ● When you reduce the chance of contamination, you reduce the chance of illness ● At the grocery store, shop from room temperature to cold/freezing, but at home put away the cold products to the room temperature ● When cooking, always separate raw foods/materials from cooked; then make sure it is thoroughly cooked ● For produce, always clean well and separate from the contaimates/spoiled, then properly throw away
● Rotavirus is responsible for 20-25% of all diarrheal diseases worldwide ● Norovirus is responsible for 58% of foodborne illnesses ● Campylobacter jejuni is responsible for 400 million cases of diarrhea worldwide ● Lactobacilli and Bifidobacteria were shown to enhance colonization resistance when infected ● Probiotic action is nonspecific and nondiscriminatory or ineffective in certain host ● Recombinant probiotics have been generated for mucosal delivery for therapeutic and prophylactic molecules ● The major advantages of probiotics as delivery system are: ○ Ability to colonize musical surface ○ Tolerance to gastric acid and bile salts enabling survival and transit through the gastrointestinal tract ○ Sustained colonization and prolonged protection against pathogen ● Oral recombinant probiotic offer several advantages: ○ Direct delivery of active molecule to the mucosal surface without the need for bio-separation of the active molecules ○ Increase shelf-life and stability ○ Low delivery and cost ○ Ease of technology transfer following prototype development ● In order to create effective recombinant probiotics, certain physiologic attributes are essential: ○ Tolerance to stressors encountered during product manufacturing and storage ○ Strong mucosal colonization ○ Expression of target antigen under the gastrointestinal environment ○ Potent antipathogenic action ● Probiotics encounter stress during man, storage, and passage through GIT (temperature, acidity, salts and water activity) ● Accumulation of compatible solutes help stabilize protein function at low temperatures ● Receptor mimicry system and toxin neutralization ○ Created a competitive environment for toxins to bind to the host cells ● Prevention of colonization ○ Cloning and expression of adhesins, toxins or secretory system of pathogen may serve as potential targets for development of therapeutics to prevent infection ○ Enhance probiotics adhesion to mucosal surface using gene products of target population to create a competitive environment for pathogen colonization ● Regulation of virulence gene expression ○ Pathogenic bacteria have the ability to control the expression of the virulence genes by sensing signals (quorum sensing) from their own species ○ Interruption of quorum sensing pathways may serve as a viable option for disease prevention
● Production of Antimicrobial factors ○ Some probiotics produce several antimicrobial compounds and peptides as a defense mechanism against pathogens ○ Engineer probiotics to detect pathogen signals for timed production of antimicrobials ○ Also able to control pathogen transmission by insects (ie insect synbiotics) ● Immunocompromised and cytoprotection ○ Develop strains that can provide protection on mucosal membrane ○ Easier to combat infection by blocking it rather than by eliminating it ○ Recombinant probiotic bacteria would be ideal because of their ability to bind to mucosal surfaces, promoting effective contact between the antigen and the immune system ○ Enable continued production of the immunogenic molecule to stimulate humoral and cellular immune responses ○ Deliver vaccines to mucosal surfaces ○ Several probiotic strain have been engineered to expressed cytokines and other anti-inflammatory molecules to help suppress intestinal inflammation and provide cytoprotection ● Bacteria need to been screened for potential pathogenicity and virulence traits ● Also screened genetically for use as probiotic ● Do not carry any transferable antibiotic resistance genes, which can serve as genetic reservoirs for other pathogenic bacteria ● Preventing its accumulation in the environment and preventing lateral dissemination of the genetic material to other bacteria ● Active containment involves the conditional production of a bacterial toxin through tightly regulated gene expression that is controlled by an environmental cue ● Passive containment results in growth dependent on the implementation of an auxotrophy or gene defeat, by supplementing another gene or essential metabolite LECTURE NOTES Chapter 6 1.) Understand the importance for chemoorganohetrotrophic funneling substrates towards the same metabolic pathways
- Saves energy, doesn’t waste 2.) What ways can cells use to get energy?
- ATP and GTP
- Substrate level phosphorylation, photophosphorylation
- Oxidative phosphorylation 3.) Understand amphibolic pathways
- Functions both as catabolic and anabolic pathways
- Generates ATP
- Oxidative phosphorylation: electrons are transferred from the electron donors to a series of electron acceptors in a series of redox reactions ending in oxygen
- Generates NADH 7.) What happens during transition/prep step (pyruvate dehydrogenase)
- Pyruvate is transformed into acetyl-CoA, using NAD+ to NADH 8.) TCA cycle: where it occurs in both eukaryotes and prokaryotes, how many NADH, FADH 2 , CO 2 , and GTP are generated. Point of regulation (isocitrate dehydrogenase)
- In eukaryotes, occurs in mitochondria
- In prokaryotes, occurs in cytoplasm
- Creates 2 CO2, 3 NADH, 1 FADH and 1 GTP
- But two pyruvates (and thus two acetyl CoA) are created, so for one glucose the reaction is doubled
- Doesn’t create a lot of ATP, but creates a lot of electron carriers that are important for ETC
- Points of regulation:
- Isocitrate dehydrogenase (between isocitrate and alpha-ketoglutarate)
- Turns on cycle due to NAD+
- Alpha-ketoglutarate dehydrogenase (between alpha-ketoglutarate and succinyl-CoA)
- Turns off cycle due to excess NADH 9.) Concept of redox potential and how the redox potential of a conjugate pair (either – or +) determine how electrons will flow
- Redox potential: the tendency of molecule to acquire electrons
- Electrons flow from carriers with more negative reduction potential to carriers with more positive reduction potential 10.) General concept of how the ETC works and how movement of electrons leads to generation of PMF and in turn ATP generation
- Electron transport chain
- The most ATP is made when NADH and FADH2 are oxidized the ETC
- Picks up electrons and gives them a ride to the four complexes
- Electrons flows from carriers to complexes in the plasma membrane it releases a little energy to be able to pump protons across the membrane
- NADH donates into complex one and FADH2 donates into complex two
- The terminal acceptor is O
- Complex I, II, IV pump protons across
- CoQ: takes electrons from complex I and complex II for complex III
- CytC: pulls electrons in complex IIIand sends them to complex IV
- The more complex the better the gradient
- The difference in reduction potentials of electron carriers, NADH, and O2 allows electrons to follow 11.) ETC: oxidative phosphorylation, why so much more ATP generated from ETC than glycolysis and TCA – Chemiosmotic hypothesis
- More ATP generate when the most potential energy is stored
- Chemiosmotic hypothesis: the energy from the flow of protons can be used to drive the enzyme ATP synthase 12.) Differences in bacterial ETCs compared to eukaryotic and archaea: how ATP yield compares and why
- ETC in eukaryotes: very conserved, occurs within the inner mitochondrial membrane and connected by coenzyme Q and cytochrome C
- ETC in archaea/bacteria: located in the plasma membrane; differences in electron carrier, maybe branched or shorter, may have a lower phosphorus to oxygen ratio (releases less energy) 13.) ATP synthase how it works to generate ATP
- Diffusion of protons back across membrane drives formation of ATP
- Enzymes that uses PMF (proton motive force) down gradient to catalyze ATP synthesis
- Functions like a rotary engine with conformational changes
- F0: made from a and c subunit, which forms the channel that the protons move down
- The b subunit spans F0 and F1 as it anchors those two together
- F1: alpha and beta subunit can undergo a conformational change that allows phosphorus to bind to ADP) and gamma spindle induces spin for that change 14.) ATP Yield in Eukaryotic Cells
- 2 ATP from glycolysis
- 2 ATP from TCA
- 28/34 ATP From oxidative phosphorylation
- Total of 32 to 38 ATP 15.) Anaerobic respiration compared to aerobic: differences, why less ATP generated
- Uses electron carriers other than oxygen
- The reduction potential of the electron acceptors is less positive than the electron potential of O 16.) Fermentation: importance, under what circumstances it occurs and how does energy generated compare to aerobic and anaerobic respiration
- No electron transport chain or TCA
- Occurs in the presences and absence of oxygen
- As they convert to NADH, they must be recycled for glycolysis pathway
- Recycling can be performed by either respiration or fermentation
- Photosynthesis combines phototrophy and carbon fixation to produce carbon compounds
- Light reactions capture light energy and use it to capture light energy and use it to create a proton motive force
- Photosystems: composed of numerous antennae that absorb light energy (light energy is passed to electron in reaction center and electron is sent to ETC)
- Light hits the chlorophyll pigment, generating electrons that are sent to the ETC to create energy
- Oxygenic photosynthesis: cyanobacteria. Oxygen is generated and released into the environment using chlorophyll and accessory pigments
- Anoxygenic photosynthesis: H2O not used as an electron source and O2 is not produced, only uses one photosystem carried out by certain bacteria
- Bacteriorhodopsin: archaea that involves a membrane protein which functions as a light-driven proton pump (ETC is not involved) 21.) Anabolism
- Energy from catabolism is used for biosynthesis pathways
- Using a carbon source and inorganic molecules organism synthesize new organelles and cells
- Carbon source→ precursor metabolites (only 12) → monomers → macromolecules —> supramolecular systems → organelles → cells
- Biosynthesis Efficiency
- Large molecules are made from small molecules (saves genetic storage capacity, biosynthetic raw materials and energy)
- Many enzymes do double duty (amphibolic) for both catabolic and anabolic processes
- Some enzymes function in one direction only (can be regulated independently)
- Anabolic pathways are irreversible because since we are using energy we don’t want to waste it
- Catabolism and anabolism are physically separated (compartmentation)
- Pathways operate simultaneously yet independently
- Catabolism and anabolism use different cofactors (catabolism produces NADH, NADPH used as electron donor for anabolism
- Large assemblies (ribosomes) form spontaneously from macromolecules by self-assembly 22.) Precursor metabolites
- 12 metabolites
- Critical steps in anabolism
- Carbon skeleton are used as starting substrates for biosynthetic pathways
- Intermediates of the central metabolic pathways (glycolysis and TCA)
Chapter 8
- DNA-what it is, what it looks like, generally how it is packaged
- Relationship between DNA, RNA protein
- DNA→ RNA→ proteins (flow of genetic information)
- Central dogma
- Griffith’s experiment
- Worked with smooth (S) and rough strains of S. pneumoniae
- Something that could transform a nonpathogenic R strain into a pathogenic S strain - S strain has a capsule, kills a mouse - R strain has no capsule, not killed - S Strain is heat-killed, does not kill mouse - Live R strain and heat killed S strain mixed, kills mouse - Live S and R cells were isolated from dead mouse - Cells lysis when killed and the R strain picks it up turning it into S strain
- Suggest that there is a transforming material, but is it proteins, RNA, or DNA?
- Avery, MacLeod, and McCarty experiment
- R cells mixed with heat-killed S cells→ all colonies ended up being S strain
- R cells and transforming factor extracted from heat killed enzymes added with an enzyme that destroy different cellular macromolecules - protease= S colonies - RNase= S colonies - DNase= no colonies
- Confirmed that DNA is the transforming material
- Hershey Chase experiment
- Used radioactive labeling of either proteins or DNA in bacteriophages
- They let the labeled phages infect the bacterial cells, then determined where the tag ended up for each set up
- Only the labeled phage DNA went into the bacteria cells, further proving that DNA (not proteins) was the hereditary material
- Replication in detail-initiation, elongation, termination
- Semi-conservation: each time the DNA is copied, each copy carries one strand from the original molecule and one newly-made strand
- Bacteria are bi-direction due to DNA being packed into a circle
- Origin of replication
- Fork (theat structure) that shows the separation of DNA
- Multiple dnaA proteins bind at oriC, bending and separating strands (oriC has many AT pairs with only two hydrogen bonds)
- dnaB with dnaC and dna gyrase (releases tension in supercoil) unwind and separates strand
- Single strand binding proteins (SSB) attach preventing the strand from being “eaten” by things in the cytoplasm
- dnaG synthesize RNA primes which add to free 3’ hydroxyl groups that DNA polymerase III can add too (lagging and leading strands are synthesized by a single DNA polymerase III holoenzyme
- DNA polymerase I removes RNA primer and synthesizes DNA to fill the gap
- Okazaki fragments are joined by DNA ligase from 3’ to 5’
- Gene structure Bacteria vs. Eukarya
- Gene: basic unit of genetic information
- The nucleic acid sequence that codes for a polypeptide, tRNA, or rRNA
- The segment that codes for a single polypeptide is called a cistron
- Eukaryotic cells: genes that code for proteins (exons) are interrupted by noncoding regions (introns) which must be removed by splicing
- Bacterial/archaeal coding information in gene is normally continuous
- Template Strand vs. Coding Strand
- RNA polymerase synthesize in the 5’ to 3’ direction
- Reads the DNA strand in the 3’ to the 5’ direction
- Promoters tell which strand to copy
- Coding strand: same sequence as mRNA
- Template strand: the strand being used to copy
- Leader sequences: transcribed but not translated like the Shine-Dalgamo sequence (help localize)
- Coding region starts with AUG and ends at a stop codon with a trailer sequence (not translated) to prepare for release
- Differences between RNA and DNA
- DNA: deoxyribose sugar and thymine base
- RNA: ribose sugar and uracil base
- Transcription in detail-initiation, elongation, termination
- Promoters
- Conserved segments of DNA at two different locations
- 35 sequence and then 10 sequence (pribnow box) of all ATs with 16-18 bp between
- RNA polymerase
- Unwinds DNA, moves along the template strand, synthesizing mRNA
- Initiation
- Promoter in the 5’ to 3’ direction
- RNA polymerase separates the DNA and lays down a complementary strand of RNA
- Different sigma factors can direct RNA polymerase enzymes to different genes
- Sigma factors: recognizes promoter regions
- Cor enzymes: allows it to make mRNA and elongate it all
- RNA polymerase= five different polypeptides
- Elongation
- After binding, RNA polymerase unwinds the DNA
- Transcription bubble produced (moves with the polymerase as it transcribes mRNA from template strand creating a temporary RNA/DNA hybrid)
- Termination
- Rho dependent: involves use of Rho proteins (kick RNA poly off the a strand by pulling DNA to Rho protein)
- Rho independent: involves other means that doesn’t include Rho proteins
- Hairpin loops on mRNA and want to pull away from DNA
- Structural fixtures that kicks polymerase from the strand
- Eukaryotic cells have 3 different RNA polymerase
- RNA poly I works like Rho dependent
- RNA poly III (involved with tRNA) works like Rho independent
- RNA II (involved with mRNA) cleaves the mRNA
- Bacteria goes directly to translation
- Eukaryotic post transcriptional processing
- 5’ cap of 7 methylguanosine and poly-A tail at 3’ added so that mRNA is not degraded
- Introns are spliced out and exons joined together
- The Ribosome
- Site of protein synthesis
- 70S ribosomes: 30S and 50S subunits
- Ribosomal RNA have 3 functions
- Contributes to the structure of ribosome
- 16 rRNA (in 30S subunit) ribosome binding site (binds to Shine Dalgarno site on mRNA for protein synthesis initiation)
- 23S rRNA (in 50 subunit) catalyzes peptide formation
- Codons
- 3 base pairs long that specifies for an amino acid
- Anticodon on tRNA is complementary
- Start codon: AUG, start site for translation
- Termination
- Recognition of one of three step/nonsense codons
- Release factors
- GTP hydrolysis
- Hits stop codon in A site, pause ribosome, RF1 and RF2 reads it, which triggers the hydrolysis of bonds between mRNA and tRNA, then RF3 will kick RF1 and RF2 from the peptide chain, also release the ribosome
- Protein folding processing transport
- Folded into their secondary and tertiary forms, which depend on a number of interactions between the amino acids in the primary polypeptide chain:
- Weak, non-covalent interactions
- Amino acid side groups
- Disulfide bridge
- Hydrogen bond
- Ionic bond
- Molecular chaperones: proteins that aid the correct folding of nascent proteins
- Can reverse incorrect folding and protects cells from thermal damage
- Protein transport: basic steps of locating/transport process are similar in each domain
- Differences between eukaryotes and prokaryotes in relation to aspects of transcription and translation
- Prokaryotes can be polycistronic (coding for more than one protein at a time), while eukaryal mRNA are monocistronic
- Translation and transcription occurs at the same time in prokaryotes Chapter 10
- Mutations-every type we talked about and possible effects (general)
- Stable, heritable changes in sequence of bases in DNA
- Point mutations: alterations of a single pair of nucleotides either through the addition or deletion of nucleotides
- Silent: change nucleotide sequence of codons, but not encoded in amino acid
- Missense: single base substitution that changes codons for one amino acids into codon for another amino acid
- Nonsense: converts a sense codon to a stop codon
- Frameshift: results from insertion or deletion of one or two base pairs in the coding region of the gene
- Larger mutations, while less common, include insertions, deletions, inversions, duplications, and translocations of nucleotide sequences
- Spontaneous mutations do occur but at a low rate due to the proofreading capability of DNA polymerase
- Induced Mutations (chemical agents, occurs at a higher rate than what is found spontaneously) - Base analogs: structurally similar to normal bases and mistakes occurs when they are incorporated into growing polynucleotide chain - DNA modifying agents: alter a base causing it to mispair - Intercalating agents: distort DNA to induce single nucleotide pair insertions and deletions - Physical Agents (UV light causes thymine dimers and X-ray does everything bad)
- Conditional mutations: expressed only under certain environmental conditions
- Auxotrophic mutations: unable to make an essential macromolecule such as an amino acid or nucleotide - Has a conditional phenotype - Wild type strain from which it arose is called prototroph and does not need the nutrient to survive
- Wild Type: most prevalent form of gene
- Forward mutation: wild type to mutate form
- Reverse mutation: mutant phenotype to wild type (either mutation in mutation or suppressor mutation)
- Repair system-every type we talked about/think about differences between each system
- Excision repair: corrects damage that causes distortion in double helix by removing and cutting it out (type of proofreading)
- Mismatch: enzymes scans newly synthesized DNA for mismatch pairs; removed and replaced by DNA polymerase and ligase
- DNA is hemimethylated (old strain has methyl and new doesn’t yet) so MutS recognized distortion and Mut H jumps on with Mut L linking the two and cut it out
- Nucleotide excision: UvrA and UvrB scans DNA for damage on both side and pauses; UvrC attached and cuts the damaged region and UvrD removes it
- Base pair excision: damaged single base are recognized and removed from DNA molecule using DNA glycosylase which removes the base, leaving the sugar without a base
- Direct repair through photoreactivation (for thymine dimers by splitting the thymine dimers) and alkylated bases
- Recombination Repair: repairs DNA with damage in both strands or gaps opposite a lesion
- Plasma membrane have receptors that allow DNA to bind
- DNA transglucase moves it into the cell, single strand DNA binding protects the strand and Rec A will induce stand invasion
- Transduction: viral
- Lytic cycle: kills the cell and produces more viral material
- Lysogenic cycle: incorporates the viral DNA into the cell and then something triggers (latent)
- Generalized transduction:
- Information transferred can be from and to any part
- Occurs during lytic cycle
- Fragments of host of DNA mistakenly packaged into phage head
- Specialized transduction:
- Carried out only by temperate phages that have established lysogeny
- Only specific portion of bacterial genome is transferred
- Occurs when prophase is incorrectly excised
- Homologous recombination (reciprocal and non)
- Reciprocal: Involves a reciprocal exchange between pair of DNA molecules with the same nucleotide sequence, carried out by the Rec A protein through the double strand break model
- Two strains of DNA, where one strain breaks on both sides
- Rec BCD will degrade the strain and single stranded binding protein prevents Rec BCD from going to far
- Rec A promotes strain invasion, so the two different strains will form the D-loop and holiday junctions with either nonrecombinant chromosomes or recombinant chromosomes
- Nonreciprocal: incorporation of a single strand of DNA in the chromosome, forming a stretch of heteroduplex DNA (fox model)..
- Transposons
- Segments of DNA that move about the genome in process and can be integrated into different sites in the chromosomes
- Insertion sequence: short sequence of DNA that contains only the gene for enzyme transposase with inverted repeats, and only functions to recognize and insert at complimentary places in chromosomes
- Cut and paste movement
- Composite Transposons: have the transposase gene and other genes included, usually consists of two IS elements on each side of the gene with inverted repeats
- Cut and paste
- Replicative Transposons: contains a transposase, a resolvase gene, and inverted repeats of each side
- Cutes at insertion sequences and strain invasion occurs and intertwined
- Able to make many copies of itself
- Basically cause mutations, turns genes on and off
- Plasmids have several different transposons that target sites so transposons frequently move between plasmids
- F Plasmids, HrF Plasmids, and F’ Plasmids
- Conjugate plasmids can transfer copies of themselves to other bacteria during conjugation
- F factor contains the information for formation of sex pilus
- Attach F+ cell to F- cell for DNA transfer during conjugation
- Needs direct cell to cell contact
- The F plasmid carries genes to form sex pilus bridge between two cells
- Copied via rolling circle method and sent across the bridge into the recipient cell (nicks a single strand of DNA and move it across, while replicating in other cell
- Turns F- cell into an F+ cell
- Types IV secretion system that makes contact between cells that the DNA can move across
- HFr: donor HFr cell has F factor integrated into its chromosomes and a complete copy of the F factor is not transferred (F- does not becomes F+)
- F’ Conjugation: F factor and a few extra genes and occurs when the f factor incorrectly leavers the host chromosome
- Turns f- into f’
- F plasmid can integrate into the host chromosomes, creating new opportunities to pass genetic information
