Microtest3INTRANET Flashcards
What did Girolamo Fracastoro come up with?
Diseases are caused by transferable spore like particles that could transmit infection
What did Van Leeuwenkoek come up with?
Invented microscope and was the first to describe microbes.
What did Semmelweis come up with?
Hand washing prevents puerperal (childbirth) fever.
What did Lister come up with?
Antiseptic in surgery.
What did Pastuer disprove?
Spontaneous generation.
Who is the father of microbiology?
Van Leeuwnekoek.
Who came up with the germ theory?
Pasteur.
What did Kock come up with?
Koch’s postulates, and TB vaccine.
What did Griffith come up with?
Bacteria are capable of transferring genetic information.
Who came up with anthrax, and rabies vaccines?
Pasture.
What did Avery, McCarty, and Macleod come up with?
Transforming substance is DNA.
What did Watson and Crick come up with?
Structure of DNA.
What did John Cairns come up with?
Bacterial chromosome is circular.
What shape will Coccus (cocci) bacteria be?
Spherical.
What shape will Bacillus (bacilli) bacteria be?
Rod-shaped.
What shape will Spirillum (spirilla) bacteria be?
Spiral.
What shape will coccabacillus bacteria be?
rod-shaped with round ends, mistaken for coccus.
What shape will spirochete bacteria be?
spiral shaped cell with unique motility.
What shape will pleomorphic bacteria be?
Vary in shape.
With Gram positive what will surround the bacteria’s cell membrane?
Thick peptidoglycan layer.
What color will Gram positive bacteria stain?
Purple.
What will create a negative charge in gram positive cell walls?
Teichoic acids.
What will surround the cell membrane with gram negative cell walls?
Thin peptidoglycan layer.
With gram negative cell wall what will surround the thin peptidoglycan layer?
Outer membrane.
What is embedded in the outer membrane of a gram negative cell wall?
Lipopolysaccharide (LPS).
What will the lipopolysaccharide (LPS) embedded in the Outer membrane of a gram negative cell wall be composed of?
Lipid A and O specific polysaccharide/
The LPS of the gram negative cell walls is toxic and is known as what?
Endotoxin.
What is the toxic portion of the LPS?
Lipid A.
What color will gram negative cell walls of bacteria stain?
Pink.
What will acid fast cell walls stain like?
Due to high lipid content they do not readily take up stain.
How can you get an acid fast cell to stain?
Requires unique dyes and heat to stain.
What is the genus in which all species are acid-fast?
Mycobacterium
What are bacterial cells that lack a cell wall like?
Cell membranes have high sterol content which gives rigidity to the cell.
What is the normal model of a phospholipid bilayer?
Fluid mosaic model with proteins moving around.
What are 2 ways a cell membrane will be selectively permeable?
- Facilitated diffusion. 2. Active transport.
Which type of selective permeablity will rarely be used in bacteria?
Facilitated diffusion.
What is active transport of bacterial cell membranes like?
Transport proteins will move substances acrossed the membrane and energy is required.
Where will oxidative phosphorylation take place in bacteria?
Cell membrane.
Where will enzymes used in DNA replication of bacteria be located at?
Cell membrane.
What is a bacteria mesosome?
Invaginations of the cytoplasmic membrane that can form into vesicles.
What is a possible role of a mesosome?
Cell division.
What is periplasmic space?
Space between the inner and outer membranes in gram negative cells.
What is a nucleoid?
Region of bacterial cell containing DNA.
What is the plasmid?
Small extrachromosomal DNA.
What type of replication will plasmid be involved in?
Autonomous.
What are bacterial ribosomes used for?
Organells composed of ribosomal RNA and protein.
What are bacterial storage granules?
accumulations of high molecular weight polymers.
What are 2 other names for storage granules?
Inculsion bodies, granular inclusions.
Flagella is for motility and what?
Can act as a virulence factor (Capablitiy to cause disease).
Bacteria pili serve what purpose?
Adherence factors, and a virulence factor.
What do sex pili do?
Transfer plasmids.
Bacteria capsules are aka?
Glycocalyx.
Bacteria capsules are external structures that do what?
Protect walls around some Gram + and gram -.
How will bacteria capsules act as virulence factors?
They impede phagocytosis and the bacteria will survive longer.
What 2 gram + bacteria have the external structure endospore?
genera bacillus, and clostridium.
What is the role of endospores?
Protective not reproductive.
Endospores are protective against what?
Heat, drying, disinfectants.
The earliest classification system was proposed by who?
Linnaeus.
Originally linnaeus came up with how many kingdoms?
Two.
More recently who came up with the idea of 5 or 6 kingdoms?
Woese.
Most recently a 3 domain system was proposed due to what?
DNA comparison.
What are the 3 domain systems?
Bacteria, Archaea, Eukarya.
What is the order of bacterial nomenclature?
Kingdom, Phylum, Class, Order, Family, Genus, species, strain.
What nomenclature do we use to name an organism in this class?
Genus and occasionally strain.
What morphological characterisitics are used for bacterial identification?
Colony characterisitcs, Cell shape, presence of capsule, endospore, staining (G+ or G-), Locomation.
Why will we do biochemical testing for bacterial identification?
Test for utilization of different substrates.
When classifying bacteria by molecular taxonomy why use size?
Size of bacterial genomes differ among genera and species.
What else will differ among genera and species with molecular taxonomy?
G+C content.
What 2 things are left to look for with molecular taxonomy besides size, and G+C content?
Nucleic acid similarity and protein similarity.
How is Diagnostic molecular pathology classification done?
In vivo hybridization. Create a labeled fluorescent probe of KNOWN DNA of suspect infection. Then apply the probe to tissue and see if a match with complementary strands is present in the tissue.
How is the Polymerase Chain reaction (PCR) classificatn done?
allow millions of copies of bacteria to be made. Use a primers specific for target.
How are immunological tests done to identify bacteria?
Analyze blood serum to search for specific antibodies present.
What indicates what bacteria will have a specific set of antigens?
Serotype.
What is a bacteriophage?
A virus that infects a bacterium.
Bacteriophages are aka?
Phage.
Phage are specific to what?
Host.
What is bacteriophage typing?
Infect a microbe with a phage and you can determine what the bacteria is.
What is antibiotic sensitivity testing?
Subject sample bacteria to various antibiotics and test for resistance or suceptibility then you can find out what type of bacteria it is.
What is the energy source for bacterial metabolism?
ATP.
How will bacteria get ATP?
Carbohydrate, lipid and protein catabolism. Also synthesis of cellular componenets a type of anabolism.
What is it called when catabolism and anabolism are tightly linked together?
Metabolism.
What is the primary carbohydrate used in energy production?
Glucose.
Metabolism of glucose occurs when with or without oxygen?
Both with and without.
One molecule of glucose is converted into what?
2 pyruvate and 2 ATP, amd 2 NADH.
Both Pyruvates from 1 glucose enter the TCA cycle aka krebs cycle and what happens to pyruvate?
Completely oxidized to water and CO2.
What is the net gain of 1 glucose (2 pyruvates) in the krebs cycle?
2 ATP, 6NADH, 2FADH2.
After the krebs cycle what enters the electron transport chain?
FAHD2.
What is the final electron acceptor in the electron transport chain for bacteria?
Oxygen.
The electron transport chain synthesizes ATP how?
By proton motive force generated by passing electrons along chain.
What is the name of the theory of the way the electron transport chain works?
Chemiosmotic theory.
What is oxidative phosphorylation?
The use of reducing power of NADH and FADH2 to synthesize ATP.
What is aerobic respiration?
Transferring electrons from NADH and FADH2 to oxygen.
What is anaerobic respiration?
In absence of O2 electrons are transferred to an inorganic terminal electron acceptor like SULFUR.
What is fermentation?
In absence of O2 electrons are transferred to an organic terminal electron acceptor.
Fermentation is used by what type of organisms?
Those that cant respire.
How much ATP is made with Aerobic respiration?
38 atp.
How much ATP is made with Anaerobic respiration?
30 or less.
How much ATP is made with fermentation?
2-4 ATP.
What are Psychrophiles?
Microbes that live between -5 - 15 degrees C.
What are Mesophiles and Thermophiles?
Mesophiles- Microbes that live between 25-45 degrees C. Thermophiles- between 45-70 degrees C.
What type of bacteria lives in Humans?
Mesophiles.
What are obligate aerobes?
Microbes that have an absolute requirement for O2.
What are obligate anaerobes?
Microbes that can not multiply if O2 is present.
What is Facultative anaerobes?
Microbes that grow better if O2 is present, but can grow without it.
What are microaerophiles?
Microbes that require small amounts of O2 (2-10%)
What are aerotolerant anaerobes?
Microbes that are indifferent to O2 can grow with or without O2.
Will aerotolerant anaerobes use O2?
No they do not use it to transform energy.
What is O2-?
Superoxide.
Hydrogen peroxide is generated when using O2 and it is what type of agent?
Oxidizing agent.
What will damage cells more superoxide or hydrogen peroxide?
Superoxide anions.
How will cells prevent damage from Toxic oxygen derivatives?
They possess enzymes to degrade the toxins.
What Enzyme will convert O2- to H2O2?
Superoxide dismutase.
What enzyme will convert H2O2 to H20 and O2?
Catalase.
What will the internal pH of microbes be?
7.0 pH.
What pH will the internal pH of neutrophiles, Acidophiles, and Alkalophiles be?
near 7.0.
What type of pH will the neutrophiles, acidophiles and alkalophiles be found living in?
Neutro- 5-8. Acid- below 5.5. Alkal- above 8.5.
What type of bacteria live in the gut according to pH?
Neutrophiles.
How will neutrophiles live in the acidic environment like the gut?
They have unique mechanisms to change pH.
What type of microbes need water?
All.
What are Halophiles?
Microbes that require high levels of salt to live and multiply more than 10%.
What are Osmotolerant bacteria?
Those tolerant to high salt environments (up to 10%).
What is a Pure Culture?
A populatin of organisms descended from a single cell and is therefore separated from all other species.
What did Robert Koch do?
Developed solid media for bacterial growth.
What did Robert Koch use for the solid media?
Agar-agar.
What was and still is agar-agar used for?
Cooking it is derived from seaweed.
Agar-agar was contained in dishes that were invented by who?
Koch’s lab assistant Julius Richard Petri.
What is Binary fission?
After a bacterial cell has increased in size and doubled all of its parts it divides.
When will bacterial chromosome be replicated?
Early in life of the cell.
The cell during binary fission grows and elongates to what size?
About twice its size.
With Binary fission DNA is partitioned and cell lays down new plasma membrane and cell wall material will be where?
Regions between attachmet site of 2 daughter genomes.
What is the last step of Binary fission?
Cell wall grows.
What is the growth of bacteria like?
Exponential.
What is the time called that it takes the bacteria to double in number?
Generation time.
In the closed system of a lab bacteria will grow following a pattern called what?
Growth curve.
What is the first phase of the growth curve?
Lag Phase.
What is the lag phase?
Cells “ramp up” by synthesizing macromolecules required for division and ATP.
What is the second phase of the growth curve?
Exponential phase.
What is th exponential phase like?
Cells dividing at a constant rate, growht is balanced with available nutrients.
What is the 3rd phase of the growth curve?
Stationary phase.
What is the stationary phase like?
Cells have exhausted supply of energy and nutrients, number of cells remains relatively constant.
What is the 4th and last phase of the growth curve?
Death phase.
What is the death phase like?
Population decreases as cells die off at constant rate.
What are 2 methods used to measure growth?
- Direct-count method using microscope and hemacytometer. 2. Indirect- Cell counting using serial dilution.
Microbial DNA is composed of how many nucleotides and which ones are they?
4 A,T,G,C.
Which nucleotides pair with each other?
A-t, G-C.
Will microbial DNA have the double stranded helical molecule?
YES.
What is a codon?
A set of 3 neucleotides on a strand that encodes a specific amino acid.
Where will DNA replication begin at?
A specific nucleotide sequence called a replication origin (ORI).
For DNA replication synthesis occurs where?
ON both strands.
How is DNA replication of both strands done?
By a variety of enzymes and proteins.
DNA replication is it conservative or semi-conservative?
Semi-conservative.
What direction will DNA replication proceed in?
5’ to 3’.
Since both strands of DNA are replicated what will the 2 strands be called?
Leading and Lagging.
What is the leading and what is the lagging strand?
Leading- synthesized continuously. Lagging strand- discountinuously synthesized.
Lagging strand is aka?
Okazaki fragments.
For gene expression DNA info is transferred to what?
An RNA copy of the gene.
DNA to RNA is called what?
Transcription.
RNA to Protein is called what?
Translation.
What is synthesized from a DNA template by RNA polymerase?
mRNA.
What are the RNA nucleotides?
A,U,G,C.
What happens to the newly formed mRNA?
Moved to ribosomes for translation.
How often will bacteria have more that one gene encoded on a single RNA?
Frequently.
What is a set of adjacent genes coordinately controlled by regulatory protein and transcribed as a single RNA message?
Operon.
Are Operons inducible or repressible?
Both.
What is an inducible operon?
An RNA message that is off and can be induced to function.
What do inducible operons need?
an inducer to prevent a repressor protein from binding to the operator.
What is a repressible operon?
An RNA message that is on and can be repressed to stop function.
What do repressible operons need?
They require that the operator be bound by a repressor.
What is feedback inhibition of translation?
End products inhibit enzymes early in pathways preventing production of more endproducts.
Where will spontaneous mutations occur at?
In the natural environment.
What is a base substitution mutation?
An incorrect base is incorporated into the DNA during replication.
With Base substitutions what is it called if only 1 base changes?
Point mutation.
What is a missense mutation?
A base substitution where it leads to substitiution of different amino acid in protein.
What is a nonsense mutation?
A base substitution where a stop codon instead of a normal amino acid codon happens.
What is a frameshift mutation?
Removal or addition of nucleotides that change the way the DNA sequence is read.
What is transposons mutation?
Segments of DNA that can move spontaneously from one site to another is the same or different DNA molecules.
Transposon mutations are aka?
Jumping genes.
What is an Induced mutation?
A change in DNA sequence that is a result of a mutagen such as radiation, or chemical agents.
Name 3 chemical mutagens and how they alter DNA molecules.
they alter the binding of the DNA. 1. Alkylating agents. 2. Base analogs. 3. Intercalating agents.
What are 2 types of radiation that cause DNA mutations?
UV light and X-ray.
How will UV light cause a mutation?
Thymine dimers.
How will X-ray cause a mutation?
Cause single and double stranded breaks in DNA.
Bacteria employ what 2 types of repairs of mutations?
- Mismatch (or excision repair). 2. SOS.
What is a way people can study the normal function of genes?
Cause mutation and see what they are not doing.
What are prototroph and auxotrophs?
Prototroph- cells that grow without added growth factors. Auxotrophs- cells that grow only with growth factors added in laboratory.
What are conditional lethal mutants?
Mutants defective for the synthesis of an essential macromolecule under specific conditions.
How many different ways to genetic recombination are there?
three.
What are the 3 different types of genetic recombination?
- Transformation. 2. Conjugation. 3. Transduction.
Transformation was first demonstrated by who?
Griffith.
What did griffith see?
Some unknown (later known as DNA) compound transforming bacterial cells.
What is naked DNA?
DNA not contained in a cell.
What does it mean for a cell to be competent?
Able to take up naked DNA.
Mechanisms of competence is not understood, but populations are naturally competent when?
During the exponential aka log phase of growth.
How can cells be induced into competence?
Treated with CaCl2, or subjecting cells to electrical current called elctroporation.
Conjugation requires what?
Contact between the 2 bacterial cells.
What type of DNA can be transferred with conjugation?
- Plasmid DNA. 2. Chromosomal DNA.
With conjugation what type of Plasmid is transferred?
The F plasmid (Fertility plasmid).
The donor cell that has the F plasmid is known as what?
F+ or male.
What is the recipient cell called that will get the F plasmid?
F- or female.
F plasmid has a series of genes that code for what?
Formation of sex pilus.
When will F plasmid allow chromosmal DNA to be transferred with conjugation?
Only if the F is integrated into the chromosome.
What is a cell called with a F plasmid that has integrated into the chromosome?
Hfr cell.
In order to transfer DNA a Hfr cell must do what?
excise(cut out) the F plasmid.
The excised F plasmid is called what?
F prime.
How is transduction done?
Transfer of DNA from cell to cell via bacteriophage.
What 2 ways can bacteriophages interact with cells?
- Lytic. 2. Lysogenic.
What will lytic be like?
Phage overtakes the cell.
With lytic once the phage overtakes the cell what happens?
Assembly of new phages occurs and the bacterial chromosomal DNA may be incorporated.
Eventually with lytic the cell will lyses and expel the new phages that contain the bacterail chromosomal DNA and then what could happen?
The phage is capable of transduction.
What is lysogenic transduction like?
Phage (viral) DNA integrates into host DNA (called temperate phase).
With lysogenic transduction how long will the phage DNA remain in the cell?
For a few to many generations.
Cells with the Phage DNA inside will eventually do what?
become lytic.
What happens if a viral gene is permanetly incorporated into bacterial DNA called lysogenic conversion?
This results in new bacterial strain.
What are the 2 types of transduction?
Generalized and specialized.
What is generalized transduction?
During production some phages accidentally package only bacterial chromosomal DNA not viral DNA in capsid.
What happens to phages that accidentally package only bacterial chromosmal DNA not viral DNA in capsid?
They can still infect cells, but injects bacterial chromosomal DNA into host.
What is specialized transduction?
The Phage packages both viral DNA and Bacterial chromosomal DNA.
With specialized transduciton phages package specific chromosomal DNA found where?
Near where viral DNA integrated during lysogenic phase.
What is biotechnology?
Use of biological techniques to solve practical problems and produce more useful products.
What has made it possible to genetically alter organisms to give them more useful traits?
Rapid development of DNA techniques.
What lead to the discovery of restricition endonucleases in bacteria?
recombinant DNA technology.
What is a common approach used to clone a specific gene?
Insert a set of DNA framents that together make up the entire genome of the organism being studied into a population of E. Coli cells. Then find the gene you want to clone.
What is a DNA library?
All genes of an organism being studied in a population of E. Coli.
What is an application of genetic engineering for biotechnology?
Stimulate bacterial cells to produce protein products not normally produced.
What is now available through bitechnology being mass produced in E. coli cells?
Insulin, human growth hormone, interferon, and factor VIII.
What is a subunit vaccine and where do they come from?
A purifed antigenic determinant that is separted from the disese-causing organism. They come from biotechnology.
What is replacement therapy?
Substituting less virulent microbes for virulent strains.
What is an Iatrogenic infection?
Brought forth by a healer. An infection that happens as a result from medical treatment.
What is a Nosocomial infection?
An infection from treatment in a hospital or hospital-like setting, but secondary to patients original condition.
Can iatrogenic and nosocomial infections be airborne transmissions?
Yes.
What is sterilization?
Absence of all life.
What is disinfection?
Killing/removing pathogens.
What is antiseptic?
Disinfectant applied to tissue.
What is bactericide?
Substance that kills/removes only bacteria.
What is sepsis?
Severe infection leading to systemic immune response.
What is asepsis?
Using aseptic technique.
What is microbiostasis?
Inhibition of microbe growth.
What is spectrum?
Range of activity against microbes.
What is activity?
Drugs tested to determine the lowest concentration that inhibits microbe called minimum inhibitory concentration (MIC).
What is combination therapy?
use of more than 1 antibiotic to increase spectrum or killing effect.
What is synergism?
increased killing effect by using multiple antibiotics.
What is antagonism?
1 antibiotic interferes with the action of another.
What is an autoclave?
A method of sterilization that uses steam with pressure.
What is moist heat?
A method of sterilization that uses steam, boiling water.
What is dry heat?
A method of sterilization that uses flame, oven.
How will antibiotics inhibit cell wall synthesis?
Prevent cross-linking of peptidoglycan by binding to enzyme receptor sites.
What type of antibiotics are inhibitors of cell wall synthesis?
Penicillin and derivatives (ampicillin and amoxicillin), cephalosporins, bacitracin, vancomycin, isoniazid.
What is the chemical structure of penicillin?
beta-lactam.
What type of bacteria is resistant to penicillin?
Those that produce Beta-lactamase.
What is the chemical structure of cephalosporins?
beta-lactam.
How are cephalosporin derivatives grouped?
Into generations by their antibicrobial properties.
What type of bacteria are resistant to Cephalosporins?
Those that produce Beta-lactamase.
Bacitracin is used how and why?
Only topically because it is toxic to the kidneys.
Vancomycin was initially used for what?
Fighting staphylococcus aureus.
Vancomycin is primarily used to treat what?
Systemic infections.
What is the reason vancomycin WAS used to fight staph?
It is quite toxic to kidney, nerve deafness, skin rashes, throbophlebitis.
What will Isoniazid inhibit?
Synthesis of mycolic acids in cell walls of mycobacteria.
Isoniazid is active against what?
Mycobacteria only.
What antibiotics are inhibitors of the cell membrane?
Polymyxin B and E.
How will polymyxin B and E work?
They replace Mg2+ and Ca2+ from membrane lipids disrupting the structure of the bacterial cell membrane.
Where and why will polymyxin B and E be used?
Skin because they are Toxic.
Name the antibiotics that are inhibitors of protein synthesis?
Streptomycin, tetracycline, chloramphenicol, and erythromycin.
Which of the antibiotics that are inhibitors of protein synthesis are broad spectrum?
All 4 of them.
How is streptomycin often used?
In conjunction with penicillin-related antibiotics in strepotoccal infection for synergistic effects.
Derivatives of streptomyocin are?
Kanamycin and gentamycin.
What can tetracycline cause?
Photosensitivity, renal toxicity, and stains teeth in young children.
What will chloramphenicol do?
Toxic and can cause aplastic anemia.
What is erythromycins role?
Given to those allergic to penicilline and has a mild toxicity.
Name 2 antibiotics that are inhibitors of nucleic acid synthesis?
Rifampin, quinolones.
What are Rifampin’s usage?
To treat TB in combination with other antibitotics.
Is Rifampin toxic?
No.
How will quinolones work?
They are inhibitors of nucleic acid synthesis and this inhibits DNA replication, and this makes them bacteriocidal.
Give a common example of quinolones?
Ciprofloxacin.
What type of drugs are the antimetabolites?
Sulfonamides (sulfa drugs).
Are sulfonamides antibiotics?
No they are precursors to antibiotics.
How are sulfonamides derived?
From sulfonic acid.
Sulfonamides are inhibitors of what?
Folic acid synthesis.
What type of spectrum will sulfonamides have?
Wide spectrum.
Will sulfonamides be able to fight protozoa infections?
Yes.
Give an example of a sulfonamide?
Dapsone- used to treat mycobacterium leprae (leprosy).
Will toxicity always be seen with toxic antibiotic use?
No.
What is sensitization of antibiotics?
Develop a rash, fever, anaphylaxis.
