Microbiology 305 FINAL EXAM
Terms
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- complement
- series of proteins that react in a sequential manner with antibody-antigen complexes to amplify or potentiate antibody activity (can cause lysis of cell or enhance recognition by phagocytes)
- immunity
- ability of an organism to resist infection
- Chase, Hershey
- scientists that indicated that DNA was the genetic material in bacteriophage T2 (1952)
- gel electrophoresis
- process of mapping plasmids and finding restriction sites and sizes. Able to cut bands out and DNA
- basophil
- non-phagocytic granulocyte which releases histamine, prostaglandins, serotonin, and leukotrienes from granules, which play roles in development of allergies and hypersensitivies
- transduction
- transfer of bacterial genes by viruses during the lytic cycle by accidental packaging of host DNA fragments into phage head
- innate immunity
- (natural/nonspecific immunity) the body's built-in ability to recognize and destroy pathogens or their products. it does not rely on previous exposure, but does activate adaptive immunity
- helper T cell
- T lymphocyte which stimulates the immune system and regulates other lymphocytes by secreting cytokines, recognizes antigens embedded in MHC II proteins, has CD4 protein coreceptor
- Dendritic cell
- phagocytic monocyte which resides in skin and mucosal surfaces and is involved in aging and tissue repair. Can recognize viruses as foreign
- lethal mutation
- type of mutation that kills the organism
- plasmid
- small, double-stranded, usually circular DNA molecules which replicate independently of host chromsomes
- Rec A protein
- protein necessary for genetic recombination which binds to the SSB protein
- tolerance
- discrimination between self and non-self response
- apoptosis
- programmed cell death
- neutrophil
- 1st responder, phagocytic granulocyte which migrates to sites of tissue damage and kills ingested microbes with lytic enzymes and toxic oxygen products
- exons
- coding sequences of genes in eukaryotes
- phagocyte
- leukocytes (macrophages, neutrophils, and dendritic cells) which engulfs and destroys foreign substances, resulting in inflammation. Some act as antigen-presenting cells
- replica plating
- process of making an imprint of all the colonies of a master plate onto velveteen, than transfering the impring to a fresh media to compare the two and find mutant colonies
- silent mutation
- type of mutation that produces a normal protein, making it more difficult to identify
- prokaryote
- cell type which has horizontal gene flow (donor to recipient)
- forward mutation
- type of mutation in which the wild-type gene mutates into a mutant form
- introns
- noncoding sequences in genes of eukaryotes
- revertant
- cell which has experienced reverse mutation through the return of the original base-pair
- hapten
- small organic molecules that cannot induce an immune response but can bind to antibodies. may become antigenic when bound to larger carrier molecules (e.g. penicillin)
- wild-type gene
- most prevalent form of a gene
- Competent
- term for cell that is capable of taking up DNA
- bacteriocin plasmid
- plasmid that codes for production of bacteriocin. Some are conjugative and some carry persistance genes
- Sanger dideoxy method
- tehnique for DNA sequencing using flourescent dyes as markers
- fertility plasmid
- conjugation plasmid (F factor) that carry genes to make sex pillus
- DNA ligase
- the "glue" which seals new base-pairings during DNA replication
- chemokine
- soluble chemoattractant produced by damaged host cells to attract neutrophils to the site and neutrophils to attract macrophages (e.g. interleukin-8)
- virulence plasmid
- plasmid that carries virulence genes (e.g. genes that code for toxins or confer resistance to host)
- respiratory burst
- when an organism takes up a lot of oxygen in a short amount of time, producing free radicals
- primer
- starting point for DNA polymerase to bind
- engineered plasmid
- plasmid that stays within the host and contains genes for maintenaince through controlling replication
- microbial flora
- microorganisms that are usually found associated with healthy body tissue (skin, oral cavity, respiratory tract, urogenital tract - NOT internal organs, blood, lymph, or nervous systems)
- transposon
- sequence of DNA that can move from one place to another in a genome, sometimes causing mutation "jumping gene". has protein-coding DNA segments flanked by inverted, repeated sequences that can be recognized by transposase
- nonselectable mutation
- mutations that lead to a change in a phenotype that confers no advantage to the organism (loss of color)
- Class II MHC protein
- protein found only on the surface of B lymphocytes, macrophages, and dendritic cells that serves as a reference point for self (looked for by T helper cells)
- spontaneous mutation
- a mutation that is a result of errors in DNA replication or damage to DNA
- resistance plasmid
- plasmid (R factor) with genes for resistance to antibiotics. Some are conjugative and they usually do not integrate into the chromosome
- mutation
- a stable, heritable change in the nucleotide sequence (genotype) of an organism that is passed onto offspring. phenotype may or may not be affected
- adaptive immunity
- (specific immunity) aquired ability to recognize and destroy a pathogen or its products. Requires exposure of the immune system to the pathogen
- B lymphocyte
- cell of specific immune system which originates in bone marrow and matures in lymphoid tissue, and either produces antibodies or cells with memory of the pathogen, not very mobile
- supressor mutant
- second-site revertant which compensates for a mutation in another location by producing the same protein or effect
- biotechnology
- use of organisms to form useful products
- epitope
- site on antigen recognized by antibody or TCR (4-6 amino acids)
- base-pair substitution
- change in one base pair in the DNA (point mutation)
- Major Histocompatability Complex
- genetic region that encodes "self" proteins. MHC proteins function as molecular reference points (several 100 genes in human pop)
- betalysin
- blood protein that inhibits microbial growth
- composite transposon
- transposon flanked by two separate IS elements which may or may not be exact replicas, all of which move in one complete unit
- transposase
- enzyme which recognizes host DNA and cuts and glues transposons in and out of genome
- reverse mutation
- type of mutation in which a mutant phenotype mutates back in the wild-type phenotype (most likely to happen with point mutation)
- nonsense mutation
- type of point mutation which results in an incomplete protein
- Natural Killer cell
- lymphocyte which recognizes and destroys foreign cells or infected host cells in a nonspecific manner
- fusobacterium
- filamentous, strict anaerobic bacteria living under plaque
- eosinophil
- granulocyte which defends against protozoa and other parasites
- insertion sequence
- short segment of DNA which carries genes coding only for proteins implicated in transposition activity
- artificial transformation
- transformation done in laboratory with species that are not normally competent (E. coli)
- gene
- linear sequence of nucleotides with a fixed start point and end point
- opsonization
- walling off infection to aide phagocytes
- transition
- one purine is substituted for another purine or one pyrimidine for another pyrimidine at a point mutation
- inflammation
- innate response to tissue injury caused by pathogen or physical trauma with signs of redness, warmth, pain
- genotype
- specific set of genes an organism possesses (nucleotide sequence)
- pathogen
- disease-producing microorganism (parasite)
- selectable mutation
- mutation that confers some type of advantage to the organism (drug resistance)
- resistance mutation
- type of mutation that causes resistance to pathogen, chemical or antibiotic
- Macrophage
- phagocytic monocyte which resides in tissues, spleen, and lymph nodes and stimulates other cells
- molecular cloning
- isolation and incorporation of a fragment of DNA into a vector where it can be replicated
- point mutation
- change in one base pair in the DNA (base-pair substitution)
- wild-type strain
- strain isolated from nature
- toxic oxygen products
- (free radicals) superoxide radical, hydrogen peroxie, singlet oxygen, hydroxyl radical, hypochlorous acid - produced by respiratory bursts
- lambda d gal
- defective virus with galactose genes
- metabolic plasmid
- plasmid that carries genes for metabolic processes (e.g. genes that code for degradative enzymes for pesticides)
- autoradiography
- method for detecting radioactively labled molecules
- pathogenicity
- ability of a pathogen to cause disease
- Polymerase Chain reaction
- technique that synthesizes large quantities of a DNA fragment without cloning it
- leukocyte
- white blood cell involved in both innate and adaptive immunity. Travels between blood, interstitial spaces, and lymph.
- hybridization probe
- radioactive DNA, a strand of nucleic acid that can be labeled and used to hybridize to a complementary molecule from a mixture of other nucleic acids
- virulent bacteriophage
- bacteriophage that reproduces using the lytic life cycle
- virulence
- degree of pathogenicity displayed by a pathogen (quantitative measure)
- electroporation
- process of giving an electric shock to bacteria so that they will uptake DNA
- auxotroph
- nutritional mutant that cannot synthesize a product by biosynthetic pathway and requires the product as a nutrient in minimal growth media to survive
- genome
- all genes present in a cell or virus - genetic blueprint
- bacteriocin
- protein that destroys other bacteria, usually closely related species - coded for by plasmids
- antibody
- (immunoglobulin) protein molecule that is able to combine with antigenic determinants, produced by B cells, found in serum, gastric secretions, milk (80% Iin serum are IGG) 4 constant domains
- temperate bacteriophage
- bacteriophage that reproduces using the lysogenic life cycle
- vector
- delivery vehicle for production (plasmid or virus)
- screening
- observation of changes in organism phenotype
- leukocytin
- phagocyte-killing proteins on bacteria (pus)
- pattern-recognition molecule
- very specific molecules on phagocytes that recognize pathogens, connect with pathogen-associated molecules through a toll-like recepter
- hydrolases
- the lysozymes, proteases, phosphatases, nucleases, lipases of phagocytes
- TH2
- Helper T cell which assists B cells
- homologous recombination
- combination of closely related DNA sequences from two distinct genetic elements (sources)
- calcium chloride
- chemical treatment given to bacteria to make them more permeable to DNA
- recombination
- process in which one or more nucleic acid molecules are rearranged or combined to produce a new nucleotide sequence
- Avery, MacLeod, and McCarty
- scientists that showed that DNA carries the information for transformation. they used cell free extracts. (1944)
- mutagen
- chemical or physical agent that damages or alters the chemistry of DNA, or that interferes with DNA repair mechanisms
- prototroph
- parent from which an auxotrophic mutant has been derived (non-mutant strain that grows in minimal media without supplements)
- recombinant DNA technology
- procedures used to carry out genetic engineering
- phenotype
- set of observable characteristics of an organism
- opportunistic pathogen
- member of normal microbiota that produce disease under certain circumstances (absence of normal host resistance)
- morphological mutation
- type of mutation that changes colonial or cellular morphology
- SSB protein
- single-stranded binding protein which forms a protein complex with Rec A in genetic combination
- genetic engineering
- deliberate modification of organism's genetic information by directly changing its genome (gene splicing)
- conditional mutation
- type of mutation expressed only under certain conditions (e.g. high temperatures)
- 10 um
- largest size in diameter of particles that can reach lungs
- transposition
- process by which a gene moves from one place to another in the genome. Is a rare event that is importnat in evolution and genetic analysis
- Class I MHC protein
- protein found on all nucleated cells that serves as a reference point for self
- cloning
- making a genetically identical copy of DNA or or an organism
- diversity
- system generates enormous numbers of different molecules that recognize billions of different antigens (10^15 naturally made antibodies)
- cytokine
- soluble chemoattractant produced by activated macrophages to activate other cell types
- shotgun cloning
- making a gene library by random cloning of DNA fragments
- replicative transposition
- transposition where the transposon is replicated. it leaves a copy of itself in DNA and adds another
- Griffith
- scientist who discovered that through the process of transformation, a nonvirulent form of bacteria (Streptococcus pneumoniae) could become virulent (1928)
- conservative transposition
- transposition where there is only one copy of the transposon. When it cuts itself out of DNA, none is left behind
- heteroduplex
- double-strand
- transducing particle
- virus with host DNA which can't cause normal viral effects (1 out of 1 -10 mil)
- cloning vector
- a DNA molecule that, on being replicated in a cell, brings about the replication of other genes inserted into the DNA molcule (recombinant plasmids)
- eukaryote
- organism with two sets of genes
- Cytotoxic T cell
- T lymphocyte which kills infected cells, intracellular pathogens and cancer cells. recognizes antigens embedded in MHC I proteins. has CD8 protein coreceptor
- restriction enzyme
- the "scissors" which recognize certain sequences of DNA and cut either blunt or sticky ends (endonuclease)
- sticky ends
- free ends of DNA that fit together like puzzle pieces
- transformation
- the uptake of free DNA molecules from the environment and incorporation into a recipient cell. This plays an important role in horizontal/lateral gene transfer
- T lymphocyte
- cell of specific immune system which matures in the thymus and is responsible for antigen-specific cellular interactions (cytotoxic T cells and helper T cells) (70-85% of lymphocytes in blood)
- transversion
- one purine is substituted for a pyrimidine (or vice versa) at a point mutation
- missense mutation
- type of point mutation in which the the wrong protein is coded for
- pathogen-associated molecule pattern
- molecule on pathogens recognized by the pattern-recognition molecule of phagocytes
- DNA library
- mixed collection of bacteria that house many different cloned DNA fragments (gene library)
- Crick, Watson
- scientists that determined the structure of DNA (1953)
- CD4/CD8 protein coreceptors
- help stabilize binding between MHC/antigen binding in Helper T and Cytotoxic T cells
- bacteremia
- condition of bacteria in the blood
- TH1
- Helper T cell which assists cytotoxic T cells
- specialized transduction
- tranduction (also known as restricted transduction) which is only carried outby temperate phages that have established lysogeny with the cell. Occurs when the prophage is incorrectly excised from host DNA, taking genes adjacent to the prophage with it.
- frameshift
- a deletion or insertion of base pairs which alters the reading of the frame (3 at time), producing different amino acids
- agglutination reaction
- clumping of antibodes and antigens
- memory
- response to second exposure is so fast that there is no noticeable pathogenesis (vaccination)
- genetic recombination
- when one gene, a set of genes or a whole genome is combined with another genome
- Ames test
- test for mutagenicity used as a screen for carcinogen potential using auxotrophs for their point mutations
- lymphocyte
- major cells of the specific immune system. Includes B cells, T cells, and natural killer cells
- heliobacter pylori
- bacteria that can cause stomach ulcers
- antigen-presenting cell
- monocyte which engulfs, processes, and presents antigens on surface to lymphocytes
- systemic infection
- infection of the blood and lymph
- Southern Blotting Technique
- technique developed by Edwin Southern which is used to detect specific DNA fragments by binding to complementary sequence and showing existance. Often uses hybridization probes.
- selection
- the process of placing of organisms under conditions where the growth of those with a particular genotype will be favored
- specificity
- immunity directed against a particular antigen
- curin
- eliminates plasmids from the cell
- plaque
- bacterial film
- eukaryote
- cell type which has vertical gene flow (mother to daughter)
- oligonucleotides
- sequences of nucleotides with different numbers of bases
- biochemical mutation
- type of mutation that changes metabolic capabilities of cell
- prokaryote
- organism with one set of genes