Microbiology
Terms
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- Viral structure
- 1. Genome 2. Protein coat 3. (some have additional membrane)
- capsid
- protein coat
- urination barrier
- removes bacteria from urethra
- Influenza
- Virus caused by Orthomyxoviridae, structure of spikes mutates rapidly
- Cro gene
- produces Cro protein
- Cell mediated immune response
- macrophages cruise through bloodstream, sccop up and phagocytose any odd particles, particles are digests and parts are presented on surface of macrophage in its MHC class II protein
- T cell receptors
- Each t cell is covered with thousdands of identical receptors,each is capable of binding a single antigen
- Nonspecific immunity
- general barriers to infection, things related to general ability to repel infection
- soap barrier
- chemical, kills many bacteria
- Isopycnic density gradient centrifugation
- separate by isopycnic point (buoyant density)
- ICAM-I
- Intercellular adhesion molecule-I, rhinovirus receptor
- Virus Classification
- 1. Nucleic Acid Type 2. Nucleic Acid Strandedness 3.Sense of ss RNA 4. Structural Features 5. Host range
- rhinovirus
- type of picornavirus, common cold,
- transducing particle example
- Prohead of lambda phage
- Generalized transduction
- transfer of bacterial genes by phages
- B-cell and T-cell similarities
- Both have 2 types of proteins that each have constant/variable regions
- age barrier
- babies and elderly most susceptible
- lysozyme secretion barrier
- chemical, dissolves peptidoglycan
- Reasons for phage to end lysogeny
- 1. Drop in levels of Lambda repressor (UV light, chemicals) 2. Lambda repressor becomes less, xis, int, cro genes transcribed
- MHC (Major histocompatibility Complex) class I molecule
- bits of complex are placed on cell surface, recognized by t cell, and looked at to see what antigen was presented. If mature t cell ban bind to it, t cell reacts to set off an immune response
- DNA packaging
- into prohead- takes host and viral DNA
- Cro protein
- Inhibits production of transcription of lambda repressor
- good nutition barrier
- eat healthy
- Nucleocapsid
- Nucleic acid and capsid
- ssRNA- example
- influenza virus, ebola virus
- Non-enveloped virus
- Nucleocapsid
- Enveloped virus
- Necleocapsid, envelope
- Spike on orthomyxovirus that cuts sialic acid
- neuraminidase
- Multiplicity of Infection (MOI)
- Average amoun of virues added per cell
- Epstein-Barr virus
- mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma
- biological barriers
- living cells that actively kill passing bacteria
- Spanish flu
- flu epidemic in 1918, must have new vaccine each year
- CD28 receptors
- binds to macrophages
- opsonization
- helps neutrophils to bind to and engulf bacteria
- HIV
- type of retrovirus, +ssRNA
- Phage Beta
- Encodes for diptheria toxin during lysogenic conversion
- 95%
- of immature t cells die, leaving ONLY those t cells that gind to antigens not found in the body
- Virus:Poliovirus
- Receptor:PVR
- Purification Methods
- 1. Differential Centrifugation 2. Density gradient centrifugation 3. Isopycnic density gradient centrifugation 4. rate zonal gradient centrifugation
- prostaglandin
- once capillaries are stimulated, stimulates nerve cells to send a pain signal to brain
- DNA-dependent DNA polymerase
- used by normal cellular DNA replication
- Beta chain splices these regions
- V,D, J
- Picornavirus
- Family of viruses, +ssRNA
- DNA concatemer
- long continuous DNA molecule that contains many copies of same DNA sequence
- Example of generalized transduction for E. coli
- Phage 1
- Specialized transduction
- Only specific portion of bacterial genome is transferred
- mucosa barrier
- on internal surfaces exposed to bacteria- the intestines, lungs, reproductive tracts
- Protoplast
- Cell with no cell wall, used to study uptake of viruses
- Lytic life cycle
- Lyse host cells, release progeny virions
- Papillomavirus
- HPV- cervical cancer
- methods of nonspecific immunity
- healthy, nutrition, age-babies and elderly most susceptible, fever-higher body temp kills some bacteria and slows some viral replication, genetic factors
- types of capsomer
- pentamer, hexamer
- temperate phages 2 options
- 1. lytic cycle 2. lysogenic cycle
- RecA
- protein that can interact with lambda repressor if damaged, causing to cleave itself in induction
- disulfide bond
- how alpha and beta chains are linked together
- CD4
- binding site for HIV receptor on helper t-cells
- phage
- shortened term for bacteriophage
- chemical barriers
- prevent infection from entering body
- Virus: Rhinovirus
- Receptor: ICAMs
- Of Tc cells CD8 binds to MHC Class I and tcell receptor binds to antigen while tc cells are activated by IL2, cells will secrete proteins that induce: (3)
- 1. slow viral replication (interferon) 2. Die more accurately, commit suicide (tumor necrosis Factor) 3. Lyse (perforin)
- late mRNA
- structural proteins required for assembly, lysis, and release
- Orthomyxovirus
- Influenza virus
- phiX174 Virus
- + ssDNA virus
- Cytoplasm
- Translation takes place
- Hemagglutinin
- Antigenic glycoprotein on influenza virus that binds virus to cell
- Virus Titer
- Virus Concentration
- Reaction to a protein foun on the surface of flial cells, which insulate the electrical connections of our nerves
- Multiple Sclerosis
- icosahedral asymmetric unit
- containing 3-protein subunits
- Salmonella during lysogenic conversion
- lipopolysaccharide structure is modified
- CD4 receptros
- bind to MHC class II molecules
- lysogen
- Infected bacterial host
- Bone marrow
- where helper cells are born, but mature elsewhere
- Th1 cells
- contain CD28 and CD4 receptros, send out an alarm signal, interleukin 2 (IL 2)
- Structural studyies (3)
- 1. electron microscopy 2. electron tomography 3. x-ray crystallography
- hydroxymethyl-cytosine (HMC)
- modifies cytosine
- Mutualism
- Relationship that benefits both creatures
- dsRNA example
- Reovirus, rotavirus, blue tongue virus
- lyssaviruses
- include bullet-shaped Rabies vrius, enveloped,
- capsomer
- ring-shaped unit made of 5 or 6 proteins
- apoptosis
- Programmed cell death
- replicative form
- +/- DNA
- bradykinin
- alarm signal when tissue/cells are damaged
- early mRNA
- creates proteins/enzymes involved in phage DNA synthesis
- Spike on orthomyxovirus that binds to receptor sialic cid
- Haemagglutinin
- autoimmune disease
- a t cell that reacts with known antigen manages to survive in body
- Virus: HIV
- Receptor:CD4 on t-helper cells, macrophages, receptor sites CXCR-4 or CCR5
- Phage T4 life cycle
- Attachment, Penetration, Insertion, Transcription early mRNA, Replication phage DNA, Transcription late mRNA, Assembly, Lysis
- Spike
- peplomer-glycoprotein spike on capsid or envelope. only bind to receptors with host specificity/infectivity
- Bacterial LPS
- binds to complement protein C3b
- retrovirus
- +ssRNA virus
- neutrophils
- white blood cells that pass by in the bloodstream, roll along surface of selectin-expressing cells, and crawl between capillary cells to infected tissue and phagocytose everything they find
- Clonal selection
- If t cell receptor can bind to presented antigen, then tcell is activated and divides rapidly
- "cos" sites
- cohesive ends, DNA of phage Lambda contains 12 base ss cos sites
- Parasitism
- Benefits one creature at expense of other
- t cells that have CD8 receptors that bind specifially to MHC class I molecules so that cells can examine antigens presented by any cell
- Tc (cytotoxic t cells)
- superinfection
- lysogenic bacteria is immune, lambda phage blocks any new lambda phage
- Calicivirus
- +RNA
- budding
- method eukaryotic viruses use to escape host cell by using host plasma membrane
- Rate zonal gradient centrifugation
- Counteract increasing force so particles move in proportion with time in field
- Lambda repressor
- blocks transcription of Cro gene, other genes needed for lytic cycle
- sialic acid
- binding site for haemagglutinin, cut by neuraminidase
- ligase
- breaks sealed phage Lambda in complementary base-pairing
- Receptor-mediated endocytosis
- cytoplasm folds inwards, budding vesicles
- Alpha and Beta chains
- proteins embedded in plasma membrane of t cell
- human cytomegalovirus
- Birth defects, blindness
- washing barrier
- removes microbes
- Proteins involved in Cell lysis and phage release
- T4 Lysozyme, Holin
- latency
- ability to hide in host cell without reproducing
- Interferon
- causes slow viral replication
- skin barrier
- a dry surface
- phagocytosis
- engulfing solid particles by cell membrane to form internal phagosome (vacuole)
- Gag, Pol, Env
- polypeptides
- CD155
- poliovirus receptor
- Mimivirus
- Giant virus that attacks amoeba
- Virus: Hepatitis A
- Receptor: Alpha 2-macroglobulin
- poliomyelitis
- condition caused by poliovirus
- Satellite Tobacco masaic virus
- icosahedral virus
- Human T-cell lymphotropic viruses
- (retrovirus) leukemia
- filoviruses
- ebola virus, causes hemorrhagic fever, membrane envelope with helical symmetry
- restriction endonucleases
- restriction enzyme, cuts dsDNA restriction sites
- Hemagglutination assay
- Viruses with hemagglutinin on surface
- Virus: Influenza A
- Receptor:Sialic acid glycoprotein
- microtubule
- once endosome lyses, microtubules omove particles towards nuclear pore
- Hepatitis C virus
- +RNA
- 4 types of cells in specific immune system
- 1. Helper T cells 2. cytotoxic T cells 3. B cells 4. Macrophages
- Virus: Rotavirus
- Receptor: a2b1, a4b1
- Gag
- protein for making capsid proteins
- Tumor necrosis Factor
- Causes virus to die, commit suicide
- Ways Eukaryotic virus may enter a cell
- 1. Enveloped- fusing with plasma membrane 2. Enveloped- endocytosis 3. non-enveloped- endocytosis
- poliovirus
- type of pucornavirus, polio
- Types of capsid symmetry
- Helical, Icosahedral
- complement
- C3b
- Eukaryotic virus
- Virus that binds to receptors on surface (proteins, glycoproteins
- Special properties of viruses
- 1. Acellular 2. DNA or RNA, not both 3. Can't reproduce independently
- Inactivated virus vaccine
- Using heat/chemical treated virus, dangerous to produce, must be 100% inactivated, multiple vaccinations
- dsDNA virus process
- 1. use DNA genome as template for mRNA synthesis 2. mRNA translated to produce viral proteins 3. use host RNA polymerase
- transducing phage example
- lambda phage
- B-cell receptors
- antibodies, immunoglobulins
- operator
- binded to by lambda repressor or cro protein
- T4 phage receptor
- E. coli lipopolysaccharide
- Malaria
- Parasite of medical important, responsible for many deaths
- fever barrier
- high body temp kills some bacteria and slows some viral replication, some bacterial components such as lipopolysaccharide induce fever
- Norwalk virus
- +RNA
- Plaque forming unit (PFU)
- measure of particles capable of forming plaque in a limited volume
- stomach acid, liver bile, intestinal enzymes
- chemical, kill bacteria
- Example of generalized transduction for Salmonella
- Phage P22
- smallpox/cowpox
- caused by the poxvirus
- Burst size
- Number of viruses produced per infected cell
- Virulent phage
- Pathogenic phage, uses lytic life cycle
- lysogeny
- Integration of viral genome with host genome in a relationship
- Physical barriers
- any block that precents access to the inside of the body
- clonal deletion
- T cells tracel to thymus gland, where they are presented with all antigens present in human body. If immature t cell can bind to antigen, it undergoes apoptosis
- dead skin barrier
- sloughs off regularly
- DNA-dependent RNA polymerase
- used by transcription
- Virus: Epstein-Barr
- Receptor: C3d on human B lymphocytes
- MHC class II proteins
- present on surface of macrophages and Bcells only
- Envelope
- Lipid bilayer, spikes
- Herpes simplex virus 1 (HSV-1)
- oral herpes, cold sores
- T-cell receptors are made of two types of proteins
- Alpha (light) chain and Beta (heavy) chain
- Endosme
- Fuses with enveloped viruses/endocytosed viruses
- cell/tissue damage
- burst dead cells cause neighboring cells to produce an alarm signal-bradykinin
- prophage
- form of phage that remains in host integrated into chromosome
- Recombinant vector
- Genetically modified such as adenovirus that carry additional gene encoding antigens from virulent viruses. Presented to immune system to induce immunity.
- histamine
- secreated by mast cells, binds to capillary cells and causes them to change shape slightly to permit lique from blood stream to enter tissue
- variable region in t cell
- different amino acid sequence in every t cell
- Measles virus
- -RNA
- herpesviridae
- largest family of human/animal viruses. linear dsDNA
- Lysogenic cycle
- Remains in host without destroying it
- bradykinin
- binds to mast cells near capillaries, causes them to degranulate to release amounts of histamine
- Adenovirus
- Type of herpesvirus, non-enveloped linear dsDNA- uses endocytosis
- Virus: Herpes Type 1
- Receptor:Heparan sulfate
- Corynebacterium diphtheriae
- produces diptheria toxin in lysogenic conversion
- constant region in t cell
- same amino acid sequence
- Rolling circle
- Mechanism using +ssDNA to create ds+/- DNA
- att site
- where lambda genome is integrated into host genome
- tRNA (while creaing DNA)
- used as primer for reverse transcriptase
- Virion
- Infectious virus as it exists outside of host cell
- Virus
- Acellular infectious agent
- Arterivirus
- +RNA
- ds DNA example
- herpesvirus, bacteriophages
- Plaque
- Bacteriophage viruses replicate and spread, generating cell destruction
- Env
- protein for making envelope spikes
- lipopolysaccharide
- binding site for T4 phage
- length of urethra
- slows bladder infection
- Temperate phage
- has two options for reproduction, lytic or lysogenic life cycle
- Order, Family, Subfamily, genus and species
- -virales, -viridae, -virinae, virus
- Herpes simplex virus 2 (HSV-2)
- genital herpes
- Poliovirus
- ss RNA+, simplest significant virus
- extravasation
- infected tissue
- inflammation
- body's general response to localized infection
- Influenza virus
- -RNA
- enzyme E
- blocks synthesis of host cell peptidoglycan, causes to lyse and release
- -stranded RNA virus
- Orthomyxoviruses
- Eukaryotic compartments
- Cell wall, nucleus, nuclear pore, endoplasmic reticulum, golgi apparatus, endosome
- ssDNA example
- parvovirus
- Protomer
- Smallest subunit in viral capsid
- Differential/density gradient centrifugation
- Purify by size, viruses are smaller than cells, larger than proteins
- HIV protease,
- viral protease that cleaves polypeptides Env, Gag, Pol into individual proteins
- indigenous microbes
- biology barrier, in the intestine and reproductive tracts, and on skin, kill other bacteria by secreting bacteriocins, eating available food, and taking up places to which parasites could attach
- Icosahedral virus example
- Adenovirus
- Immune response
- If mature t cell can bind to antigen, t cell sets off alarm
- ssRNA+ example
- Poliovirus, rhinovirus
- genetic factor barrier
- unknown aspects of persons genetic background make them more or less susceptible to particular diseases
- exons
- consecutive pieces, referring to the variable regions in t cells
- electron microshopy/tomography
- Can see shape of virus particles, not much detail
- DNA vaccine
- Take genes from viruses and inject them into host to produce viral proteins that cannot produce the virus, safe, multiple vaccinations
- Bacteriophage
- Virus that infects bacteria
- Nucleus
- Replication and transciption take place
- cI gene
- produces Lambda repressor
- acid secreted in female reproductive tract barrier
- kills bacteria, neutralization of this acid can cause infections
- Virus Life Cycle
- 1.Attachment 2.Viral Entry 3.Synthesis 4.Assembly 5. Release
- Plasmodium falciparum/Plasmodium vivax
- Viruses account for Malaria deaths
- T4 head
- DNA packed
- rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis
- autoimmune diseases
- Virus: Viccinia
- Receptor: epidermal growth factor
- Interleukin 2 (IL 2)
- alarm signal, one needed to activate cytotoxic T cells
- Plaque assay
- Indirect measure of concentration of viruses
- Virus Cultivation methods
- 1. Animal host cell. 2. Embryonated chicken egg 3. Tissue/cell culture
- Anopheles
- mosquito that carries Malaria virus in saliva
- Virus: Measles
- Receptor: CD46
- reverse transcriptase
- creates DNA from RNA-also carries ribonuclease Hwhich degrades RNA
- clathrin-coated vesicle
- what adenoviruses use to internalize into host
- sloughing off of mucous barrier
- from mucosal surfaces
- X-ray crystallography
- Challenging method of producing atomic structures of virus
- Endocytosis
- Engulfment by receptor-mediated sites to form coated vesicles
- pentamer
- 5-subunit capsomer
- Symbiosis
- Living together
- Virus: Adenovirus
- Receptor: Coxsackie (CAR)
- provirus
- transcribed to make mRNA and to provide more +ssRNA for packaging
- T4 long tail fiber
- binds to receptor
- aid in phagocytosing
- C3b receptors on neutrophil surface
- Viral assays
- 1. Electron microscope 2. Hemagglutination assay 3. plaque assay
- Orthomyxoviridae
- family of enveloped, helical, -ssRNA
- hexamer
- 6-unit capsomer
- Virus:Rabies
- Receptor:Acetylcholine
- reovirus
- non-enveloped, icosahedral, dsRNA genome, use endocytosis
- selectin
- attract neutrophils
- ribonuclease H
- degrades RNA
- peforin
- Causes virus to lyse
- Alpha chain splices these regions
- V, J together
- immobile phagocytes
- biological, of the reticuloendothelial system phagocytose bacteria
- Kaposi's sarcoma-associated herpescirus
- Kaposi's sarcoma
- example of specialized transduction
- lambda phage
- Phage T4
- classic virulent phage, infects E. coli
- Commensalism
- Benefits one creature, neither helps nor harms other
- T4 Lysozyme
- Attacks peptidoglycan of E. coli cell wall
- +ssRNA with DNA steps
- retrovirus (HIV)
- health barrier
- stay healthy
- Holin
- Creates holes in E. coli plasma so lysozyme can get from cytoplasm to cell wall
- RNA-dependent RNA polymerase
- viruses use to encode
- Cytopathic effect
- Causes red blod cells to clot, leads to creation of plaque
- cI Promoter (Prm)
- enhances own synthesis of lambda repressor
- Attenuated virus vaccine
- Virus modified genetically to make a cirus that replicates poorly in us, only one vaccination
- cell shape change
- histamine binds to capillary cells
- Icosahedron
- Most efficient way to make closed shell using little proteins, largest size for encapsidation 12 vertices, 20 faces, 30 edges, 60 units
- Receptor
- Specific surface structures on host to which viruses attach
- + RNA viruses
- Genome utilized like mRNA, produce single proteins needed for replication
- foreign antigens
- antigens not normally found in the human body
- poxvirus
- largest known animal virus- dsDNA- complex icosahedral structure
- induction
- conditions in cell cause prophage to initiate synthesis of new phage particles, how a phage gets out of lysogeny
- Phage Lambda
- Icosahedral temperate phage dsDNA
- adenovirus
- non-enveloped, icosahedral, linear dsDNA
- Vericella-zoster virus
- Chicken pox, shingles
- Methods of reproduction for bacteriophages
- Lytic, lysogenic
- - RNA viruses
- Must have genome copied by RNA polymerase to make + RNA
- Cariola cirus
- Causes smallpox
- coxsackie adenovirus receptor (CAR)
- receptor site for adenovirus
- Antigens
- Proteins or pieces of proteins that can be bound by receptor proteins on teh surfaces of the T and B cells
- Lipid Bilayer
- Sensitive to desiccation, heat, detergents
- Pol
- reverse transcriptase plus integrase
- lysogenic conversion
- changes in phenotype induced by lysogeny
- Reverse transcription
- makes ds DNA from ssDNA
- oil on skin barrier
- chemical barrier