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113 Cards in this Set
- Front
- Back
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What does a virus contain? |
DNA or RNA. Protein coat Some have enclosed envelopes Some have spikes |
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What does a virus infect? |
Most viruses infect only specific types of cells in one host species
Humans and bacteria |
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What is host range determined by? |
The viruses requirements for its specific attachment to the host cell & availability within the potential host of cellular factors required for viral multiplication |
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Why are viruses NOT considered living organisms ? |
Because they have to be grown in living cells |
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How are bacteriophages cultured? |
They are grown on solid media. They form plaques on a lawn of bacteria. |
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How ate animal viruses cultured? |
In cell cultures and must be grown in loving animals or embroynated eggs |
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What is a viral species? |
A group that share the same ecological niche and have the same genetic info. |
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What is an oncogene |
Cancer causing alterations to cellular DNA affects parts of the genome |
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Latent viral infection |
Virus remains asymptomatic in host cell for long periods of time Example: cold sores, shingles |
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Persistent viral infection |
Disease processes occur over a long period; generally fatal. Example,: measles virus |
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Prion |
Infectious protein |
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Viroids |
Infectious RNA |
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Virus |
DNA or RNA + protein coat |
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Viral size |
Range from 20 to 1000 nm in length |
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What is a capsid? |
The protein coat surrounding the nucleic acid of a virus |
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Capsid of virus |
Some viruses are enclosed by an envelope consisting of lipids, proteins, and carbohydrates |
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Name a virus that causes plant disease |
Viroids |
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Difference between bacterium and a virus? |
A virus has to live in a host cell to live. Viruses are much smaller than bacteria. While most bacteria is harmless, most viruses cause diseases |
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Steps of lytic cycle |
Attachment Penetration Biosynthesis Maturation Release |
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What is a pathogen? |
Disease causing microorganisms |
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Etiology |
Cause of disease |
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Infection |
The invasion or colonization of thr body by pathogenic microorganisms |
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Disease |
Occurs when an infection results in any change from a state of health. Disease is an abnormal state in which part of all the body is not properly adjusted or incapable of performing normal function. |
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Normal microbiota |
Microorganisms that establish more or less permanent residence but don't produce disease under normal conditions. |
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Transient microbiota |
May be present for a few days, weeks, or months then disappear. Not throughout body localized. |
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Commensalism |
Organism benefits & the other unaffected. Example: corynebacteria. |
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Mutualism |
Both organism benefit Example: large intestine with bacteria. |
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Parasitim |
1 organism benefits at the expense of the other. |
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Opportunistic |
Ordinarily don't cause disease in their normal habitat in a healthy person but may do in a different environment |
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Communicable disease |
Any disease that spreads from 1 host to another, either directly or indirectly |
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Noncommunicable disease |
Is not spread from 1 host to another |
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Pattern of disease |
Incubation period- initial infection & show symptoms Prodromal period- early, mild symptoms of disease like aches and malaise Period of illness Period of decline Period of convalescene- regain strength & back to the health before disease |
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Reservoir of infection |
A source that can be either living organism or an inanimate object that provides a pathogen with adequate conditions for survival & multiplication & an opportunity for transmission. |
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Four methods of disease transmission |
Contact transmission: person to person transmission Indirect transmission: occurs when the agent of disease is transmitted from its reservoir to a susceptible host by means of a non living object Droplet: microbes are spread in droplets nuclei that travel short distances. Ex: coughing, sneezing, talking Vehicle: transmission of disease agents by medium: water, food, & air |
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Mechanical |
passive transport of the pathogens on insects feet or other body parts |
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Nonsocomial infections |
Doesn't show evidence of present or incubating at time of admission to hospital, it is aquire through hospital stay |
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Composied host |
One whose resistance to infection is impaired by disease, therapy, or burns. |
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Function of CDC |
Conducts & supports health promotion, prevention, and preparedness activities in u.s. with goal of improving health |
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Fungi |
Eukaryotic Most decomposers Aerobic or facutalievly aerobic |
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Mycology |
Study of fungi |
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Molds |
Consist of hyphae; a mass of hypae is a mycelium |
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Yeast |
Unicellular Fission yeast divides symmetrically Budding yeast divide asymmetrically |
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Dimorphism |
Pathogenic dimorphic fungi are yeast like at 37 and mold like at 25 |
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Systemic mycoses |
Deep within body |
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Subcantenous mycoses |
Beneath skin |
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Cutaneous mycoses |
Affect skin, hair, nails |
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Superficial mycoses |
Localized hair shafts |
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Opportunistic mycoses |
Caused by normal microbiota or fungi that are normal |
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Asexual spores |
Sporangiospore Condos pore Bladtocondium Chlamdyospore |
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Sexual reproduction |
Plasmoglamy Karogamy & nuclei fuse Diploid nucleus produces haploid nuclei. Meiosis |
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Zygore |
Fusion of haploid cells produces one zygospore |
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Ascospore |
Formed in a sac |
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Basidiospores |
Formed externally on a pedestal |
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Conjugation fungi |
Coenocytic produce sporangiospore and zygospores |
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Basiomycota |
Produces basidiospores & sometimes condiospores |
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Anamorph |
Telemorphic fungi Produce asexual and sexual |
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Anamorphic fungi |
Produce sexual only Sporothrix Pencillium Stachybotrys, coccidioides, pneumocystis Candida albicans |
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Lichens |
Mutualistic combination of an alga & fungus Alga produce & secrete carbohydrates, fungus provides hold fast |
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3 types of lichens |
Fruiticose, foliose, crustose |
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The algae |
Eukaryotic Unicellular, filamentous, or multicellular Most are photoautrophs |
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Rhodophyta |
Red algae Cellulose cell walls Most multicellular Stores glucose polymer Harvested for agar |
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Phacophyta |
Brown algae Cellulose & alginic acid cell walls Multicellular Chlorophyll a & c xanthophylls Store carbohydrates Harvested for algin |
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Chlorophyta |
Green algae Cellulose cell walls Unicellular or multicellular Stores glucose polymer Gave rise to plants |
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Bacillariophyta |
Diatoms Pectin & silica cell walls Unicellular Stores oil Fossilized diatoma formed oil Produce domoic acid |
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Multiplication cycle of animal viruses |
Attachment- viruses attach to cell membrane Penetration - by endocytosis or fusion Uncoating - by viral or host enzymes Biosynthesis - production of nucleic acids & proteins Maturation - nucleic acid and capsid proteins assemble Release - by budding or rupture |
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Human microbe interactions |
Can be beneficial or harmful |
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Beneficial interactions |
Nutrient recycling, food production, waste - water treatment, antibiotic production |
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Example of of beneficial interaction |
Mutualistic relationship between a human & their normal microbiota. Without their presence, we likely could not survive. |
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Disease causing microbes |
Pathogens |
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Harmful interactions |
Food spoilage, decomposition of valuable commodities, and disease |
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Pathogenic microorganisms |
Special properties that allow them to invade the human body and produce toxins |
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Infections |
Not all infections are disease causing. To be a disease, damage to the host tissue or function must occur |
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Pattern of infection |
1.Exposure: of host to microbe 2.Adherence: the microbe attaches to the skin or mucous membrane of host 3.Invasion: microbe passes through epithelium 4.Colonization & growth: increase in microbial metabolism and population numbers 5. Toxicity: toxic effects 6. Tissue damage: disease |
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Predisposing factor |
One that makes the body more susceptible to disease or alters the course of a disease |
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Reservoirs of infection |
A disease or are carriers of pathogenic microorganisms |
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Transmission of infection |
May occur soilborne, airborne, arthropodborne, and contact |
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Nonsocomial infection |
5-15% of all hospitalized patients acquire nonsocomial infection |
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Compromised host |
Such as patients with butns, surgical wounds, and suppressed immune systems are the most susceptible to nosocomial infections |
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How microbes enter a host |
Many microorganisms can penetration mucous membranes of the conjunctiva & the respiratory, gastrointestinal, & urogenital tracts |
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How microbes enter a host |
The respiratory tract most common portal of entry |
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Microorganisms enter gastrointestinal tract |
Through food, water, and contaminated fingers |
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How microbes infection enter host |
Some microbes can gain access to tissues by inoculation through skin & mucous membranes in bites injections, or wounds |
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Exotoxins |
Produced by microorganisms & released into the surrounding medium medium |
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Exotoxins |
Produce the disease symptoms |
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Enterotoxins |
Are exotoxins that specifically target the gastrointestinal tract |
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Endotoxins |
Toxins stored within the pathogen, usually in the cell wall. When the pathogen cell is ruptured, usually by death of pathogenic cell, the endotoxins are released |
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Resistance |
The ability to ward off disease through body defense |
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Lack of resistance |
Susceptibility |
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Nonspecific resistance |
Refers to all body defenses that protect the body against any kind of pathogen |
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Specific resistance (immunity) |
Refers to defenses (antibodies) against specific microorganisms |
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Resistance to microbes |
The stucture of intact skin & the waterproof protein keratin provides resistance |
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The lacrimal apparatus |
Protects the eye from irritating substances and microorganisms |
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Saliva |
Washes microorganisms from teeth & gums. |
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Mucous |
Traps many microorganisms that enter the respiratory and gastrointestinal tracts, in the lower respiratory tract, the cilia escalator mucous up and out |
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Normal microbiota |
Occupy most available niches, preventing transient pathogens from establishing infections |
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Inflammation |
Bodily response to cell; it is characterized by redness, pain, heat, swelling, and sometimes the loss of function |
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Fibrin clots |
Help to isolate the infection. Sometimes this favors the pathogen because more host tissue will be damaged |
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Fever |
An abnormally high body temp produced in response to a bacterial or virus infection |
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Continuous fever |
The fever elevates above normal and remains constant until breaking |
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Remittent |
The fever fluctuates between very high & low but never at normal until breaks |
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Intermittent fever |
The fever fluctuates between high & normal before it breaks |
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Immunity |
The ability of the body to specifically counteract foreign substances or organisms called antigen |
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Immunity |
Results from the production of specialized lymphocytes and antibodies |
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An antigen |
A chemical substance that causes the body to produce specific antibodies or sensitized T cells. |
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Antigens |
Foreign substances; they are not part of the body's chemistry |
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Antigens |
May be components of invading microorganisms |
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Immunity |
May develop or acquire it after birth |
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Naturally acquired immunity |
This type of immunity may be long lasting |
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Antibodies |
Transferred from a mother to a ferris or to a newborn on breast milk results in naturally acquired passive immunity Last a few months |
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Artificial acquired immunity |
Immunity resulting in vaccinations. Can be long lasting |
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Antiserum |
Serum contain antibodies |
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Humoral immunity |
Antibodies produced by B cells, is in body fluids |
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Cell mediated immunity |
Due to certain types if lymphocytes |
