microbiology final Flashcards
what is bioremediation
it’s when bacteria is used to clean up environmental pollutants
what is true about archea
Some archeae have pseudopeptidogylcan in their cell walls.
describe the steps of the lytic cycle in order of a typtical bacteriophage
- attachment
- genome entry
- synthesis
- assembly
5.release
attachment is when a phage attaches to a specific receptor
genome entry tail contracts and dna is injected into the bacterail cell
synthesis is when phage genome is transcribed proteins replicated phage DNA is transcribed
assembly phage components are assembled into mature viron particles
what are not arthropods
flukes
arthropods are lice fleas mosquitos ticks
what is a characteristic of many protozoa
the ability to exist as either a trophozite or a cyst
what is a true statement regarding normal microbiota
Normal microbiota protect us from disease by competing with pathogenic bacteria.
name three ways fungi can cause illness in humans
hypersentivity a person has allergic reactions to fungal components
intoxication fungus that produces a toxin that is ingested
injection fungus grows on body as a mycosis
what are major producers of oxygen
algae
A patient’s throat swab yields organisms that appear as long chains of round cells under light microscope. Given this information, it is possible that the organism is:
Streptococcus pyogenes
genetic exchange in segmented viruses that allows a zoonotic virus to infect humans is an example
antigenic shift.
what are 3 reasons why liposaccharides are important
large amounts of lipid a may cause fetal effects
small amounts of lipid A alert the immune system to present bacteria
o antigen can be used to distinguish between different bacteria
difference between the defintion of prokaryote vs eukaryote
eukaryote An organism characterized by having cells containing membrane-bound DNA
prokaryote An organism characterized by having a cell lacking a membrane-bound nucleus.
define prion
virus
viroid
prion an infectious agent consisting of only protein.
virus An infectious agent containing protein, nucleic acids, and sometimes a lipid membrane.
viroid An infectious agent consisting of only RNA.
steps on which prion propagates
Both normal (PrPc) and abnormal
(PrPsc) proteins are present
PrPsc interacts with PrPc.
PrPc is converted
into PrPsc.
Conversion continues and
PrPsc accumulate
define domain and spontaneous generation
domain is the highest level of classification
spontaneous generation a hypothesis concerning life arising from dead organic compounds.
A modified Gram-stain procedure uses Bismark brown as a counterstain instead of safranin. In this case, Gram-negative cells would appear _____, while Gram-positive cells would appear _____.
brown and gram positive purple,
what is true about filamentous phages
only infect E. coli that have pili.
what virsuses have a higher mutation rate
rna genome
What is a definitive host in the life cycle of a parasite
an organism in which sexual reproduction or the adult form of a parasite occur
Electron microscopes differ from light microscopes in that
magnification is higher.
what are animal viruses
Rabies virus, which can be transmitted from animals to humans, is classified as a(n) ______ virus.
Entry of bacteriophages and animal viruses into host cells
differs because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid.
Lichens may be an association of
algae and fungi.
lease select the CORRECT definition for primary endosymbiosis.
A non-photosynthetic eukaryotic cell engulfs a cyanobacterium, which becomes a chloroplast.
How did John Tyndall’s work help to explain why some scientists had difficulty reproducing Pasteur’s work proving that life comes from pre-existing life
He demonstrated that some broths require greater boiling times because they contain heat-resistant bacterial forms.
Correct
You do a chemical analysis of three bacterial samples. In one (sample A), you find phospholipids, peptidoglycan, O antigen and lipid A. In the second (sample B) you find peptidoglycan, phospholipids and teichoic acids. In the third (sample C) you find phospholipids but no peptidoglycan. Select the TRUE statement
Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - Mycoplas
what are the bacterial components increase the organism’s effectiveness as a pathogen ( disease causing organism ) ?
lipopolysaccheride
capsule
fimbrae
immigration from ireland to the united states occured in high numbers due to an infection of potatoes by
water molds
the use of oil with certain high power objective lens increases
resolution
After beta phage infects Corynebacterium diphtheriae and integrates its DNA into the host genome, the bacterium is capable of causing the disease diphtheria. Which term best describes this phenomenon?
lysogenic conversion
describe the eukaryotic group algae
mostly aquatic
basis of food chain
cell walls with cellulose
contain chlorophyll
describe the eukaryotic group fungi
cell wall with chitin
may be dimporpic
used to make beer and wine
saphrophytic
describe the eukaryotic group helminths
flatworms
asorb nutrients parastically
describe the eukaryotic group protozoa
plasmodium
calcium carbonate shell
classified by locomotion
may lack mitochondria
which is one of the greatest causes of human deaths through time
plasmodium species
where the idea of spontaneous generation come from
living organisms could spontaneously arise from non-living material.
what is the definition of acute infection
Infection in which a virus multiplies rapidly and spreads in the host.
what is the defintion of generalized vs specialized transduction
generalized Transduction resulting from a packaging error.
specialized transduction which results in an error in excision of a prophage
what is the difference between the the temperate and virulent phage
temperate phage is able to incorporate its genome into the host chromosome
virulent phage lyses bacterial host when completing its life cycle
what is robert koch known for
devised postulates for establishing causative relationship between a microbe and a disease
what is the importance of chrisitian gram
Developed staining method for differentiating between groups of bacteria.
whaf did walter and fanny hesse do
Introduced agar-agar as a solidifying gel in culture media
what did joesph lister do?
Published the first work on antiseptic surgery.
what did paul erich accomplish
Developed the first chemotherapeutic agent, for treating syphilis.
what did louis pasteur do ?
Developed a microbial control technique for preserving food and liquid.
a high therapeutic index is
less toxic to the patient
the difference betweeen identifcation vs classification
identification is the process of characterizing an isolate to determine the group which it belons
classifications is arranging organisms into similar or related groups of study
define nomenclature and phylogeny
nomenclature is the system of assinging names to organism
phylogeny is the evolution of organsims
classify medical indtruments as critcal semicritical or noncritical
critical- scalpel needles venous catherer
semi critcal - gastrointestinal endoscope
endotracheal tube
thermometer
noncritical - stethoscope and blood pressure cuff
describe metagenomics
total microbial genomes in an environment.
if you see media that changes color as a result of biochemical activty of growing bacteria what does it mean
usually contains a ph indicator
Production of extracellular polymeric substances (EPS) enables bacteria to
form biofilms
Which type of ribosomal RNA is most often used in taxonomy?
16S
define preservation and sterilization
sterilization is the destruction of all microbial life
preservation slows down the microbial growth but does not reduce the number of exostong microbes
disinfection vs decontamination
decontamination Mechanical removal of most microbes from living or inanimate surfaces
disinfection Reduction of most microbial life on inanimate surfaces
decribe the differrent strains of prokaryotes
biochemical typing
phage typing
molecular typing
serological typing
antibiograms
biochemical typing relies on unique metabolic activities of the mocrobe
serological typing is the use of the specific antibodies to detect unique antigens on the microbe
molecular typing trlies on detecting specific differences in the microbe DNA or DNA patterns
phage typing testing relies on the use of specific bacteriophages to detect a partcular mobile strain
antibiograms testing relies on antibiotic susceptiblity patterns generated by specific microbes
is this a mismatched statement yes
Alexander Fleming - successfully purified large amounts of penicillin from the mold Penicillium.
define chemical preservatives
Must be non-toxic. Weak organic acids such as benzoic or sorbic acids often used. Nitrate and nitrite can also be used to inhibit germination of endospores of C. botulinum.
define low temperature storage
Slows or stops critical enzyme reactions in some (but not all) microorganisms.
what does it mean to reduce the water availability
Additions of sugar or salt, or subjecting the food to a high vacuum environment.
define microwaves
Doesn’t affect microorganisms directly, but can generate heat in fluids which can indirectly kill microbes.
define ultraviolet radiation
Not very penetrating radiation. Easily stopped by interfering materials. Works by producing thymine dimers in DNA strands. Most effective at close range and with long duration of exposure.
define ionizing radiation
High energy radiation that directly destroys DNA and damages cytoplasmic membranes. It can also cause indirect damage by producing reactive oxygen species (ROS).
how can horizontal gene transfer occur
it can occur via conjugation
explain this term steam under pressure dealing with the use of moist heat to control microbial growth
Requires use of an autoclave. To sterilize, temperature must reach 121°C for a minimum of 15 minutes.
define pasteurization
Heat applied to beverages to prevent spoilage and kill pathogens. High-temperature-short-time protocols include holding liquids at 72°C for 15 sec. Does not sterilize.
define commercial clanning
Uses an autoclave called a retort to destroy the endospores of Clostridium botulinum. It will not destroy the endospores of some thermophiles.
A halophilic, aerobic mesophile has a generation time of 20 minutes. You place 1x104 of these organisms on an appropriate solid medium, and incubate the plate for 100 minutes. Select the FALSE statement
After incubation, a colony on the plate contains 5 x 104 cells.
Identify two advantages of using sequence analysis of ribosomal components in classification.
Ribosomal genes are present in all organisms - they are essential for survival, so rarely mutate; thus, some of the sequences will still be similar even in groups of organisms that diverged long agoRibosomal genes are present in all organisms - they are essential for survival, so rarely mutate; thus, some of the sequences will still be similar even in groups of organisms that diverged long ago Correct
The ribosomal genes are not transferred horizontally, an event that would complicate an analysis of evolutionary relatedness.
Antibiotics that affect various strains of Gram-positive bacteria and various strains of Gram-negative bacteria are called
broad-spectrum.
The simplest technique for isolating bacteria is referred to as the
streak plate method
you are in charge of water quality for your city’s water treatment plant. Which is the most efficient and cheapest method of determining the number of viable (living) bacteria in the water coming out of your plant?
Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation.
In a rapidly multiplying bacterial population, cell numbers increase
logarithmically.
The decimal reduction time is the time it takes to kill 90% of a given bacterial population under certain conditions. If 90% of a population of 100,000 bacteria is killed in 10 minutes, how long would it take to reduce the population to 10 cells
40 minutes
When studying microbes, why is it important to separate mixed communities into individual pure cultures of the different species?
So we can understand the biochemical characteristics of one species without confusing it with another species.
Which of the following requires that cells be competent?
transformation
you are analyzing a bacterial genome. You find that the G-C content is 60%. However, in one part of the genome, the G-C content is 37%. What can you conclude?
the organism has a genomic island
In conjugation the donor cell is recognized by the presence of
an F plasmid.
phage typing
is used to distinguish bacterial strains.
Which of the following does not introduce DNA into a bacterial cell?
transcription
Which is the correct definition of selective toxicity?
A medication causing greater harm to a pathogen than to the host.
Why is autoclaving better than boiling for sterilizing microbiology equipment and media?
Autoclaves use pressurized steam, so can achieve a higher temperature than boiling water.
describe the domain bacteria
no introns
unicelluar usually with peptidoglycan cell walls
define the domain archaea
introns sometimes is present
unicellulae no peptidoglycan in cell wall
hydrocarbons cytoplasmic membrane
describe the domain eukarya
intrins are common
80S ribosomes
unicelluar or multicelluar
membrane bound nucleus
Explain how using a combination of two antimicrobial drugs helps prevent the development of spontaneously resistant mutants.
It is highly unlikely that the microbe might spontaneously develop two specific mutations to resist the effects of a pair of drugs. As such, even if one drug is resisted by the microbe, the second drug will eliminate the mutated microbe, thus preventing the development of spontaneously resistant mutants overall.
The clustered, regularly interspaced short palindromic repeats (CRISPR) system in bacterial cells has been called the “immune” system of bacteria. CRISPR protect bacteria from a repeat infection from the same phage because bacterial cells
integrate fragments from the phage DNA in their own chromosomes and target for destruction any DNA that contains the same fragments in the future.
desribe the germicide the halogen
chlorine chlorine dioxide iodine
common disinfectant which oxidizes proteins and other cell components
describe quarternary compounds
cationic detergent which can be safely used on food preparation surfaces
compound reacts with membranes to destroy many vegatative bacteria and enveloped viruses
these compounds are ineffective against mycobacteria naked viruses and pseudomonas species
define alcohols
ethanol or isopropanol
solutions can be used as antispecrtics or disinfect instruments without leaving a residue
aqueous solutions which can kill vegatative bacteria and fungi
describe phenolic compounds
carbolic acid and germicidal agent which can leave antimicrobial residue after use
what is quorum sensing
involves the production and monitoring of signaling molecules AND is used by bacteria to sense the density of cells within their population.
How do you think the scientists isolated L. methylaminiphilus from the sediments, knowing that a single gram of soil may contain thousands of different species of bacteria?
enrichment cultures
how would classify L methylaminiphulus with regards to pH
neutrophile
How would you classify L. methylaminiphilus with regards to temperature requirements?
psychrotroph
Consider the growth of L. methylaminiphilus on methylamine. How would you classify this species based on its metabolism
chemoorganoheteotroph
The antimicrobials produced by some molds and bacteria are generally called
antibiotics
what are sterilants
germicides known as sterilants can destroy all microbes including both bacterial endospores and all types of viruses
what are high level disinfectants
high level disinfectants destroy all viruses and vegetative cells but will not kill endospores
describe intermediate level disinfectants
they destroy vegative cells and some but not all viruses. they are unable to kill endospores even when when used for for a proplonged period of time
describe ow level disinfectants
low level disinfectants kill vegative cells except for mycobacteria and are unable to destroy nonenveloped endospores
Members of this group of microbes can break down glycogen deposited in the vaginal lining in response to estrogen. This helps to drop the pH in the area, preventing infection
lactic acid bacteria
define ecology
Study of the interaction of organisms with each other and their environment
define population
organisms of the same type given in an environment
define community
All of the different organisms in a location
define ecosystem
Community of organisms and the non-living environment with which they interact
define biosphere
All of the ecosystems on Earth
define ecological niche
Role of an organism in a particular ecosystem
define microenvironment
Environment immediately surrounding an individual microbe
describe rhizobia
form a nodule that creates an endosymbiotic relationship between legume plants and the bacterial cells.
define match these soil organisms with their characteristics.
Azospirillum species Streptomyces species Bacillus species
Azospirillum species Fix nitrogen
bacillus species foem endospores
Streptomyces speciesProduce antibiotics
Place the layers that would exist in a microbial mat in the correct order from top to bottom layer.
A green layer filled with photosynthetic cyanobacteria.
A reddish-pink layer consisting of purple sulfur bacteria.
A black layer filled with sulfate-reducing obligate anaerobes.
Match the Clostridial species with the diseases they cause.
Clostridium tetani
Tetanus: a disease characterized by painful muscle spasms.
clostridum perifingers
Gas gangrene: a disease characterized by necrotic tissue and the production of gas.
clostridium difficule
Antibiotic-associated diarrheal disease.
clostridum botulinum
Botulism, a disease characterized by flaccid paralysis.
select the FALSE statement regarding bacterial diversity.
During unfavorable conditions, myxobacteria travel as a pack to a new location.
what would happen if we remove the electron transport chain of e coli
prevent oxidative phosphorylation.
define primary producers
consumers
decomposers
decomposers Heterotrophs that digest the remains of the other two groups in ecosystems; specialize in digesting complex molecules such as cellulose.
consumers Heterotrophs that eat other organisms; several together can create a food chain, while multiple chains create a food web.
primary producers Autotrophs that convert CO2 into organic materials; serve as a food source for other ecosystem members.
define phosphorylation
Synthesis of ATP using the energy of a proton motive force created by harvesting radiant energy.
Bacteria in aquatic environments have evolved various mechanisms to maximize nutrient uptake and retention. Why?
Multiple Choice
Most aquatic environments lack a steady supply of nutrients.
what are the elements that undergo biogeochemical cycling
carbon and nitrogen
sulfur and phosphorous
A worker in a cheese-making facility argued that whey, a nutrient-rich by-product of the process, should be dumped into a nearby pond to serve as fish food. Is this a good idea or a bad one, and why?
Bad idea—bacteria would thrive on this rich nutrient source and multiply, using the oxygen in the water to harvest the energy from the whey. Without the oxygen, the fish will die.
Correct
describe methanogens
Archaea, live in anaerobic environments with H2 and CO2.
Found in mud with organic material and oxidized sulfur compounds sulfate reducig bacteria
lactic acid bacteria Gram-positive, catalase-negative, grow in aerobic environments but only ferment, producing acidic conditions.
pronibacterium species vs clostridum species
Gram-positive pleomorphic (irregular shaped) rods, fermenters, often used in Swiss cheese production is pronibacterium
clostridum species Generally in endospore form in soil, but will germinate to vegetative form when anaerobic conditions arise. Gram-positive rods.
bacteria that can absorb light energy and convert it into ATP are commonly called
photrophs
Fermentation is sometimes used as a means of slowing food spoilage. Why would fermentation lead to this outcome?
Fermentation will lead to production of acidic by-products, dropping the pH of the food below a level that bacteria can tolerate.
Methanogens are a group of archaea that generate ATP by
oxidizing hydrogen gas using carbon dioxide as a terminal electron acceptor
The most common starting pathway for the breakdown of sugars is
glycolysis
A culture of bacteria is breaking down sugars to yield energy. This is best described as ______.
catabolism
How do chemolithotrophs acquire energy?
From inorganic compounds
what does the transition step do
links glycolysis to the TCA cycle
Organisms growing in pulmonary mist therapy unit fluid reservoirs can be problematic because they
may cause disease in hospitalized patients treated with the contaminated fluids.
what does the electron transport chain require
requires a membrane AND generates a concentration gradient of protons.
Place the steps involved in creating an aquatic dead zone into the correct sequence.
River water carrying nutrients acquired from urban, agricultural and industrial areas flows into the sea.
Algae and cyanobacteria (primary producers) use excess phosphates and nitrates for growth, multiplying rapidly.
Heterotrophic microbes metabolize the organic compounds made by primary producers, and consume dissolved O2.
Depletion of dissolved O2 results in large hypoxic zone, causing animals to flee or die.
Which of the following bacteria can oxidize metal compounds exposed during strip mining of coal, dramatically lowering pH and leading to damaging acid run-off into the surrounding ecosystem?
Sulfur-oxidizing bacteria
Which of the following are TRUE regarding purple sulfur bacteria, purple non-sulfur bacteria, and green sulfur bacteria?
They are anoxygenic phototrophs. Correct
They all use sunlight as an energy source.
Select the TRUE statement regarding Agrobacterium species
they stimulate tumor-like growths in plants to obtain nutrients.
Cyanobacteria have evolved elaborate mechanisms for preventing O2 from coming into contact with the nitrogenase enzyme. Why?
Nitrogenase enzyme complexes are damaged or destroyed by O2.
what is the proton motive force
is used to synthesize ATP.
Match the description for each method of nutrient acquisition/retention that may be used by aquatic bacteria.
Form
ation of storage granules (example Thiomargarita)
Accumulation of sulfur, nitrate, phosphate, etc. within the cell’s cytoplasm.
describe Unusual movement mechanisms (example Magnetospirrilum)
Using a special type of flagellum housed within the periplasm to move through thick mud/sediment towards nutrients, or using a string of magnetic crystals in the cell to orient within the Earth’s magnetic field to migrate towards nutrient-rich areas.
describe Prosthecate bacteria (example Caulobacter)
Extensions of the cytoplasm and cell wall are used to increase surface area for absorption of nutrients (and possibly for attachment to solid surfaces).
describe sheathed bacteria example sphaerotilus
Cells form chains encased within a tube. This plays a protective role, allowing the cells to attach to solid objects in nutritionally favorable habitats.
describe predator of other organisms
Bacteria may prey upon other bacterial cells directly, form symbiotic relationships with larger eukaryotic organisms in exchange for nutrients, or reside within fish/protozoa without either harming or helping the host organisms.
Consider how an aerobically respiring bacterial cell uses glycolysis, the TCA cycle, and oxidative phosphorylation to break apart and oxidize glucose. What are the three main benefits these central metabolic pathways yield to the cell?
ATP, reduced electron carriers, and precursor metabolites
What shape is the cyanobacterium used in this work?
The name of the organism is Synecococcus elongatus. Remember that “coccus” means round or spherical. R
why did the rats that had light shone on the bacteria in their hearts do better than the rats that did not have light shone on the bacteria in their hearts?
cyanobacteria are photosynthetic. Photosynthesis is the process by which an organism uses water and energy from light to convert carbon dioxide into glucose, releasing oxygen as a byproduct. The bacteria in the illuminated hearts produced more oxygen than those in the non-illuminated hear
Which of the following are mutualistic relationships?
Rhizobia in legume root nodules.
Microbes in digestive organs of herbivores.
Mycorrhizas in/on plant roots.
which of the following factors can influence the ability of an organism to compete successfully for a habitat?
The rate at which the organism multiplies.
The ability of the organism to inhibit other microbes by producing antimicrobial compounds.
The ability of the organism to withstand adverse environmental conditions.
Match each of the following obligate aerobic bacteria with its description.
Deinococcus species
deinococcus species Stain Gram-positive, with an odd multilayer cell wall that lets the cells resist high levels of gamma radiation (also due to their extensive DNA repair enzyme activities).
micrococcus species
Gram-positive cocci found in soil, dust particles, inanimate objects, skin; tolerates dry and moderately salty conditions.
pseudomonas species
Gram-negative rods with polar flagella. Often produce pigments. Widespread in soil and water. Most are harmless, but some can be opportunistic pathogens of humans.
thermus species
Stain Gram-negative, but have an unusual cell wall. Survive well in high heat, due to their interesting heat-resistant enzymes.
mycobacterium species
Generally pleomorphic (variable shape) rods that stain poorly and resist destaining due to waxy lipids in their cell wall structure. Several species cause human diseases.
Which of the following would be most important in establishing herd immunity?
Inoculating the majority of people in a population with measles vaccine.
Please select the INCORRECT statement regarding cell communication.
Adhesion molecules are molecules on the inside of a cell that allow that cell to grab and destroy damaging component
The peptides presented by MHC class II peptide molecules are
exogenous antigens.
Please place the following events in the correct order to test your understanding of the mechanism of action of desensitization or “allergy shots.”
Diluted but gradually increasing concentrations of pure allergen are injected.
Allergen-specific IgG antibodies are produced by B cells.
IgG binds to allergen before it can bind IgE.
Degranulation of mast cells is prevented.
Apoptosis is
a type of cell death that does not initate inflammation
A patient is suffering from a severe case of influenza, caused by influenza virus. He takes analgesics (painkillers) and also a fever-reducing medication, and after a few days begins to feel better. However, just as he thinks he will be able to return to school, the patient suddenly worsens, developing chest pain, and a productive cough (coughing up sputum). When he notices that his sputum contains blood, he goes to the doctor who diagnoses pneumonia, caused by the bacterium Streptococcus pneumoniae. In this scenario, the influenza virus is ______ while the S. pneumoniae is _______.
Multiple Choice
a primary pathogen; an opportunistic pathogen
place the statements about the progression of a disease into the correct order, from start to finish.
Incubation period—time between entry of a microbe into a host and the start of signs and symptoms.
Prodromal period—period of early, vague symptoms such as malaise.
Illness phase—infected person experiences signs and symptoms of the disease.
Convalescence phase—period during which signs and symptoms disappear and the person recovers.
Select all of the statements that apply to a primary response to a T-dependent antigen:
Produces mainly IgM antibodies, but undergoes class switching to other classes near the end of the response.
fiine-tunes and increases strength of binding of antibody to antigen through the process of affinity maturation.
Takes 10–14 days to build a substantial amount of antibodies in the bloodstream.
Antibodies are made by
B cells/plasma cells.
You inform your patient that the human body has several mechanisms of defense: innate immunity, which is routine protection present at birth, and adaptive immunity, which is a more specific response that develops after birth. You tell your patient that her adaptive immune response uses two basic strategies for eliminating foreign material: humoral immunity, which involves ______ and cell-mediated immunity, which involves ______.
B lymphocytes; T lymphocytes
You explain to your patient the role of the lymphocytes in her adaptive immune response. In the middle of your explanation, you are distracted and you tell her something that is NOT correct. Identify that statement.
After activation, T lymphocytes divide and proliferate to form a population of helper T cells and a population of cytotoxic T cells; activated T cells secrete cytokines that exert an effect on other cells.
You describe for your patient the sequence of events that occurs when a B cell is activated. Please select the correct order of statements.
- TH cells recognize the presented antigen-MHC complex on the B cell and bind to it.
- B cell receptor binds to an antigen and the antigen is internalized by endocytosis.
- The bound TH delivers cytokines to the B cell that initiate the process of clonal expansion of that particular B cell.
- The antigen is degraded and peptide fragments are expressed at the B cell membrane with MHC class II molecules
. B cell receptor binds to an antigen and the antigen is internalized by endocytosis.
The antigen is degraded and peptide fragments are expressed at the B cell membrane with MHC class II molecules.
TH cells recognize the presented antigen-MHC complex on the B cell and bind to it.
The bound TH delivers cytokines to the B cell that initiate the process of clonal expansion of that particular B cell.
Your patient has recently been diagnosed with an immunodeficiency disorder. Your supervisor asks you to help the patient understand what this means and the impact it will have on her.
You explain to your patient the role of cytotoxic T cells in immunity, telling her that
TC destroy cancerous “self” cells AND TC cells induce apoptosis in infected “self” cells.
The chickenpox vaccine is not recommended for someone who has AIDS or a similar immunodeficiency. Based on this information, you conclude that the vaccine likely
contains an attenuated strain.
he TRUE statements about primary immunodeficiencies.
these diseases are rare and may be life threatening
these disorders reslult from a genetuc disorder
examples of the disorders are scid and cgd
describe neutrophild and basophils
neutrophils is the main phagocyte in circulation
basophils like eosinphils are invovlved in inflammation and allergic reactions
describe monocytes and natural killer cells
natural killer cells Display no antigen specificity but are active against tumor and virally infected cells
monocytes Phagocytic cells that leave circulation and differentiate into macrophages
define interferons
These proteins are often secreted when viral RNA is detected which signals neighboring cells to express antiviral proteins.
define rlrs
These proteins are found in the cytoplasm and can detect viral RNA
define tlrs
These receptors are found anchored in sentinel cells like macrophages and dendritic cells.They can bind to foreign structures like dsRNA, ssRNA and some bacterial DNA fragments.
define nlrs
These proteins are found in the cytoplasm and can detect bacterial components.
drscribe igg ige igd igm iga
igD Involved in maturation of B lymphocytes and antibody responses, but function is largely uncharacterized.
ige Binds via Fc region to mast cells/basophils. Involved in allergic responses and responses to parasites
igm First class produced in primary response. Forms a pentamer. Helps activate complement through the classical pathway.
igA Most abundant class overall, but mainly found in mucosal secretions. Generally found as a dimer.
igg Main class found in blood. Only class that can cross the placenta. Found as a monomer.
What two functions do phagocytes serve in immune responses?
Multiple Choice
Engulfment/destruction of foreign cells AND alerting the other cells of the immune system to an invader.
Despite the evidence indicating how important vaccines are, some people have chosen not to vaccinate their children. Select the TRUE statement
Diseases like measles and pertussis, once mostly prevented by vaccination, are reappearing in the United States because people fail to immunize their children.
Vaccines have been so successful that some people have forgotten how serious some childhood diseases can be.
opsonization
Coating of microbe with antibody to enhance phagocytosis
neutrilization
Antibodies fill the surface receptors on microbe to prevent attachment to the host
complement system activation
mmune complexes activate complement proteins, leading to inflammation and production of MACs
Immobilization and prevention of adherence
Antibodies bind to flagella preventing movement or to pili preventing attachment of bacteria
Cross-linking
Formation of large Ab-Ag complexes as a result of the Ab binding two separate antigens
Antibody-dependent cellular cytotoxicity (ADCC)
IgG molecules attach to a cell targeting it for attack by a NK cell
How is a T-cell receptor different from a B-cell receptor?
-cell receptors must have antigen broken down inside a cell and presented to them by a major histocompatibility complex (MHC) molecule.
hy would a person who has their tonsils removed be more susceptible to certain types of infections of the throat and respiratory tract?
Tonsils are secondary lymphoid organs; they help to provide a constant response to the microbes in the oral cavity, helping to keep them in check and preventing them from spreading to other areas.
A group of interacting serum proteins that provide a nonspecific defense mechanism i
complement sytem
When microbes are introduced into normally sterile body sites, or when tissues are damaged, inflammation occurs. The purpose of this is to contain a site of damage, localize the response, eliminate the invader, and restore tissue function. Select the correct sequence of events for an inflammation response.
1. The phagocytes then produce other adhesion molecules that strengthen their attachment to the endothelial cells.
- Tight junctions between endothelial cells are disrupted, allowing leakage from the vessels into the tissue.
- Endothelial cells of the blood vessels produce adhesion molecules that loosely “grab” phagocytic cells.
- In response to various chemoattractants, the phagocytes leave the blood vessels and move into the surrounding tissues.
- The diameter of local blood vessels increases due to the action of inflammatory mediators, slowing blood flow in the area.
52314
elect the statements about self-tolerance that are TRUE.
Check All That Apply
Self-tolerance occurs because lymphocytes that recognize autoantigens undergo apoptosis in the thymus (negative selection).
Lymphocytes that recognize autoantigens are filtered out by the spleen.
which of the following are mechanisms by which neutrophils are able to destroy microbial invaders?
They can engulf invaders, destroying them with their granules in a regular phagocytic process.
They can explode in tissues, releasing their granules and DNA to create NETs for trapping and destroying invaders.
They can degranulate, releasing their destructive enzymes that then destroy invaders in tissues.
what is commenalis,
In this relationship, one organism benefits and the other remains unharmed.
what is paratism
In this relationship, one organism benefits while the other is harmed.
mutualism
In this relationship, both organisms benefit
type 1
ncludes anaphylaxis—a systemic fatal reaction with airway obstruction and respiratory collapse
type 2
Involves complement-assisted lysis of cells coated with antibodies as seen in transfusion reactions
type 3
immune complexes form and become lodged in blood vessel wall
type 4
T cell–mediated delayed hypersensitivity reactions including contact dermatitis and graft rejection reactions
How long after initiation of a primary response do significant amounts of antibody appear in the blood?
10=14 days
Which of the following are limitations of Koch’s postulates?
The suspected pathogen cannot be cultured in the laboratory
There is not a suitable experimental host for the suspected pathogen.
The disease is polymicrobial, caused by more than one pathogen.
A monoclonal antibody suspension
is produced by immortalized B cells.
Why are people with B-cell deficiencies more susceptible bacterial infections, whereas people with T-cell deficiencies are more susceptible to viral infections?
Bacteria usually remain outside a cell where they can be bound by antibodies, made by B cells. Viruses enter cells so they must be destroyed by eliminating those cells, an action of T cells
CD4 cells are also known as
T helper cells.
cytokines
Chemicals that direct certain cell activities.
adjuvants
Agents that boost the immune system.
Checkpoint inhibitors
Monoclonal antibodies that block peripheral tolerance pathways.
car t cel;s
T cells genetically engineered to recognize a specific epitope.
oncolytic vituses
Genetically modified viruses that attack cancer cells.
immunotherapies
Therapies that either boost or suppress the immune system.`
