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BIOL 200 Exam 4 questions and answers 100% verified
Some animal viruses, such as human herpesvirus 1, infect a cell without causing symptoms.
These are best termed:: latent viruses
Which of these are ways an animal virus can infect a cell?
all of these membrane fusion endocytosis direct penetration: all of these
What is the type of relationship in which both organisms benefit from one another?: mutualism
Which of these diseases is caused by the reactivation of a latent virus?: -
shingles
All of the following encourage the development of opportunistic pathogens EXCEPT:
exposure to a nonliving reservoir. invasion of an unusual body site by the normal microbiota. immune suppression in the host. changes in the host's normal microbiota.`: exposure to a nonliving reservoir
All of the following are examples of noncommunicable diseases EXCEPT: influenza
acne tooth decay tetanus: influenza
are soluble substances secreted from bacteria into host tissues, whereas
are part of the bacterialcell wall and are released during cell division, as a result of cell damage, and/or after cell death. proteins / lipopolysaccharides
lipopolysaccharides / proteins endotoxins / exotoxins exotoxins / endotoxins: exotoxins / endotoxins Which of the following definitions is INCORRECT? pandemic: a disease that affects a large number of people in the world in a short time incidence: number of new cases of a disease endemic: a disease that is constantly present in a population epidemic: a disease that is zoonotic across the world: epidemic: a disease that is zoonotic across the world
Robert Koch's work primarily involved the:
epidemiology of infectious diseases ecology of infectious diseases emergence of infectious diseases etiology of infectious diseases: etiology of infectious diseases
Which of the following is the correct definition for a latent disease a disease without
symptoms disease in which symptoms develop rapidly and it runs its course quickly a disease that appears after a long time of infection a disease with mild symptoms that develop slowly and last a long time: a disease that appears after a long time of infection
When only a few scattered cases occur within an area or population, the disease is said to be
. Sporadic to that population/area Endemic to that population/area Pandemic to that population/area Symptomatic to that population/area: sporadic to that population/area
prevent microorganisms from acquiring drug resistance reduce the side- effects of antibiotics: all of the above
Antimicrobial drugs with a high "therapeutic index" are generally
compared to drugs with a low therapeuticindex. safer more allergenic more potent more dangerous: safer
What does MIC [also known as the MIC50] stand for, in the context of drug therapy?
Minimum inhibitory concentration Microphone input jack Microbial inactivation concentration Maximum insensitive concentration: minimum inhibitory concentration
Some areas of the second line of defense would not include? fever
phagocytosis inflammation Mucous Membranes: mucous membranes
lytic cycle: a viral reproductive cycle in which copies of a virus are made within a host cell,
which then bursts open, releasing new viruses
bacteriophage lambda: performs lysogenic replication/lysogeny
bacteriophage lamba infects: bacteria (prokaryotes)
bacteriophage lambda: This virus infects the Gram-negative bacterium Es- cherichia coli, it
has both lytic and lysogenic stages (in regards to bacteriophages, the term "lysogenic stage" means essentially the same thing as a "latent stage" in human/animal viruses), Bacteriophage lambda is a double stranded DNA virus with a complex capsule and no envelope
prophage: the viral DNA that is embedded in the host cell's DNA
induction: virus leaves lysogenic phase and acts like a "sleeper cell"
3 mechanisms of animal viruses: direct penetration membrane
fusion endocytosis
direct penetration: Enveloped viruses fuse directly with the plasma membrane of the host
cell
membrane fusion: Enveloped virus melts into the cytoplasmic membrane of the host cell
Endocytosis viral entry: virus triggers the cell to engulf it/"take a bite out of it" then virus
replicates parts once inside
endocytosis, membrane fusion: distinct to animal viruses!!
because there is no cell wall on animals
Which of the following definitions is INCORRECT?
prophylaxis: use of a drug to treat a person with a chronic infection antibiotic: a microbial- produced chemical that inhibits the growth of or kills other microorganisms chemotherapy: use of any chemical agent to treat disease antimicrobial agent: chemical agent used to treat a disease caused by mi- crobes: prophylaxis: use of a drug to treat a person with a chronic infection
Which of the following is most closely associated with beta-lactam ring? Bacitracin
Isoniazid Penicillin Vancomycin: penicillin
The antibody that is secreted as a pentamer, and the first antibody secreted during early stages
of a primary response IgA IgG IgE IgM: IgM
What type of immunity can result from getting an infection? Naturally
acquired active immunity Passively aquired artificial immunity artificially acquired passive immunity Naturally aquired passive immunity: naturally acquired active immunity
Antibodies function to.
directly destroy foreign organ grafts mark invading organisms for destruction kill intracellular viruses stimulate T cell growth: mark invading organisms for destruction
MHC class I molecules are found on ; MHC class II molecules are
found on .: all human cells, antigens
T cells..
secrete antibodies mature in the bone marrow are part of the cell-mediated immune system often ingest pathogenic microbes: are part of the cell-mediated immune system
neoplasia: new growth
phage typing: -Identification of bacterial species and strains by determining their
susceptibility to various phages. -can grow viruses in the lab by growing their respective host cells, need host cell to grow more of virus
viroid: extremely small, circular piece of RNA that is infectious and pathogenic in plants
dramatic outcomes, made of pure nucleic acids
prions: infectious proteins
replication of animal viruses involves: 1. attachment
2.entry
3.uncoding
4.synthesis
5.assembly
6.release
methods of entry: direct penetration
membrane fusion endocytosis
viral release methods: budding, lysts, shedding
viral entry methods specific to animal viruses: membrane fusion and endo- cytosis
mutualism: A relationship between two species in which both species benefit
commensalism: A relationship between two organisms in which one organism benefits and
the other is unaffected ex: mites in human hair follicles
amensalism: a relationship in which one organism is harmed and the other is unaffected
ex: fungus secreting an antibiotic, inhibiting nearby bacteria
parasitism: A relationship between two organisms of different species where one benefits
and the other is harmed ex: pathogen
resident microbiota: Are a part of the normal microbiota throughout life Are mostly
commensal feed on cellular wastes, cause no harm
transient microbiota: the microorganisms that are present in an animal for a short time
without causing a disease
ex: stay for days, weeks, months usually found on top of hands, mouth, etc
normal microbiota: permanently colonize the host and do not cause disease under normal
conditions developed from the mother's womb
resident microbiota are: permanent
transint microbiota are: temporary
Changes in normal microbiota: microbial antagonism microbial
competition
microbial antagonism: competition between microbes
microbial competition: Normal condition in which established microbiota use up available
nutrients and space, reducing the ability of arriving pathogens to colonize.
opportunistic pathogen: causes disease only in the absence of normal host resistance
Epidemiology: Branch of medical science concerned with the incidence, distri- bution, and
control of diseases that affect large numbers of people.
reservoir: where pathogens live and multiply
zoonoses: Diseases transmitted from animals to humans
carriers: people who carry pathogens and infect others without getting sick themselves
do both healthy and unhealthy people transmit diseases?: yes
non-living reservoirs: soil, water, food
exposure: when you are first exposed/come in contact with the pathogen
infection: pathogen has now entered the body, multiplied
How do pathogens enter the body?: through any hole
broken skin, insect bite, ear, anus, mouth, nose, eye, genitals, placenta
mucous membranes: thin sheets of tissue that line respiratory passages and secrete
mucus, a viscid (sticky) fluid
parenteral route: a portal of entry for pathogens by deposition directly into tissues
beneath the skin and mucous membranes
parenteral routes include: cuts, bites, stabs, nail, thorn, needles
goes directly into tissues, under the mucous membranes
virus life cycle stages: 1. attachment
2.entry
3.synthesis
4.assembly
5.release
4.ethical issues
5.some diseases caused by combination of pathogens and there are other factors
hereditary disease: a disease caused by defective genes inherited by child from one or
both parents
congenital disease: born with it
degenerative disease: a disease that causes a breakdown of the body cells, tissues, and
organs as it progresses getting old with time
nutritional disease: Disease caused by lack of nutritious food, too little food, or an
inability to utilize the food that is eaten
endocrine disease: due to excesses or deficiencies of hormones
mental disease: disease of the mind, not the equivalent of insanity
immunological disease: hyperactive or hypoactive immunity
neoplastic disease: Condition related to a tumor or growth
infectious disease: a disease caused by a pathogen
iatrogenic disease: a condition that is caused by a medical treatment
idiopathic disease: disorder of unknown cause
Health care-associated infections (HAIs) or nosocomial: An infection that is acquired in a
hospital setting, formerly known as a nosocomial infection
Dr. Berry Marshall: -proved that stomach ulcers were caused by bacteria not high acid
content, which was what most believed -used Koch's postulates -he drank the culture and infected himself -took antibiotics and got better -won nobel prize -heliobacter pylon causes ulcer, so use antibiotics
more virulent: harmful, easily transmitted
more virulent pathogens: francisella tularneis (rabbit fever) plague,
whooping cough
less virulent pathogens: lactobacilli, diphtheroids
how do pathogens become more virulent?: more virulent factors "weapons"
toxins: poisonous or harmful substances
virulence factors: traits used to invade and establish themselves in the host, also
determine the degree of tissue damage that occurs - severity of disease increase the ability to cause disease
virulence factors include: toxins, enzymes, capsules
noncommunicable disease: a disease that is not transmitted from one host to another
extracellular enzymes (virulence factors): made outside of the cell ex: kinases
digest clots enzymes that break down proteins and then "open door" for bacteria to enter include hyaluronidase and collagenase
toxins: Chemicals that harm tissues or trigger host immune responses that cause
damage
two types of toxins: exotoxins and endotoxins
exotoxins: soluble substances secreted into host tissues secreted
outside of the cell, affect occurs outside of the cell
types of exotoxins: cytotoxins, neurotoxins, enterotoxins
generally proteins
cytotoxins: kill cells
neurotoxins: Chemicals that affect the nervous system
enterotoxins: act on the gastrointestinal tract
endotoxins: released only when bacteria die and their cell walls break down
endotoxins can be released when: gram negative bacteria divide or die naturally
releases lipid A
release of lipid A: causes severe affects, the release of endotoxins from dead bacteria can
be deadly
Antiphagocytic factors: virulence factors that help pathogens to avoid phago- cytes
Antiphagocytic factors include: capsules and antiphagocytic chemicals
exotoxins (details): source: gram negative and gram positive bacteria metabolic
product secreted from living cell chemical nature: protein or short peptide high toxicity variable effects on hosts, depends on source no fever strong antigenicity can form toxoids
endotoxins (details): source: gram negative bacteria portion of
outer membrane (cell wall) released upon cell death chemical nature: lipid portion of outer cell wall (lipid A) low toxicity, but fatal in high doses
portal of exits are: specific to specific microbe
-portal of exit and portal of entry may be the same ex: respiratory tract infection portal of exit=sneezed out of lungs portal of entry=inhaled into another's lungs
modes of transmission: contact, vehicle, vector
contact transmission: direct, indirect, droplet
direct contact transmission: person to person transmission
indirect contact transmission: spreads to a host by a nonliving object called a fomite
fomite: A physical object that serves to transmit an infectious agent from person to
person.
droplet transmission: transmission via airborne droplets less than 1 meter
person to air to person: droplet transmission
person to person: direct contact transmission
person to thing to person: indirect contact transmission
vehicle transmission: spread of pathogens via air, drinking water, and food, as well as
bodily fluids being handled outside the body
vehicle transmission includes: airborne, waterborne, food borne
airborne transmission: occurs through contact with contaminated respiratory droplets
spread by a cough or sneeze, farther than 1 meter, via aerosols
waterborne transmission: pathogens are usually spread by water contami- nated with
untreated or poorly treated sewage fecal oral infection
food borne transmission: spread of pathogens in or on food
vector transmission: transmission of an infectious agent by an insect, arthro- pod, or
animal biological or mechanical
mechanical vector: not necessary to the life cycle of an infectious agent and merely
transports it without being infected
biological vector: actively participates in a pathogen's life cycle
acute disease: symptoms develop rapidly, short time
chronic disease: an ongoing condition or illness
subacute disease: symptoms between acute and chronic
asymptomatic disease: disease without symptoms
latent disease: disease that appears a long time after infection
communicable disease: a disease that is spread from one host to another
local infection: pathogens are limited to a small area of the body
contagious disease: a disease that is easily spread from one host to another
systemic infection: an infection throughout the body
focal infection: one in which the organisms are originally confined to one area but enter
the blood or lymph vessel and spread to other parts of the body
primary infection: initial infection
secondary infection: opportunistic infection after a primary (predisposing) infection
incidence: number of new cases
prevalence: total number of cases (new and old)
antiviral drugs caused: prevalence to increase bc people livid longer
sporadic disease: disease that occurs occasionally in a population
endemic disease: disease constantly present in a population
epidemic disease: over normal expected level in certain area
pandemic disease: worldwide epidemic
Nosocomial & healthcare-associated infections (HAIs): -preventable
-really serious and common -problematic because people who are carriers and people who are susceptible are in the same place
exogenous HAI: pathogen acquired from the health care environment
endogenous HAI: pathogen arises from normal microbiota within the patient become
pathogenic due to factors within the health care setting
iatrogenic infections: infections that are the direct result of diagnostic or therapeutic
procedures "doctor induced"
superinfections: result from use of antimicrobial drugs that inhibit some nor- mal
microbiota allow other organisms to thrive in absence of competition
control of HAIs: Reduce number of pathogens
Handwashing Disinfecting tubs used to bathe patients Cleaning instruments scrupulously Using disposable bandages and intubation Infection control committees team effort
mortality: death rate
morbidity: how many people are sick
john snow: father of epidemiology
stopped cholera epidemic before the germ theory of disease
drug targets: have important biochemical or physiological roles, and drugs interact with
them, either blocking, inhibiting, or activating them, with biochemical
-inhbity nucleic acid synthesis -block recognition or attachment
inhibit protein synthesis: -target the 70s ribosomes of prokaryotes (to harm bacteria)
-do not target the 80s ribosomes of eukaryotes (the host)
penicillins: drugs similar to penicillin, share beta lactam ring and similar func- tion
Disruption of Cytoplasmic Membranes: -best for fungi, anti fungal drugs
-fungi have ergosterol in membrane and humans don't
analog: chemical look alike
sulfanilamide: -analog of PABA
-has a different functional group attached to the B lactam ring -normally PABA is the substrate for biochemical pathway of folic acid synthesis -but the enzyme can also fit sulfanilamide into active site (instead of PABA) -dihydrofolic acid is not produced, can't make folic acid, can't make nucleotides, cell dies
Inhibition of nucleic acid synthesis: interfere with the synthesis of DNA and/or RNA
typically done with nucleoside or nucleotide analogs does not have good selective toxicity, because only slight differences present be- tween DNA of prokaryotes and eukaryotes -avoid using
spectrum of action: the number of different kinds of pathogens a drug acts against
broad spectrum: ability of a drug to be effective against a wide range of
microorganisms ex: sulfanalimide
narrow spectrum: effective against few or a single species
usually preferred because less side effects, safer
Ideal Antimicrobial Agent: Readily available
Inexpensive Chemically stable Easily administered Nontoxic and nonallergenic Selectively toxic against wide range of pathogens
disk diffusion test: `-disks impregnated with specific drugs are placed on agar plates
inoculated with test microbe
-drug diffuses from disk into agar, establishing concentration gradient -observe clear zones (no growth) around disks
zone of inhibition: Region around a chemical saturated disc, where bacteria are unable to
grow due to adverse effects of the compound in the disc.
Minimum inhibitory concentration (MIC): the minimum concentration of a substance
necessary to prevent microbial growth concentration at the edge of zone of inhibition
dosing regiment is important: to maintain the drug concentration in the effective
range
therapeutic index/window: -difference between the drugs effective level and lethal level
concentration at which drug kills all of the bacteria and harms none of the host
High therapeutic index: less toxic to the patient. safer,
less side effects
Low therapeutic index: narrow margin of safety harsh
side effects, such as cancer drugs
over the therapeutic index: toxicity, allergies, disruption of normal microbiota
Below therapeutic index: resistance to antimicrobials
Mechanisms of Drug Resistance: -inactivation of the drug
-alteration or loss of drug target -decreased entry of drug into cell -rapid efflux of the drug -produced enzyme that deactivates or destroys
Prevent drug resistance: -use right medication for right purpose
-screening tests to look for synergism -combination drug therapy
drug synergism: occurs when drugs interact to produce effects greater than those that
each drug would produce alone
prophalaxysis: giving antibiotics to prevent disease
immune system consists of: primary line, secondary line and third line of defense
First line of defense: skin and mucous membranes and their features purpose is to
try to keep things out
Hematopoiesis: formation of blood cells, forms different types starts
from stem cell in bone marrow
plasma: Liquid part of blood, made mostly of water, in which oxygen, nutrients, and
minerals are dissolved
granulocytes: have granules in cytoplasm, can have degranulation
granules: a small compact particle of a substance.
lymphatic capillaries: Small, open-ended lymph vessels that act like drain pipes which
picks up lymph at tissues throughout the body
lymph nodes: Bean-shaped filters that cluster along the lymphatic vessels of the body.
They function as a cleanser of lymph as wells as a site of T and B cell activation recognizes shapes
epitope: Small, accessible portion of an antigen that can be recognized. shape
antigens: molecules that provoke a specific immune response
An antibody generator: antigen
an antigen has: multiple epitopes(shapes) on it
antibodies found in blood: know that antigen is present and there was an immune
response
exogenous antigens: include toxins and other secretions and components of microbial cell
walls, membranes, flagella, and pili outside the body
endogenous antigens: foreign antigens that are present inside body cells
autoantigens: derived from normal cellular processes
Major histocompatibility complex (MHC) proteins: cell surface proteins with a groove for
holding self-antigen or foreign antigen
2 classes of MHC proteins: Class I and Class II
Class I MHC: -found on all nucleated cells
-"ID badge" -make sure its your cell -displays shapes from inside the cell, what it has been working on
Class II MHC: found only on antigen-presenting cells "hunting
license" displays what cell has recently eaten or killed
dendritic cells: antigen-presenting cells in the skin have
class 1 and 2 MHC receptors
2 parts of adaptive immunity: cell mediated and humoral mediated
cell mediated: T cells stick to target cell and kill it
HAPPENS IN CONTACT
humoral mediated: antibody mediated, B cells
distinctive attributes of adaptive immune system: specificity inducibility
clonality unresponsiveness to self memory
specificity of adaptive immunity: ability to recognize a particular substance, will react
strongly to substances it has seen before
inducibility of adaptive immunity: activated by pathogen
clonality of adaptive immunity: once induced, cell proliferates to form many
generations/clones
unresponsiveness to self: does not act against normal body cells
memory of adaptive immunity: you remember it keeps
you from getting sick again
to get a fully activated immune response: T cells and B cells need to communicate
with each other interaction causes memory response need both humoral and cell systems to be activated
T cell receptor (TCR): Molecule on the surface of a T cell that can bind to a specific
antigen fragment in combination with an MHC molecule.
clonal deletion: screening T cells, deleting T cells that recognize autoantigens
apoptosis: process of programmed cell death deleting
T cells that recognize autoantigens
T lymphocytes: form in the thymus and other lymphatic tissue and attack cancer cells,
viruses, and foreign substances
B cell receptor (BCR): Molecule on the surface of a B cell that binds to a specific
antigen.
B cell receptor structure: -transmembrane polypeptide
-heavy chain and light chains that are identical forms Y shape 4 pieces held by covalent (disulfide) bond epitope/antigen binding sites are at the hands of receptor recognize identical shapes arm hinge and stem regions
Clonal deletion of B cells: -Occurs in the bone marrow in a manner similar to deletion of T
cells -Self reactive B cells may become inactive or change their BCR rather than undergo apoptosis
neutralization: toxin molecule is covered up by antibodies, a coating
opsonization: coating antigen with antibody enhances phagocytosis
oxidation: antibodies stimulate oxidative stress and kill bacteria
agglutination: clumping of red blood cells 1
antibody binds to multiple molecules holding hands
