CPA #2 Questions Flashcards
why is it important to classify organisms?
bring sense of order/ organization; to enhance communication; to make predictions about the structure and function of similar organisms; to understand evolutionary connections
what are the 5 kingdoms?
- Animalia
- plantae
- fungi
- protista
- prokaryotae
what are the 3 domains?
- eukarya
- bacteria
- archaea
what is the difference between prokaryotes and eukaryotes?
domain eukarya contain nucleus;
domains bacteria and archaea do NOT contain nucleus
what are the 5 types of information used to differentiate microbes?
- physical characteristics
- biochemical tests
- serological tests
- phage typing
- analysis of nucleic acids
differentiate microbes using the sequence of nucleotides in nucleic acid molecules
analysis of nucleic acids
differentiate microbes using phages, which are unique and specific to the host
phage typing
differentiate using antigen-antibody testing
serological tests
differentiate microbes using the differences in microbe ability to utilize or produce certain chemicals
biochemical tests
differentiate microbes based solely on their morphology
physical characteristics
what is microbial antagonism?
normal microbiota use nutrients, take up space, release toxic waste products, which make it less likely for arriving pathogens to become established + produce diseases.
is microbial antagonism good or bad? why?
good; under normal circumstances it is good because it reduces likelihood of pathogens to produce diseases
what are the 3 key elements of microbial antagonism?
- take up space
- take up nutrients
- change pH in area
define zoonoses
diseases that spread naturally from animal to human
why are humans dead-end hosts for zoonotic pathogens?
humans are not significant reservoirs for the reinfection of animal hosts; animals do not often eat humans and animals have less common contact with human waste
can an asymptomatic human carrier be infectious?
yes; some carriers incubate pathogen and eventually develop the disease, others remain a continued source of infection without ever getting sick.
how do adhesion factors determine host specificity?
specific interactions of adhesions and receptors with chemicals on host cells
define biofilm
pathogens that attach to each other to form a sticky web of bacteria and polysaccharides which adheres to a surface
what is an example of a biofilm?
dental plaque
define contamination
contact with the pathogen
define infection from contamination
pathogen is able to gain access to body (skin break, etc)
define disease from contamination
multiplication of pathogen resulting in adverse conditions
define symptom
subjective characteristics; felt by patient
define sign
objective characteristics; observed or measured by others
define syndrome
group of symptoms and signs that collectively characterize a particular disease
define sequela
a condition which is the result of previous injury or disease
why are subclinical infections so hard to treat?
they lack symptoms so they go unnoticed; patient feels fine, but there may be signs; asymptomatic
what is the purpose of Koch’s Postulates?
to prove that a given infectious agent causes a given disease
what are Koch’s 4 Postulates
- the suspected agent present in every case of the disease.
- that agent must be isolated and grown in pure culture
- the cultured agent must cause the disease when inoculated into healthy susceptible experimental host
- the same specimen should be found in the diseased experimental host
why can’t Koch’s postulates always be used
some pathogens have never been cultured; some diseases are caused by combination of pathogens; ethical reasons
what areas of digestive system are normal microbes found?
tongue, teeth, jejunum, ileum, colon, rectum
what areas of digestive system are axenic (no microbes)?
esophagus, stomach, duodenum
how do intestinal microbes protect the body?
outcompeting pathogens (microbial antagonism); produce vitamin B12, folic acid, biotin, vitamin K, daily flatus
how can oral antimicrobials affect these normal microbes?
inhibit intestinal microbiota, undermining defensive properties; long term loss can allow colonization of pathogenic microbes.
