Midterm COPY Flashcards
Dose
Total amount of a substance administered to, taken, or absorbed by an organism.
What is a biomarker of dioxin exposure?
Induction of CYP1A4 and CYP1A5
Toxicant
Toxic substances that are produced by or are a by-product of human-made activities.
What is biotransport?
It is when a contaminant is able to move around an ecosystem because it is in an organism. Seabird guano is an example of this.
what is biomethylation
metal biotransformation whereby an ethyl or methyl group is added to a metal
what is selyean stress/general adaptation syndrome?
the non-specific response of the body to extraordinary demands made upon it: alarm, adaptation, exhaustion
what are the light isotopes
C12, N14, S32
What is the most toxic toxicant?
TCDD
What is the typical length of a chronic toxicity test?
Ideally minimum 10% of organism’s lifespan.
Boomerang Paradigm
What you throw away may come back to harm you” DDT, MeHg
What is R0?
net reproductive rate. number of females born to a female in her life time
What are four biological traits the contribute to higher concentrations in predators?
high lipid content, longer lifespan, larger body size, slower growth rates
Xenobiotic
A foreign substance that is not part of the normal biochemistry of the organism.
Define allometry and how it is related to ecotox
the size of an organism influences feeding rate, metabolic rate and thus uptake, biotransformation and elimination processes
what is lx?
age specific survival, proportion surviving to that age class
Mechanism of Action
A set of molecular targets of a drug or contaminant and the receptors and enzymes involved. eg. Acetylcholinesterase inhibitor.
what are two synonyms for biomagnification?
bioamplification and trophic enrichment
What is the formula for bioaccumulation factor?
concentration in organism / concetration in media
(at steady state)
What is the formula for daily dose of exposure?
Concentration in food x food intake rate x area use factors divided by body mass
What is the most toxic toxin?
Botulinum
Contaminant
Chemical or element that exceeds normal background levels; it may or may not cause environmental harm
What is the typical length of an acute toxicity test?
Less than 96 hours.
What is the theory of global fractionation?
most volatile chemicals, such as HCB, HCH, travel to the highest latitudes, while less volatile compounds, such as DDT, are less readily distilled and tend to remain near their source region
Pollutant
Chemical or element that exceeds normal background levels and causes environmental harm.
Bioaccumulation is the net consequence of ____ and ____.
uptake and elimination
what is depuration
the experimental procedure of placing an organism into a clean environment where the contaminant concentration will decrease
Dilution Paradigm
The solution to pollution is dilution
What is the formula for biomagnification factor
= [in organism] / [in diet]
>1 means biomagnifying
<1 means trophic dilution
does bioaccumulation usually increase or decrease with increasing pH?
it usually decreases with increasing pH
What is N15 used to indicate?
its the best indicator of trophic status and marine input. average increase of 3.4% per trophic level
ppm
mg/kg ug/g mg/L
For BCF, which source of accumulation does it exclude? Respiration, dermal, or diet?
Diet
What is phase 1 biotransformation
trying to make compound more hydrophilic by adding functional group
what is the common mode of action in dioxin-like compounds?
mediated by aryl hydrocarbon receptor
Name two chemical properties that contribute to biomagnifcation
persitence and lipophilicity
what is Tc?
Mean generation time