Intro and Physiochemical Properties Flashcards
Often the most informative classification of toxic agents is based on ___________
biochemical mode of action.
Why are active ingredients mixed with inert ingredients in pesticide formulations?
To increase the ease of application and shelf-life.
What is toxicology?
The study of the adverse effects of chemical agents on biological systems.
What is acute toxicity?
short-term exposure of a single dose or repeated doses for periods of less than 24 hours.
What is chronic toxicity?
repeated exposure for long periods of time.
What is chronic toxicity?
epeated exposure for long periods of time.
About how many insect species are considered pests that consume crops or spread diseases?
10,000
what are the most commonly used pesticides?
Herbicides.
How much global food production is estimated to be lost to pests?
20-40%
What is the term for the highest dosage administered that does not produce toxic effects?
No Observable Effect Level (NOEL)
What are the major factors that influence toxicity as it relates to exposure?
- Duration
- Frequency of Exposure
- Route of administration
Which of the following are the three interrelated elements of toxicology?
- Biological system
- Chemical agent
- Deleterious response
What is ionization largely dependent upon?
pH
Two general characteristics of organochlorines/chlorinated hydrocarbons?
- Chemical stability
- Extreme lipophilicity and apolarity
What is the definition of adsorption?
The adhesion of atoms, ions, or molecules to a surface.
Which was the first successful neonicotinoid with a number of structural derivatives currently on the market?
Imidacloprid
In an insecticide bioassay, why is it important to report the conditions (temperature, lighting, source of insects, etc.) of the experiment?
Because these conditions can impact the LD50 and LC50
What is the definition of LD50?
The amount of poison per unit body weight which will kill 50% of the population being tested
What are the three physical/chemical properties important to a compound’s toxicity?
- Solubility
- Adsorption
- Ionization
In solubility, what determines if two substances are alike?
- Dipole moment
- Electron affinity
- Polarity
What is responsible for getting a toxin to the target site and/or metabolic enzyme?
Physical properties
What governs action at the site and metabolic stability?
Chemical properties
Two subclasses of organophosphates?
- Phosphorothioates
- True phosphates
What are the three assumptions regarding response?
- A quantifiable method for measuring response is available
- Response results from the chemical
- Response is related to the dose administered
what is a bioassay?
Any experiment in which a living organism is used as a test subject.
