1. The severity of a toxicant depends, in large part, on the concentration of the
toxicant at its site of action. Which of the following will decrease the amount of
toxicant reaching its site of action?
- excretion via the kidneys.
2. Toxication (or metabolic activation) is the biotransformation of a toxicant to a
more toxic and reactive species. Which of the following is not a reactive
chemical species commonly formed by toxication?
- hydrophilic organic acids.
3. Which of the following is not an important step in detoxication of chemicals?
- formation of redox-active reactants.
4. Regarding the interaction of the ultimate toxicant with its target molecule,
which of the following is false?
- The noncovalent binding of a toxicant to an ion channel irreversibly inhibits
ion flux through the channel.
5. All of the following are common effects of toxicants on target molecules
EXCEPT:
- opening of ion channels.
6. Which of the following proteins functions to prevent the progression of the cell
cycle?
- IκB.
7. Which of the following would have the largest negative impact on intracellular
ATP levels?
- interference with electron delivery to the electron transport chain.
8. What happens when a toxicant induces elevation of cytoplasmic calcium
levels?
- Mitochondrial uptake of calcium dissipates the electrochemical gradient
needed to synthesize ATP.
9. Cytochrome c is an important molecule in initiating apoptosis in cells. All of
the following regarding cytochrome c are true EXCEPT:
- Caspases are proteases that increase cytoplasmic levels of cytochrome c.
10. All of the following regarding DNA repair are true EXCEPT:
- In nucleotide excision repair, only the adduct is cleaved, and the gap is then
filled by DNA polymerase.
11. Apoptosis can serve as a tissue repair process in a number of cell types. In
which of the following cell types would this be a plausible mechanism of tissue
repair?
- gastrointestinal epithelium.
12. Which of the following is NOT associated with carcinogenesis?
- normal p53 function.
toxicant at its site of action. Which of the following will decrease the amount of
toxicant reaching its site of action?
- excretion via the kidneys.
2. Toxication (or metabolic activation) is the biotransformation of a toxicant to a
more toxic and reactive species. Which of the following is not a reactive
chemical species commonly formed by toxication?
- hydrophilic organic acids.
3. Which of the following is not an important step in detoxication of chemicals?
- formation of redox-active reactants.
4. Regarding the interaction of the ultimate toxicant with its target molecule,
which of the following is false?
- The noncovalent binding of a toxicant to an ion channel irreversibly inhibits
ion flux through the channel.
5. All of the following are common effects of toxicants on target molecules
EXCEPT:
- opening of ion channels.
6. Which of the following proteins functions to prevent the progression of the cell
cycle?
- IκB.
7. Which of the following would have the largest negative impact on intracellular
ATP levels?
- interference with electron delivery to the electron transport chain.
8. What happens when a toxicant induces elevation of cytoplasmic calcium
levels?
- Mitochondrial uptake of calcium dissipates the electrochemical gradient
needed to synthesize ATP.
9. Cytochrome c is an important molecule in initiating apoptosis in cells. All of
the following regarding cytochrome c are true EXCEPT:
- Caspases are proteases that increase cytoplasmic levels of cytochrome c.
10. All of the following regarding DNA repair are true EXCEPT:
- In nucleotide excision repair, only the adduct is cleaved, and the gap is then
filled by DNA polymerase.
11. Apoptosis can serve as a tissue repair process in a number of cell types. In
which of the following cell types would this be a plausible mechanism of tissue
repair?
- gastrointestinal epithelium.
12. Which of the following is NOT associated with carcinogenesis?
- normal p53 function.
