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8 Cards in this Set
- Front
- Back
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1. Look at the following data:
Time (hours) Concentration (ug/L) 0 500.00 1 425.00 2 361.25 3 307.06 What is the proportionality constant for this chemical: |
a) 75/hr
b) 0.15/hr c) 6.7/hr d) 0.85/hr e) none of the above (b) (500-425 = 75; 75/500 = .15/hr) |
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2.What is the half life for the chemical in question 1:
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a) 0.00924 hours
b) 4.62 hours c) 0.216 hours d) 0.103 hours e) 0.815 hours b) (.693/.15 = 4.26) by the way, you can check your answer by "eyeballing" the data - notice at 3 hours, there is still just over half the original concentration, so the t1/2 life must be somewhere around 4 hours............... |
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3. A 50 kg woman has 60% of her body weight from water. She is given a
2 mg dose of a chemical that distributes into the extracellular and intracellular water. What concentration will the chemical acheive in the extracellular and intracellular water? |
The intracellular and extracellular water= total body water. This
woman TBW is 60% of her weight or 30 kg. 30 kg of water is equal to 30 litres of water. so the final concentration is 2 mg/30 litres = .067 |
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4. A 100 kg man is 60% water. He is given a 1 mg dose of chemical that
distributes only into the plasma water. What concentration will the chemical acheive in the plasma water? |
4% of the man's weight is the plasma water. So there are 4 kg of
plasma water. This is equivalent to 4 Litres. So the final concentration of chemical in the plasma is 1mg/4 litres = .25 mg/litre |
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5. Which of the following statements is true:
a) the purpose of chemical biotransformation is to make chemicals less toxic b) the major organ of biotransformation is the kidney c) organs such as the skin have some capacity to biotransform d) none of the above |
C
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6. Which of the following statements is true regarding phase 1 and
phase 2 reactions: a) phase 1 reactions are synthetic reactions b) phase 2 reactions lead to the break down of the original compounds c) some chemicals can go directly into a phase 2 reaction d) Phase 2 reactions are either oxidations, reductions or hydrolysis reactions e) none of the above |
C
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7. Which of the following statements is true:
a) The only enzymes in involved in Phase 1 reactions are cytochrome P450's b) Cytochrome P450s catalyze hydrolysis reactions c) cytochrome P450s are a family of enzymes with substrate specificities d) a and b e) b and c |
C
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8. The blood brain barrier only serves to slow down the rates at which
toxicants cross into brain tissue: a) true b) false |
A
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