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Essential Biochemistry - Detoxification (metabolism Of Xenobiotics) (Section 1)

1
Which of the following is an example of a compound reduced and detoxified by the liver?
Answer
(A)
Aldehydes
2
What is the most common example of conjugation of benzoic acid?
Answer
(A)
Conjugation with glycine
3
Which of the following is a substrate for conjugation with Glutamine?
Answer
(A)
Phenylacetate
4
Phase I reactions primarily involve:
Answer
(B)
Oxidation, reduction, and hydrolysis
5
All of the following compounds are detoxified by sulfation, except:
Answer
(D)
Benzoic acid
6
Which enzyme is involved in the hydroxylation of xenobiotics?
Answer
(B)
Monooxygenase
7
The main goal of the biotransformation process is to convert lipophilic compounds to:
Answer
(B)
More polar, water-soluble forms
8
Which of the following are characteristic of Phase I reactions?
Answer
A
B
9
What is the primary purpose of Phase II reactions?
Answer
(B)
To convert xenobiotics into more polar, water-soluble forms
10
Which of the following is a product of the oxidation of methanol?
Answer
(B)
Formic acid
11
What are the essential products of Phase II reactions?
Answer
A
B
C
12
Which enzyme catalyzes the formation of glucuronide conjugates?
Answer
(B)
UDP-glucuronosyl transferase
13
Which phase is often described as biotransformation?
Answer
(C)
Both
14
What is the role of Rhodanase?
Answer
(B)
To convert cyanides to thiocyanate
15
What are the primary reactions involved in phase I of detoxification?
Answer
A
B
C
16
Which molecules can be methylated?
Answer
A
B
C
D
17
Which compound acts as a sulfur donor in sulfation reactions?
Answer
(C)
Phosphoadenosyl phosphosulfate (PAPS)
18
Which of the following is NOT a Phase II reaction?
Answer
(C)
Oxidation
19
Which of the following are involved in phase II reactions?
Answer
(A)
Conjugation
20
Which molecules participate in conjugation reactions?
Answer
A
B
C
D
21
Which of the following is an example of conjugation?
Answer
(C)
Conjugation of benzoic acid with glycine
22
Which compound is a substrate for conjugation with glycine?
Answer
(A)
Benzoic acid
23
Toxic cyanides are conjugated with:
Answer
(D)
Thiosulfate
24
Which of the following are examples of conjugating agents?
Answer
A
B
C
D
25
Which types of compounds can be formed by acetylation?
Answer
(A)
Mercapturic Acids
26
Which of the following is a common reaction in Phase I metabolism?
Answer
(C)
Hydrolysis
27
All of the following are true for cytochrome P450, except:
Answer
(D)
Is an allosteric enzyme
28
Which metal is detoxified by British antilewisite (BAL)?
Answer
(C)
Mercury
29
Which of the following is NOT a common route of entry for xenobiotics into the human body?
Answer
(D)
Osmosis
30
All of the following are detoxifying agents, except:
Answer
(D)
Glycogen
31
What is the name of the compound that removes heavy metals?
Answer
(B)
British Antilewisite (BAL)
32
Which of the following is a common conjugating agent used in Phase II reactions?
Answer
(C)
Glutathione
33
Which of the following is an example of a Phase I reaction?
Answer
(C)
Hydroxylation
34
What is the role of monooxygenases (mixed-function oxidases)?
Answer
(B)
To catalyze the oxidation of xenobiotics
35
Which of the following is a xenobiotic that undergoes conjugation with glutathione?
Answer
A
B
C
D
36
Which enzyme is involved in conjugation with glutathione?
Answer
(B)
Glutathione S-transferase
37
Which process is involved in the oxidation of aromatic hydrocarbons to phenols?
Answer
(B)
Hydroxylation
38
Which of the following is an example of a drug undergoing acetylation?
Answer
(A)
Sulfanilamide
39
Biotransformation by oxidation is catalyzed by:
Answer
(D)
Cytochrome P450
40
What is the general purpose of the two phases of xenobiotic metabolism?
Answer
(A)
To increase water solubility and facilitate excretion
41
What is the result of oxidation of aromatic hydrocarbons?
Answer
(B)
Phenols
42
What is the name of the process that involves the addition of a glucuronic acid molecule to a xenobiotic?
Answer
(B)
Glucuronidation
43
What enzyme catalyzes the formation of glucuronide conjugates?
Answer
(B)
UDP-glucuronyl transferase
44
Which is a typical reaction in phase I reactions?
Answer
A
B
C
45
Where is the cytochrome P450 found?
Answer
(C)
Endoplasmic reticulum
46
All of the following are true for cytochrome P450 except:
Answer
(D)
Is an allosteric enzyme
47
Which of the following is a Phase I reaction?
Answer
(C)
Oxidation
48
What are the functions of phase II reactions?
Answer
(D)
All the above
49
What is the purpose of Phase II reactions?
Answer
A
B
C
D
50
What is the role of methylation in detoxification?
Answer
(D)
To change the structure of the xenobiotic