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Essential Biochemistry - Free Radicals And Antioxidants (Section 1)

1
The main biological targets for attack by free radicals are, except:
Answer
(D)
Glycosaminoglycans
2
Which of the following can be damaged by free radicals?
Answer
A
B
C
3
All of the following are antioxidant except:
Answer
(D)
Phylloquinone
4
What type of antioxidant system includes enzymes?
Answer
(C)
Enzymatic antioxidant system
5
Which of the following vitamins has antioxidant activity?
Answer
(D)
All of the above
6
What is the role of catalase?
Answer
(B)
Converts hydrogen peroxide to water and oxygen
7
What is the result of damage to DNA by free radicals?
Answer
(A)
Mutation
8
The minerals function as antioxidants, except:
Answer
(A)
Manganese
9
What type of reaction does the enzyme mono-oxygenases catalyze?
Answer
(B)
Incorporation of one atom of oxygen into the substrate
10
Enzymes that destroy the superoxide radical and H2O2 are:
Answer
(D)
All the above
11
What are the components that protect the body against toxic effect of free radicals?
Answer
(C)
Antioxidants
12
Which enzyme system is involved in the formation of superoxide?
Answer
(B)
Xanthine oxidase
13
Which of the following is a consequence of the production of ROS?
Answer
A
B
C
D
14
What is the role of reduced glutathione in the antioxidant system?
Answer
(B)
It reduces hydrogen peroxide and lipid hydroperoxides.
15
What is the role of vitamin E in the antioxidant system?
Answer
(D)
All of the above
16
Enzyme responsible for respiratory burst is:
Answer
(A)
NADPH-oxidase
17
Which is an example of a functional free radical?
Answer
(C)
Nitric oxide
18
What is oxidative stress?
Answer
(D)
Both b and c
19
α-Tocopherol prevents rancidity by virtue of this property:
Answer
(A)
Antioxidant
20
Which of the following is NOT a type of antioxidant system?
Answer
(D)
Protein antioxidant system
21
Which of the following are the most important radicals derived from molecular oxygen and nitric oxide?
Answer
(D)
All of the above
22
What is the role of myloperoxidase (MPO) in the respiratory burst?
Answer
(B)
Converts hydrogen peroxide plus chloride ions into hypochlorous acid
23
Which of the following molecules is/are often byproducts of reactions generating free radicals?
Answer
A
B
C
D
24
During respiratory burst, all the following ROS are formed, except:
Answer
(D)
Nitric oxide
25
What is the role of selenium in the antioxidant system?
Answer
(A)
It is required for the activity of glutathione peroxidase.
26
During respiratory burst, all the following ROS are formed, except:
Answer
A
B
C
27
Free radicals are:
Answer
(A)
Chemical species with unpaired electron
28
Which of the following is the most important biological target attacked by free radicals?
Answer
A
B
C
29
α-Tocopherol prevents rancidity by virtue of this property:
Answer
(A)
Antioxidant
30
Which of the following can be caused by genetic deficiencies of NADPH oxidase system?
Answer
(B)
Chronic granulomatous disease
31
Which of the following is an intracellular signaling molecule?
Answer
(B)
Nitric oxide (NO)
32
Which of the following is true about the action of antioxidants?
Answer
A
B
C
33
Which of the following is a characteristic of free radicals?
Answer
(B)
Have a tendency to lose an electron
34
What is a primary source of free radicals in the body?
Answer
(C)
Cellular metabolism
35
Which of the following is involved in the formation of ROS?
Answer
(D)
All of the above
36
Free radicals are:
Answer
(A)
Chemical species with unpaired electron
37
Which of the following is a type of antioxidant system?
Answer
(D)
All of the above
38
What is the role of the enzyme glutathione peroxidase?
Answer
(B)
Reduces hydrogen peroxide and lipid hydroperoxides
39
What is the role of superoxide dismutase (SOD)?
Answer
(A)
Converts superoxide to hydrogen peroxide
40
Which of the following are environmental factors responsible for the generation of harmful free radicals?
Answer
A
B
C
41
Free radicals are:
Answer
(C)
Atoms or molecules with an unpaired electron.
42
Free radicals are:
Answer
(A)
Chemical species with unpaired electron
43
Which of the following is a type of antioxidant system?
Answer
(D)
All of the above
44
Which of the following is a good source of antioxidants?
Answer
(B)
Fresh fruits and vegetables
45
Which vitamin is a powerful antioxidant?
Answer
(C)
Vitamin E
46
What is the role of Glutathione Peroxidase?
Answer
(A)
Converts hydrogen peroxide to water
47
Which of the following is NOT a type of antioxidant?
Answer
(D)
Lipids
48
During respiratory burst, all the following ROS are formed, except:
Answer
(D)
Nitric oxide
49
Enzyme responsible for respiratory burst is (in NADPH-oxidase)
Answer
(A)
NADPH-oxidase
50
What is the role of Superoxide Dismutase (SOD)?
Answer
(A)
To convert superoxide to hydrogen peroxide