Practical lesson 3

FREE RADICALS AND ANTI-OXIDANTS. VITAMINS AS ANTIOXIDANTS

Choose the correct answer:

1. A free radical is….:

A. the chemical covalent bond consists of a pair of electrons;

B. a molecule or molecular fragment that contains one or more unpaired electrons in its outer orbital;

C. the completely reduced molecular oxygen;

D. the outermost orbital in an atom;

E. a pair of electron in the outer orbital.

2. Which one of the following reactive oxygen species is in correct?

A. superoxide anion radical;

B. hydrogen peroxide;

C. lactate;

D. singlet oxygen;

E. hydroxyl radical.

3. Important characteristics of the reactive oxygen species are…. Choose the in correct answer.

A. extreme reactivity;

B. long life span;

C. short life span;

D. generation of new reactive oxygen species by chain reaction;

E. damage to various tissues.

4. The free radical scavenger system consists of… Choose the in correct answer.

A. catalase;

B. superoxide dismutase;

C. glutathione peroxidase;

D. glutathione reductase;

E. cytochrome oxidase.

5. What is the selenium dependent enzyme?

A. catalase;

B. superoxide dismutase;

C. glutathione peroxidase;

D. glutathione reductase;

E. cytochrome oxidase.

6. Which one of the following statements about superoxide dismutase is in correct?

A. it is a non-heme protein;

B. is the selenium dependent enzyme;

C. mitochondrial enzyme is manganese dependent;

D. cytoplasmatic enzyme is copper-zinc dependent;

E. superoxide dismutase converts superoxide to hydrogen peroxide.

7. Which one of the following anti- oxidants is not preventive?

A. catalase;

B. glutathione peroxidase;

C. ethylene diamine tetra-acetate;

D. vitamin E;

E. EDTA.

8. Which one of the following anti- oxidants is chain breaking?

A. catalase;

B. glutathione peroxidase;

C. ethylene diamine tetra-acetate;

D. vitamin E;

E. EDTA.

9. Which one of the following anti- oxidants is not used as a therapeutic agent?

A. vitamin E;

B. vitamin C;

C. caffeine;

D. allopurinol;

E. EDTA.

10. Which one of the following statements about tocopherol is in correct?

A. it is a water- soluble vitamin;

B. it is a lipid- soluble vitamin;

C. it is the most powerful natural anti- oxidants;

D. it is the chain breaking anti- oxidant;

E. it can depress leukocyte oxidative bactericidal activity.

PRACTICAL LESSON 4