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 incorrect?

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 incorrect 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 incorrect 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 incorrect?

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 incorrect?

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 oxidative decarboxylation of piruvic acid. Krebs cycle

Choose the correct answer:

1. The central metabolic pathway is…..

A. the metabolic pathway characterized converting glucose to pyruvate;

B. the metabolic pathway characterized converting amino acids to pyruvate;

C. the metabolic pathway characterized converting fat acids to pyruvate;

D. the metabolic pathway characterized converting pyruvate or acetyl CoA to end products;

E. the metabolic pathway characterized converting fat acids to acetyl CoA

2. The Pyruvate Dehydrogenase Complex (PDC) consists of following cofactors… Choose the incorrect answer:

A. thiamine pyrophosphate;

B. Co-enzyme A;

C. FAD and NAD⁺;

D. lipoamide;

E. FMN and NADP⁺

3. Which one of the following statements concerning the PDC is incorrect?

A. it is located inside the mitochondria;

B. it converts pyruvate to acetyl CoA;

C. it consists of 3 enzymes;

D. the dephosphorylated form of the pyruvate dehydrogenase is active;

E. NADH and acetyl CoA activate PDC.

4. The PDC is activated by….. Choose the incorrect answer.

A. pyruvate dehydrogenase phosphatase;

B. pyruvate dehydrogenase kinase;

C. pyruvate;

D. Mg²⁺;

E. AMP

5. The PDC is inhibited by….. Choose the incorrect answer.

A. pyruvate dehydrogenase phosphatase;

B. pyruvate dehydrogenase kinase;

C. NADH;

D. acetyl CoA;

E. ATP

6. Which one of the following statements about citric acid cycle is incorrect?

A. it is the final common oxidative pathway where acetyl CoA oxidized to CO₂;

B. it is the source of reduced coenzymes;

C. it provides precursors for synthesis of amino acids and nucleotides;

D. it is located inside the mitochondria;

E. it is located in the cytosol.

7. Acetyl CoA is used to biosynthesis….. Choose the incorrect answer.

A. fatty acids;

B. bile acids;

C. cholesterols;

D. proline;

E. ketone bodies.

8 In the Krebs cycle …… NADH molecules are generated.

A. 0

B. 1

C. 2

D. 3

E. 4

9. In the Krebs cycle …… CO₂ molecules are liberated.

A. 0

B. 1

C. 2

D. 3

E. 4

10.In the Krebs cycle …… FADH₂ molecule is generated.

A. 0

B. 1

C. 2

D. 3

E. 4