Section XVIII Biochemistry of saliva and tooth tissue

1. What substance cause a viscosity of saliva and protect oral mucosa against harmful agents, mechanical damage including ?

1. Mucine

2. Lysozyme

3. Amylase

4. Kallicreine

5. Glucose

2. Parodontitis is accompanied with activation of proteolytic degradation of parodont tissue. The marked increase in content of what substances in oral fluid indicates on activation of proteolysis?

1. Amino acids

2. Biogenic amines

3. Organic acids

4. Glucose

5. Cholesterol

3. Concentration of proton ions in saliva of healthy adults corresponds to pH 6,4-7,8. What process in enamel is favored during shift of salivary pH to acidic side (below pH 6,2)?

A. Surface enamel demineralization

B. Mineralization of enamel surface

C. Increase in resistancy to acids

D. Calcification

E. Fluorosis

4. Normal pH of saliva is 6.4-7.8. The shift of pH to alkaline region (pH 7.8) favors the next process:

A. Deposition of Ca and phosphate ions into surface of enamel

B. Decrease in resistance of tooth tissue to the action of cariesogenic factors

C. Enamel demineralization

D. Release of calcium from tooth tissue

E. Release of phosphate from tooth tissue

5. One of the functions of saliva is a protective function. It consists in formation of local resistance of mucosa toward bacteria due to secretion by parotid glands of the following protein:

A. Secretory IgA

B. Elastine

C. Collagene

D. Fibrinogene

E. Albumin

6. Decrease in activity of what enzyme indicates on the hypofunction of parotid gland?

A. Amylase

B. Glucokinase

C. Maltase

D. Lysozyme

E. Phosphatase

7. What component of saliva is produced in salivary as well as other glands and provides a viscosity to saliva?

A. Mucine

B. Amylase

C. Maltase

D. Hyaluronic acid

E. Phosphates

8. Protective function of saliva is providet by several mechanisms, one of them includes enzyme, which exhibits bactericidal effect by cleavage a polysaccharide complex of cell wall of staphylococci and streptococci. How is called this enzyme?

1. Lysozyme

2. α-Amylase

3. Oligo-1,6-glucosidase

4. Collagenase

5. β-Glucuronidase

9. Mucine is one of the principal constituents of saliva. According its chemical composition it belongs to the next class of conjugated proteins:

1. Glycoproteins

2. Nucleoproteins

3. Phosphoproteins

4. Lipoproteins

5. Metalloproteins

10. There exist a number of factors which change the pH in oral cavity. What consequences have a decrease of pH of oral fluid below 6.4?

1. Enamel deminaralization and caries development

2. Activation of starch breakdown

3. Enhancement of enamel mineralization

4. Lowering of protective properties of oral fluid

5. Deterioration of oral cavity hygiene

11. Note the optimal range of oral fluid pH for favourable mineralization and remineralization of tooth tissue.

1. 7,2-7,4

2. 7,4-7,8

3. 6,4-6,6

4. 6,2-6,0

5. 5,8-6,0

12. What proteins in saliva prevent the precipitation of calcium phosphate salts and support them in a colloidal state?

1. Proline rich proteins of saliva

2. Lyzozyme

3. Blood serum albumin

4. Blood serum globulins

5. Seromucoids

13. It is known, that salivary glands produce several hormones. Which of them favours the mineralization of teeth?

1. Parotin

2. Calcitonin

3. Epidermal growth factor

4. Nerve growth factor

5. Thymocytes transforming factor

14. What ion component of saliva which concentration corresponds approximately to that in blood plasma is the most important in mineralization of tooth tissues?

1. Calcium

2. Sulphate

3. Bicarbonate

4. Phosphate

5. Potassium

15. How is changed mineralization of hard tissues of tooth in patients with salivary stone disease?

1. It is altered proportion of mineral constituents of saliva

2. It is decreased

3. It is increased

4. It is no changes

16. Increase in content of what hormones in saliva characterizes the development of stress reaction in the organism?

1. Cortisol, adrenalin

2. Testosteron, estradiol

3. Parathyroid hormone, calcitonin

4. Thyroid hormones

5. Insulin

17. In enzymes of oral cavity an important protective significance have enzymes, which neutralize free radicals. Indicate these enzymes.

1. Myeloperoxidase and lactoperoxidase

2. Lysozyme and amylase

3. Proteinases and nucleases

4. Hyaluronidase and collagenase

5. Acid and alkaline phosphatases

18. In oral cavity occur initial stages of digestion. What enzyme of oral cavity degrades polysaccharides?

1. Alpha-Amylase

2. Maltase

3. Saccharase

4. Peroxidase

5. Catalase

19. An important significance in mineralization of enamel plays salivary alkaline phosphatase, which provides the following process:

1. Increase of inorganic phosphate concentration in saliva

2. Decrease of calcium concentration in saliva

3. Decrease of inorganic phosphate concentration in saliva

4. Decrease of calcium and phosphate concentration in saliva

5. Decrease the resistance of enamel towards cariesogenic factors

20. For prevention of proteolysis of own proteins salivary glands produce inhibitors of proteinases. Note an inhibitor of proteinases, which is produced in salivary glands.

1. Acid stabile inhibitor of proteinases

2. Alpha-1-antitrypsin

3. Superoxide dismutase

4. Alpha-2-macroglobulin

5. Neuraminidase

21. What type of immunoglobulins is prevailing in saliva and provides local immunity of mucosa layers in oral cavity?

1. IgA

2. sIgA

3. IgE

4. IgG

5. IgM

22. Daily produced amount of saliva depends from age, gender, nutrition etc. In majority of adults it corresponds to the next mean value:

1. 1,5-2,0 L

2. 1,0-1,5 L

3. 0,5-1,0 L

4. 0,3-0,7 L

5. 0,8-1,6 L

23. Mucine is a mixture of glycoproteins of mucinous type, which is secreted by different salivary glands. It fulfils the next function in oral cavity:

1. All answers are correct

2. It makes an envelope for mucose layer of oral cavity and teeth, thus protecting them from damage.

3. Inhibits diffusion of ions into hard tissues of teeth

4. Binds calcium ions

5. Supports buffer properties of oral fluid.

24. Salivary amylase hydrolyses α-1-4 glucosidic bonds in molecules of polysaccharides. What ion is necessary for stabilization of active centre structure in this enzyme?

1. Chloride

2. Calcium

3. Zinc

4. Magnesium

5. Selenium

25. Saliva contains about 50 enzymes, including acid and alkaline phosphatases. What is the significance of phosphatases in physiology of oral cavity?

1. They release inorganic phosphate from phosphorus containing organic substances and favour mineralization of bones and teeth.

2. They are an important protective factor against pathogenic gram-positive bacteria of oral cavity.

3. They change permeability of tissues, including tooth enamel.

4. They possess antioxidant function and protect oral mucosa

5. They inhibit proteolytic cleavage of salivary proteins.

26. In saliva are present proteins which possess antibacterial properties and participate in mineral metabolism.

1. All answers are correct

2. Acidic proline rich proteins

3. Statherins and lactoferrin

4. Cystatins

5. Histatins

27. Antioxidant enzymes in saliva play important protective role in decomposition of reactive oxygen. Find from the list one which belongs to selenium-dependent enzymes.

1. Glutathione peroxidase

2. Superoxide dismutase

3. Catalase

4. Myeloperoxidase

28. Metabolites of TCA cycle plays in the human body range of functions. Which of these metabolites found in saliva (standard 0.002 - 0.02 g /l), is involved in the regulation of blood calcium level and influences the mineralization of teeth?

A. Citrate B. Isocitrate C. Malate D. Fumarate E. α-ketoglutarate

29. An important role in developing of tooth tissues plays parotyn. In which of the following glands it is synthesized?

 A. In the salivary glands B. In the thyroid gland C. In the pancreas D. In the hypothalamus E. In the thyroid gland

30. Saliva contains proteins that play an important role in the oral cavity. What is normal total content of proteins in the liquid?

 A. 2.0 - 5.0 g\l B. 0.15 - 0.25 g\l C. 0.6 - 0.8 g\l D. 2.0 - 4.0 g\lE. 1.0 - 3.25 g\l

31. It is known that phosphoproteins (proteins with postranscriptional modification) are involved in the mineralization of bone and tooth. Phosphoric acid in these proteins is mainly associated with…:

A. Serine

B. Glycine

C. Methionine

D. Glutamate

E. GABA

32. Human body obtains vitamins, macro-and micronutrients with dietary uptake. Dental fluorosis is highly associated with the excess of the next compound?

A. Fluorine

B. Phosphorus

C. Calcium

D. Sodium

E. Potassium

33. Enamel is highly resistant to various mechanical and chemical factors. Synthesis of what component provides the resistance?

A. Fluorapatite

B. Carbonate apatite

C. Chlorine apatite

D. Hydroxyapatite

E. Collagen

34. The strength of tooth tissues depends on the ratio of organic, inorganic compounds and water. Which of the following tissues contain the least amount of water?

A. Enamel

B. Dentine

C. Periodontium

D. Pulp

E. Cement

35. Deposition of mineral salts occurs in the organic matrix of the tooth prior to the accelerated synthesis of one of the following polysaccharides:

A. Chondroitin sulfate

B. Heparin

C. Glycogen

D. Ceratan sulfate

E. Dermatan sulfate

36. Citrate is involved in the mobilization of calcium. What tooth tissue contains the highest concentration of citrate?

A. Dentine

B. Pulp

C. Cement

D. Enamel

E. Epithelium

37. Fluoride enters the human body mainly with water. What concentration of fluoride in water can predict the development of dental caries?

A. Up to 0.5 mg / l

B. Up to 1.0 mg / l

C. Up to 1.5 mg / l

D. Up to 2.0 mg / l

E. Up to 2.5 mg / l

38. Indicate amino acid, essential for the formation of collagen and organic matrix of the tooth.

A. Oxyproline

B. Tyrosine

C. Serine

D. Threonine

E. Homoserine

39. Organic matrix of enamel is represented by a variety of compounds, including proteins. Specific proteins of enamel include...

A. Amelogenin, ameloblastin, enamelin

B. Collagen

C. Elastine

D. Proteoglycans

E. Albumins

40. Formation of organic matrix is one of the stages of enamel mineralization. Name the protein that plays a leading role in this process.

A. Collagen

B. Fibronectin

C. Albumin

D. Globulin

E. Elastin

41. Mineral base of tooth tissue is formed with different apatite crystals. What type of apatite is dominated in the mineral component of tooth tissue?

A. Hydroxyapatite

B. Carbonate apatite

C. Chlorine apatite

D. Fluorapatite

E. Strontium apatite

42. Antioxidant protection of oral mucosa provides a number of enzymes. Select one of them:

A. Superoxide dismutase

B. Cytochrome oxidase

C. Hexokinase

D. Aldolase

E. Glucose-6-phosphatase

43. Proper metabolism of the periodontal tissue requires energy. Specify the way of ATP formation in this tissue.

A. Anaerobic glycolysis

B. Creatine phosphate pathway

C. Oxidative phosphorylation in mitochondria

D. Photosynthetic phosphorylation

E. Oxidation of fatty acids