113. Fill in the blanks.

DNA (strand 1) T G T _ _ _ _ _ _

DNA (strand 2) _ _ A C _ _ _ _ _

mRNA (from strand2) U _ _ _ C A _ _ _

tRNA anticodons _ _ _ _ _ _ G C A

Answer :

DNA (strand 1) T G T G C A C G T

DNA (strand 2) A C A C G T G C A

mRNA (from strand2) U G U G C A C G U

tRNA anticodons A C A C G U G C A

114. Put the numbers of the enzymes on their place in the picture. Using arrows indicate the direction of replication and direction of synthesis of leading and lagging strands.

1 – DNA polymerase

2 – DNA ligase

3 – SSB proteins

4 – topoisomerase

5 – Okazaki fragment

6 – RNA primer

7 - RNA primase

8 – helicase

Answer:

115. Many translation-inhibiting antibiotics work selectively on prokaryotic organisms because the process of translation is sufficiently different in them than it is in humans. That is why translation is a clinically important target of a variety of such drugs. Put antibiotics, inhibitors of translation chloramphenicol, erythromycin, tetracycline, streptomycin into the boxes that indicate their mechanism of action.

Answer:

116. Three possible ways in which DNA can replicate are illustrated. The two original strands of DNA are shown in dark; newly synthesized DNA is light. Choose from the above a semiconservative model of DNA replication, name the rest models.

1 2 3

Original double helix

First round of replication

Second round of replication

Answer: 1 – conservative, 2 – semiconservative, 3 – dispersive.

Section VIII Molecular mechanisms of hormone action on target cells. Biochemistry of hormonal regulation

l. Indicate a substance which serves as a secondary messenger and increase Ca²⁺ ion concentration.

1. Inositol-1,4,5-triphosphate

2. Inositol-3,6-bisphosphate

3. Phosphatidyl-inositol-4,5-bisphosphate

4. Inositol-6-phosphate

5. Free inositol

2. A hormone secreted from anterior pituitary is:

1. Growth hormone

2. Vasopressin

3. Oxytocin

4. Epinephrine

5. Norepinephrine

3. A hormone secreted from posterior pituitary is:

1. Vasopressin

2. Thyrotropic hormone

3. Prolactin

4. Adrenocorticotropic hormone

5. Growth hormone

4. The number of amino acids in human growth hormone is

1. 191

2. 19

3. 151

4. 291

5. 391

8. Acromegaly results due to excessive release of:

1. Growth hormone

2. Insulin

3. Glucagon

4. Thyroxine

5. Oxytocin

5. All of the following are known to be part of a signal transduction cascade EXCEPT:

1. Phosphorylation of fibronectin

2. Dissociation of the components of a heterotrimeric G-protein

3. Enzymatic breakdown of phosphatidyl inositol bisphosphate (PIP₂ )

4. Elevation of intracellular [Ca²⁺]

5. Activation of cGMP phosphodiesterase

6. Ca²⁺ ions constitute one of the most ancient evolutionary second messengers. They are activators of glycogenolisis in case of reacting with:

1. Calmodulin

2. Calcitonin

3. Calciferol

4. Kinase of myosin light chains

5. Phosphorylase C

7. Secondary messengers diacylglycerol and inositol triphosphate are produced from subsequent phospholipid of plasma membrane due to the activity of the following enzyme:

1. Phospholipase C

2. Phospholipase A₁

3. Phospholipase A₂

4. Phospholipase D

5. Phosphodiesterase

8. All of the following are known to be part of a signal transduction cascade EXCEPT:

1. Phosphorylation of fibronectin

2. Dissociation of the components of a heterotrimeric G-protein

3. Enzymatic breakdown of phosphatidyl inositol bisphosphate (PIP₂ )

4. Elevation of intracellular [Ca²⁺]

5. Activation of cGMP phosphodiesterase

9. The receptors of which of the following hormones are not associated with G-protein?

A. Aldosterone

B. TSH

С. Epinephrine

D. Vasopressin

E. Glucagon

10. Adrenalin is water soluble hormone, its effect is mediated by secondary messengers, which are:

A. cAMP

B. NAD

C. ATP

D. Acetylcholine

E. Cytochrome c

11. There are intracellular receptors for which of the following hormones?

A. Thyroxine

B. Folllicle stimulating hormone (FSH)

C. Oxytocin

D. Insulin

E. ACTH

12. cAMP activates which of the following enzymes?

A. Protein kinase A

B. Tyrosine kinase

C. Phospholipase С

D. Phosphodiesterase

E. Adenylyl cyclase

13. Which of the following is not a steroid hormone?

1. ACTH

2. Aldosterone

Cortisol

3. Testosterone

4. Estrogen

14. A patient appealed to the doctor with complaints about tremor and hypokinesia. The biochemical analysis of blood showed the reduced amount of dopamine. Name its methabolite-precursor.

A. Tyrosine

B. Dioxyphenylalanine

C. Tyramine

D. Phenylalanine

E. Phenylpyruvate

15. Thyroxine labeled with 131I is administered to a patient for the purpose of imaging the thyroid gland. The radioactive half-life of the isotope is 8 days. The biological half-life (the time required for half of the compound to be eliminated from the body) is 2 days. The time at which 3/4 of the original radioactivity will no longer be detectable in the body is closest to

1. 3.2 days

2. 2.0 days

3. 4.0 days

4. 4.8 days

5. 16.0 days

16. Endemic goiter is known to be widespread in certain geochemical areas. The deficiency of what chemical element causes this disease?

1. Iodine

2. Iron

3. Zinc

4. Copper

5. Cobalt

17. ACTH induces rise in:

1. Cyclic AMP

2. Cyclic GMP

3. Calcium

4. Magnesium

18. Tetraiodothyronine is produced in the next gland:

1. Follicles of thyroid gland

2. Cortex of adrenals

3. Medulla of adrenals

4. Parathyroid glands

5. Langerhans islands

19. Chose a substance from listed below which inhibits production of thyroxine:

A. 5-fluorouracil

B. Dihydrouracil

C. 5-hydroxyuracil

D. Thiouracil

E. TSH-releasing hormone

20. Calcitonin is hormone of polypeptide nature, which is produced in:

A. Thyroid gland

B. Incretory pancreas

C Parathyroid gland

D .Cortical part of adrenals

E. Hypothalamus

21. Physiological effect of calcitonin is:

A. Lowering of calcium level in blood

B. Decrease of blood glucose level

C. Stimulation of lipogenesis

D. Regulation of water balance

E. Stimulation of smooth muscle contraction

22. During operation on a thyroid gland parathyroid glands were removed by mistake. The patient got titanic cramps. The metabolism of which chemical element was disturbed?

1. Calcium

2. Magnesium

3. Potssium

4. Iron

5. Sodium

23. Physiological effect of parathyroid hormone (PTH) is as follows:

A. Increase of calcium level in blood

B. Stimulation of protein synthesis

C. Lowering of blood glucose level

D. Decrease of calcium level in blood

E. Lipid mobilization

24. The number of amino acids in the hormoneoxytocin is:

1. 9

2. 7

3. 14

4. 18

5. 20

25. Parathyroid hormone (PTH):

A. Is a polypeptide

B. Is a derivative of amino acid tryptophan

C. Is substance of steroid structure

D. Is derivative of N-acetyl-galactosamine

E. Exhibits properties of polysaccharide

26. Utilization of glucose occurs by means of sugar transport from the extracellular matrix through the plasma membrane membrane into the cell. What hormone stimulates this process?

1. Insulin

2. Glucagon

3. Thyroxine

4. Aldosterone

5. Adrenaline

27. In patient S. blood glucose level is 10 mmoles/l, polyuria, glucosuria and ketonuria are observed. What pathological state can be suggested?

A. Diabetes mellitus

B. Starvation

C. Hypercorticism

D. Addison disease

E. Hyperthyreosis

28. Glucagon is produced in the next endocrine gland:

A. Langerhans islands, α cells

B. Parathyroid gland

C. Pitiutary gland

D. Thymus

E. Medullar part of adrenals

29. Adrenalin is a hormone, which is produced in:

A. Medullar part of adrenals

B. Langerhans islands, β cells

C. Cortical part of adrenals

D. Hypophysis

E. Thymus

30. Destruction of pancreatic islets of Langerhans results in the decrease of production of:

1. Glucagon and insulin

2. Parathhormone and cortisone

3. Thyroxyne and calcitonin

4. Insulin and adrenaline

5. Callicrein and angiotensin

31. The next enzyme is involved in the production of leukotriens from arachidonic acid:

A. Cyclooxygenase

B. Monooxygenase

C. Dioxygenase

D. Lipoxygenase

E. Catalase

32. TSH stimulates the synthesis of:

1. Thyroxine

2. Adrenocorticoids

3. Epinephrine

4. Insulin

5. Glucagon

33. Cyclooxygenase catalyzes the synthesis of which of the following compounds?

A. Prostaglandines

B. Cyclic AMP

C. Leucotriens

D. Porphobilinogen

E. Cyclic GMP

34. The activity of cyclooxygenase can be suppressed by some medical preparations. What preparation exhibits irreversible inhibitory action upon this enzyme?

A. Acetylsalicylic acid

B. Insulin

C. Allopurinol

D. Oligomycine

E. Aminalone

35. Leucotriens are humoral factors, produced by leukocytes using as a precursor:

A. Arachidonic acid

B. Nicotinic acid

C. Pantothenic acid

D. Homogentisic acid

E. Ascorbic acid

36. Thyroid hormones are synthesized by the iodination of the amino acid:

1. Glycine

2. Phenylalanine

3. Alanine

4. Tyrosine

5. Valine

37. Glucagon:

1. Stimulates muscle glycogenolysis

2. Increases protein synthesis

3. Inhibits lipolysis in adipocytes

4. Increases gluconeogenesis in liver

38. What hormone stimulates the reabsorption of water in kidney tubules?

A. Vasopressin

B. Parathyroid hormone (PTH)

C. Calcitonin

D. Aldosterone

E. Atrial natriuretic peptide (ANP)

39. The primary action of steroid hormones is at the level of:

1. Transcription

2. RNA export from the nucleus

3. Pre-mRNA splicing

4. mRNA degradation

5. Gene rearrangement

40. The principal site of peptide neurohormone biosynthesis is the:

1. Rough endoplasmic reticulum

2. Nucleus

3. Dendrite

4. Postsynaptic density

5. Synaptic vesicle

41. A hormone response element is best defined by which one of the following statements?

1. It is the DNA sequence to which a specific hormone-receptor complex binds

2. It is transmembrane protein to which steroid hormones bind

3. It is a DNA sequence to which steroid hormones bind

4. It is the region of a steroid hormone receptor to which the hormone binds

5. It is plasma protein that carries a specific lipophilic hormone through the bloodstream

42. What endocrine gland produces hormones regulating mineral elements turnover?

1. Posterior pituitary

2. Suprarenal glands

3. Pancreatic gland

4. Ovary

5. Anterior pituitary

43. Aldosteron regulates the next physiological process:

1. Reabsorption of sodium ions in exchange to potassium ions in renal tubules

2. Stimulation of gluconeogenesis

3. Stimulation of sodium excretion with urine

4. Stimulation of lipolysis and oxidation of fatty acids

5. Reabsorption of glucose in convoluted tubules

44. The next substance is a precursor of progesterone:

1. Cholesterol

2. Cholic acid

3. Cholecalciferol

4. Phenylalanine

5. Glutathion

45. G-proteins act as:

1. Hormone carriers

2. Hormone receptors

3. Second messengers

4. Signal transducers

46. During the operation on a thyroid gland parathyroid glands were removed by mistake. The patient got tetanic cramps. The metabolism of which chemical element was disturbed?

A. Calcium

B. Magnesium.

C. Potassium.

D. Iron.

E. Sodium

47. In the human organism the some amino acid are transformed into hormones. In what compound tryptophan transforms in?

A. Serotonin

B. Histamine

C. GABA

D. Corticosteron

E. -alanine

48. After a brain hemorrhage that led to the damage of hypotalamic nuclei, diabetes insipidus of a 67-year-old patient developed. What became the reason of polyuria in this case?

A. Decrease of water reabsorbtion

B. Decrease of potassium ions reabsorbtion.

C. Acceleration of glomerular filtration.

D. Hyperglycemia.

E. Hypoglycemia.

49. Graves disease is caused by dysfunction of the following endocrine gland:

1. Hyperthyreosis

2. Adrenocortex hyperfunction

3. Adrenocortex hypofunction

4. Hypothyreosis

5. Hyperproduction of ACTH

50. Cushing’s disease, which is characterized by obesity, hypertension and elevated blood glucose level, is caused by disorder in production and secretion of the next hormones:

1. ACTH and glucocorticoids overproduction

2. Insulin insufficiency

3. ACTH and glucocorticoids insufficiency

4. Thyroxine insufficiency

5. Estriol overproduction

51. Melanocyte stimulating hormone is secreted by:

A. Intermediate lobe of pituitary gland

B. Anterior lobe of pituitary gland

C. Posterior lobe of pituitary gland

D. Pineal gland

E. Thyroid gland

52. Addison’s disease is a severe disorder of sodium-potassium turnover due to failure in production of the following hormone:

1. Aldosterone

2. Thyroxine

3. Triiodothyronine

4. Testosterone

5. Progesterone

53. Cretinism is caused by the next inborn endocrine disorder:

1. Inborn and persistent hypofunction of thyroid gland

2. Hyperproduction of ACTH by tumor of adenohypophysis

3. Inborn hypofunction of adrenal cortex

4. Inborn hypersecretion of glucocorticoids

5. Underdevelopment of thymus

54. Myxoedema is manifested in adults due to the next endocrine disorder:

1. Severe hypoparathyroidism

2. Severe hypothyroidism

3. Insufficiency of ACTH secretion

4. Underproduction of corticosteroids

5. Hyperproduction of corticosteroids

55. Some hormone induce uncoupling of respiration and oxidative phosphorylation in mitochondria and lower the efficiency of ATP production. What is this hormone?

1. Thyroxine

2. Adrenalin

3. ACTH

4. Oxytocine

5. Testosterone

56. Note from listed below hormones a pricipal representative of mineralocorticoids.

1. Aldosterone

2. Corticosterone

3. Hydrocortisone

4. Dihydrocorticosterone

5. Estradiol

57. The next compounds are the end products of steroid hormones catabolism, excreted with urine.

1. 17-ketosteroids, conjugated with sulfuric acid

2. Progesterone conjugated with sulfuric acid.

3. Deoxycorticosterone acetate

4. Hydroxymandelic acid

5. Taurodeoxycholic acid

58. Chose from listed hormones a one with the most potent anti-inflammatory activity:

1. Cortisol

2. Aldosterone

3. Testosterone propionate

4. Megesterol

5. Progesterone

59. The next substance is a precursor of progesterone:

A. Cholesterol

B.Cholecalciferol

C. Cholic acid

D.Phenylalanine

E.Glutathion

60. In human body some amino acids are transformed into hormones. What compound is produced from tryptophan?

A. Serotonin

B. Histamine

C. GABA

D. Corticosteron

E. -alanine

61. How does glucocorticoids influence on the carbohydrate methabolism in a liver?

A. Stimulate gluconeogenesis

B. Stimulate glycogenesis from glucose

C. Stimulate glycogen hydrolysis

D. Stimulate glycogen phosphorolysis

E. Stimulate activity of glycogenphosphorylase

62. Cyclic AMP is formed from ATP by the enzyme adenylate cyclase which is activated by the hormone:

1. Insulin

2. Epinephrine

3. Testosterone

4. Progesterone

5. Aldosterone