Quick Biochemistry - Hormone Metabolism (Section 4)

  • 1
    The location of the nucleotide binding site on G-proteins is on their
    Răspuns
    (A)
    a-Subunit
  • 2
    Adenylate cyclase is stimulated by
    Răspuns
    (B)
    GTP-bound a-Subunit of G-protein
  • 3
    Which of the following receptors exhibits tyrosine kinase activity?
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    (D)
    Insulin receptors
  • 4
    The insulin receptor exists as a
    Răspuns
    (D)
    Tetramer
  • 5
    Which receptor demonstrates tyrosine kinase activity?
    Răspuns
    (B)
    PDGF receptor
  • 6
    The activation of Protein kinase C is triggered by
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    (C)
    Diacyl glycerol
  • 7
    Where is melatonin produced?
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    (C)
    Pineal gland
  • 8
    Melatonin is derived from
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    (C)
    Tryptophan
  • 9
    The secretion of Melanocyte stimulating hormone originates in the
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    (D)
    Intermediate lobe of pituitary gland
  • 10
    What effect does MSH have?
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    (B)
    Increase in melanin concentration in melanocytes
  • 11
    What mechanism governs the release of MSH?
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    (C)
    Hormones from the hypothalamus
  • 12
    Which hormone is produced within the hypothalamus?
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    (C)
    Antidiuretic hormone
  • 13
    What hormone is released by the rear pituitary gland?
    Răspuns
    (B)
    Oxytocin
  • 14
    Which of these choices represents a nonapeptide?
    Răspuns
    (A)
    Antidiuretic hormone
  • 15
    A shortage of which hormone leads to diabetes insipidus?
    Răspuns
    (C)
    Vasopressin
  • 16
    What substance, in high amounts, leads to blood vessel constriction in the body's periphery?
    Răspuns
    (A)
    Antidiuretic hormone
  • 17
    Where is somatotropin produced?
    Răspuns
    (B)
    Frontal pituitary
  • 18
    What substance promotes the release of Insulin-like Growth Factor-l?
    Răspuns
    (C)
    Growth hormone
  • 19
    Growth hormone enhances
    Răspuns
    (A)
    Protein formation
  • 20
    The release of growth hormone is reduced by
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    (B)
    Somatostatin
  • 21
    Which substance stimulates the release of somatotrophin?
    Răspuns
    (C)
    Growth hormone releasing hormone
  • 22
    What is the structure of human growth hormone?
    Răspuns
    (B)
    One polypeptide chain and two intra-chain disulphide bond
  • 23
    How many amino acid residues are present in human growth hormone?
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    (C)
    191
  • 24
    How many amino acid residues are present in prolactin?
    Răspuns
    (D)
    198
  • 25
    The secretion of prolactin is controlled by which of the following?
    Răspuns
    (C)
    Prolactin release inhibiting hormone
  • 26
    Which molecule is the precursor of ACTH?
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    (D)
    Pro-opiomelanocortin
  • 27
    Which of the following is NOT a product of pro-opiomelanocortin?
    Răspuns
    (D)
    FSH
  • 28
    Which statement about pro-opiomelanocortin is incorrect?
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    (C)
    It is the precursor of ACTH and melatonin
  • 29
    Which statement about ACTH is false?
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    (D)
    Its second messenger is inositol triphosphate
  • 30
    What mechanisms regulate ACTH secretion?
    Răspuns
    (C)
    CRH and feedback inhibition by cortisol
  • 31
    ACTH is composed of how many amino acids?
    Răspuns
    (A)
    39
  • 32
    CRH is composed of how many amino acids?
    Răspuns
    (B)
    41
  • 33
    The hormonal function of ACTH is completely lost if which of the following is removed?
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    (D)
    None of these
  • 34
    Which statement regarding TSH is incorrect?
    Răspuns
    (D)
    Its subunit is identical with those of FSH and LH
  • 35
    Which of the following statements about TSH is false?
    Răspuns
    (B)
    It acts on para-follicular cells of thyroid glands
  • 36
    Which statement about thyrotropin releasing hormone is not true?
    Răspuns
    (B)
    It is a pentapeptide
  • 37
    In males, where does luteinizing hormone have its effect?
    Răspuns
    (A)
    Leydig cells
  • 38
    Which of the following statements concerning FSH is not correct?
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    (D)
    It increases the synthesis of testosterone
  • 39
    In males, which of the following inhibits the release of luteinizing hormone?
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    (C)
    High blood level of testosterone
  • 40
    What factor stimulates the release of luteinizing hormone?
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    (A)
    GnRH
  • 41
    What hormone does HCG's structure and function most closely resemble?
    Răspuns
    (B)
    LH
  • 42
    What condition is a consequence of excessive production of a specific hormone in adulthood?
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    (D)
    Growth hormone during adult life
  • 43
    Which of the following is NOT a result of acromegaly?
    Răspuns
    (B)
    Increased stature
  • 44
    Excessive growth hormone production during youth leads to which condition?
    Răspuns
    (B)
    Gigantism
  • 45
    A reduced secretion of a certain hormone during childhood is associated with which condition?
    Răspuns
    (C)
    Dwarfism
  • 46
    Which condition is characterized by an increase in height?
    Răspuns
    (A)
    Gigantism
  • 47
    Which amino acid serves as a precursor for thyroid hormone synthesis?
    Răspuns
    (A)
    Tyrosine
  • 48
    What enzyme is essential for the production of thyroid hormones?
    Răspuns
    (C)
    Thyroperoxidase
  • 49
    Which substance does thyroperoxidase act upon to introduce iodine?
    Răspuns
    (B)
    Tyrosine residues of thyroglobulin
  • 50
    At which positions are tyrosine residues iodinated in the thyroxine molecule?
    Răspuns
    (C)
    3 and 5