Question 1

Hypothalamic hormones which regulate the synthesis and secretion of anterior pituitary hormones include all of the following EXCEPT

Accepted Answer

A)   TRH (thyrotropin releasing hormone) 
B)   GnRH (gonadotropin releasing hormone) 
C)   somatomedin c
D)   somatostatin
E)   CRH (corticotrophin releasing hormone) F) B) and C)
G) All of the above C

Question 2

Progesterone receptor

Accepted Answer

A)   can bind to DNA in the absence of progesterone
B)   can be activated in the absence of progesterone by phosphorylation
C)   binds to heat shock proteins in the cytoplasm
D)   contains a nuclear localization signal
E)   all of the aboveF) A) and E)
G) C) and D)

Question 3

Which vitamin is a secosteroid and acts through a steroid receptor?

Accepted Answer

A)   Vitamin A
B)   Vitamin C
C)   vitamin D
D)   Vitamin E
E)   Vitamin KF) B) and D)
G) A) and B)

Question 4

Vitamin D, (cholecalciferol)  is converted into

Accepted Answer

A)   1,25-dihydroxycholecalciferol in the kidney.
B)   1-hydroxycholecalciferol in the liver.
C)   25-hydroxycholecalciferol in the kidney.
D)   1,25-dihydroxycholecalciferol in the liver.
E)   25-hydroxycholecalciferol in the liver.F) C) and E)
G) A) and E)

Question 5

Vitamin D may well be considered a hormone because it

Accepted Answer

A)   operates via the second messenger route.
B)   is strictly steroid in nature.
C)   is formed de novo in the body, albeit with the aid of light.
D)   is soluble in lipid solvents.
E)   requires modification in order to express physiological activity.F) None of the above
G) B) and E)

Question 6

Which one of the following statements concerning the formation of estrogens is FALSE?

Accepted Answer

A)   Androgens can be converted to estrogens in adipose tissue.
B)   NADPH and oxygen are required.
C)   The conversion of androgens to estrogens involves the aromatization of the "A" ring and the loss of two methyl groups.
D)   Testosterone can be a precursor of estrogens.
E)   The placenta can convert DHEA-sulfate into estrogens.F) A) and E)
G) B) and D)

Question 7

One of the main functions of mineralocorticoids is to regulate while one of the main functions of the glucocorticoids is to regulate .

Accepted Answer

A)   response to stress, blood pressure
B)   urine output, renin activity
C)   carbohydrate metabolism, salt balance
D)   blood pressure, salt balance
E)   salt balance, carbohydrate metabolismF) C) and D)
G) All of the above

Question 8

Estriol is found in the urine conjugated with

Accepted Answer

A)   glycine.
B)   taurine.
C)   benzoic acid.
D)   protein.
E)   glucuronic acid.F) A) and B)
G) A) and C)

Question 9

Human growth hormone (HGH) , in vivo, in specific tissues

Accepted Answer

A)   Causes an increase in the size of cells.
B)   Causes a decrease in the size of cells.
C)   increases the rate of cell proliferation.
D)   decreases the rate of cell proliferation.
E)   Can be replaced therapeutically by other mammalian growth hormones.F) A) and B)
G) A) and C)

Question 10

High levels of insulin and LDL have identical regulatory effects on the number of their respective cell surface receptors expressed by a cell. For both of these ligand-receptor systems this phenomenon is classified as

Accepted Answer

A)   homologous up-regulation.
B)   homologous down-regulation.
C)   heterologous up-regulation.
D)   heterologous down-regulation.
E)   none of the above.F) B) and E)
G) A) and B) B

Question 11

Which of the following enzymes is involved in the metabolism (breakdown)  of epinephrine?

Accepted Answer

A)   Phenylethanol amine-N-methyl transferase
B)   Catechol-o-methyl transferase
C)   Dopamine-beta-hydroxylase
D)   Aromatic decarboxylase
E)   Cyclic AMP phosphodiesteraseF) A) and E)
G) A) and D)

Question 12

The catabolism and excretion of steroid hormones

Accepted Answer

A)   occurs primarily as the bile salts.
B)   usually involves transmethylation reactions.
C)   requires reduction and cleavage of the steroid nucleus.
D)   may involve conjugation of a metabolite with sulfate or glucuronate.
E)   produces carbon dioxide.F) C) and D)
G) A) and B)

Question 13

The phosphorylation of tyrosine residues on a growth factor receptor

Accepted Answer

A)   generates interaction sites for SH2 domains on target proteins.
B)   is a means of desensitizing the receptor.
C)   leads to the covalent attachment of the growth factor to its receptor.
D)   permits the processing of the growth factor to its active secreted form.E) A) and C)
F) B) and D)

Question 14

ACTH has all of the following effects on the adrenal cortex EXCEPT which one?

Accepted Answer

A)   increased blood flow
B)   depletion of cholesterol esters
C)   development of adrenal hypertrophy
D)   increased activity of the desmolase complex
E)   preferential synthesis of progesteroneF) All of the above
G) D) and E)

Question 15

A peptide hormone which is located both in the hypothalamus and in the pancreas is

Accepted Answer

A)   cholecystokinin
B)   proinsulin
C)   somatostatin
D)   neurophysin
E)   none of the aboveF) None of the above
G) B) and C)

Question 16

Aldosterone

Accepted Answer

A)   would circulate in the blood primarily as the free hormone.
B)   binds to a cytoplasmic protein receptor and is transported to the nucleus of its target cell.
C)   is released from the adrenal cortex by ACTH.
D)   results in the activation of certain enzymes by stimulating their phosphorylation.
E)   results in increased glucose in the blood.F) A) and C)
G) D) and E)

Question 17

Hormones affect the rates of metabolic pathways by all of the following EXCEPT

Accepted Answer

A)   forming covalent bonds with intermediates in metabolic pathways
B)   stimulating uptake of metabolites by cells
C)   stimulating the genome to produce specific transcripts
D)   activating protein kinases
E)   binding to specific receptorsF) All of the above
G) A) and E)

Question 18

Which of the following is a major mineralocorticoid in man?

Accepted Answer

A)   cortisol
B)   corticosterone
C)   aldosterone
D)   androsterone
E)   vasopressinF) C) and D)
G) D) and E) C

Question 19

The insulin? receptor has in common with other growth?
Factor receptors such as epidermal growth factor

Accepted Answer

A)   the ability to phosphorylate tyrosine residues on certain proteins.
B)   the ability to phosphorylate serine residues on certain proteins.
C)   their location in the cytosol.
D)   the ability to bind steroid hormones.
E)   the presence of a bound GTP.F) B) and E)
G) B) and C)

Question 20

As regards the synthesis of ACTH, which of the following statements, if any, is false?

Accepted Answer

A)   It is initially synthesized as proopiomelanocortin (POM
C)  .
B)   Glycosylated POMC is proteolytic ally cleaved into two proteins, Pro-ACTH and Beta-LPH.
C)   Beta-LPH is proteolytic ally cleaved with one of the products being the endorphins.
D)   Pro-ACTH is proteolytically cleaved into ACTH and another protein of unknown function.
E)   None of the above.F) D) and E)
G) All of the above

Exam 22: Biochemistry of Hormones

Hypothalamic hormones which regulate the synthesis and secretion of anterior pituitary hormones include all of the following EXCEPT

Correct AnswerverifiedC

Progesterone receptor

Correct AnswerverifiedShow Answer

Which vitamin is a secosteroid and acts through a steroid receptor?

Correct AnswerverifiedShow Answer

Vitamin D, (cholecalciferol) is converted into

Correct AnswerverifiedShow Answer

Vitamin D may well be considered a hormone because it

Correct AnswerverifiedShow Answer

Which one of the following statements concerning the formation of estrogens is FALSE?

Correct AnswerverifiedShow Answer

One of the main functions of mineralocorticoids is to regulate while one of the main functions of the glucocorticoids is to regulate .

Correct AnswerverifiedShow Answer

Estriol is found in the urine conjugated with

Correct AnswerverifiedShow Answer

Human growth hormone (HGH) , in vivo, in specific tissues

Correct AnswerverifiedShow Answer

High levels of insulin and LDL have identical regulatory effects on the number of their respective cell surface receptors expressed by a cell. For both of these ligand-receptor systems this phenomenon is classified as

Correct AnswerverifiedB

Which of the following enzymes is involved in the metabolism (breakdown) of epinephrine?

Correct AnswerverifiedShow Answer

The catabolism and excretion of steroid hormones

Correct AnswerverifiedShow Answer

The phosphorylation of tyrosine residues on a growth factor receptor

Correct AnswerverifiedShow Answer

ACTH has all of the following effects on the adrenal cortex EXCEPT which one?

Correct AnswerverifiedShow Answer

A peptide hormone which is located both in the hypothalamus and in the pancreas is

Correct AnswerverifiedShow Answer

Aldosterone

Correct AnswerverifiedShow Answer

Hormones affect the rates of metabolic pathways by all of the following EXCEPT

Correct AnswerverifiedShow Answer

Which of the following is a major mineralocorticoid in man?

Correct AnswerverifiedC

The insulin? receptor has in common with other growth? Factor receptors such as epidermal growth factor

Correct AnswerverifiedShow Answer

As regards the synthesis of ACTH, which of the following statements, if any, is false?

Correct AnswerverifiedShow Answer

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C

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B

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C

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