Which of the following hormones derive from amino acids?
estradiol
epinephrine
thyroid hormones
calcitriol
dopamine
Which of the following statements about hyperthyroidism are TRUE?
the blood levels of TSH are higher
hypoglycemia
hyperglycemia
increased thermogenesis
decreased thermogenesis
the blood levels of TSH are lower
List at least three groups of plasma membrane receptors 1) channels 2) - coupled receptor 3) receptors
G protein-coupled receptors
are associated with monomeric G-proteins
are receptors for lipophilic hormones
transmit the signal of epinephrine and glucagon
have an intracellular domain rich in tyrosine
Which of the following statements are NOT TRUE?
glucocorticoids are synthesized in zona glomerulosa of the adrenal gland
adrenal androgens are DHEA and 5-dihydrotestosterone
5-dihydrotestosterone is more potent androgen than testosterone
renin stimulates the conversion of angiotensin 1 into angiotensin 2
17-hydroxylase is the principle regulatory enzyme in streroidogenesis
List at least 3 second messengers in the process of signal transduction 1) cyclic 2) cyclic 3)
Which of the following statements about hypothyroidism are TRUE:
unchanged metabolic rate
CYP 450 side chain cleavage enzyme is the key regulatory enzyme in the synthesis of all the steroid hormones
25-dehydrogenase is the main regulatory enzyme in the synthesis of calcitriol
calcitriol causes a decrease of blood Ca2+ levels
cortisol has a prominent hyperglycemic effect
Which of the following statements are TRUE:
testosterone is less potent androgen than 5-dihydrotestosterone
glucocorticoids are synthesized in zona fasciculata of the adrenal gland
angiotensin ll stimulates the production of aldosterone in zona glomerulosa of the adrenal gland
testosterone is converted into estradiol by 17-ketoreduetase (17β- dehydrogenase)
Based on their chemical composition hormones are:
peptide
autocrine
paracrine
steroid
derivatives of amino acids
phosphodiesterase is inhibited by insulin
epinerphrine and ACTH use cAMP as a second messenger
insulin uses PI3K signaling pathway
guanylyl cyclase activates protein kinase C (PKC)
Which of the following hormones are secreted by anterior pituitary gland:
ACTH
TSH
Angiotensin 2
Antidiuretic hormone (ADH)
Prolactin
Which of the following enzymes are involved in the biosynthesis of corticosteroids the adrenal cortex:
21-hydroxylase
1-α-hydroxylase
3-hydroxysteroid dehydrogenase and Δ5,4-isomerase
cyt. P450 side chain cleavage enzyme (P450scc)
5-α-reductase
Which of the following is NOT TRUE:
Cholesterol side chain cleavage by P450 scc results in production of pregnolone
Cortisol is produced in zone fasciculata
Aldosterone is produced in zona reticularis
Estrogens biosynthesis requires aromatase activity
Thyroid hormones are made from tyrosine
The synthesis of thyroid hormones is stimulated by TSH
T4 is more active than T3
Iodine transport in the thyroid follicle is energy dependent
What happens to protein kinase A (PKA) following the binding of cAMP
the regulatory subunits of PKA dissociate, therby activating the catalytic subunits
PKA catalytic subunits bind to the regulatory subunits
the regulatory subunits dissociate from the catalytic subunits causing inactivation of the enzyme
Thyroid hormones T3 and T4 derive from threonine
TSH and ACTH bind to cell surface G-proteins coupled receptors (GPCR)
Insulin is a polypeptide hormone that consists of A and B chain
ACTH and endorphins derive from a large precursor called POMC
Which of the following about testosterone is NOT TRUE:
Testosterone is a lipophilic hormone
Testosterone has cell surface receptors with tyrosine kinase activity
Testosterone is formed from dihydrotestosterone (DHT) in peripheral tissues
DHT is formed from testosterone in reaction catalyzed by 5-α-reductase
Ras protein is a key regulator in cell proliferation and its activity is enhanced by activated tyrosine kinase. Its action include:
Formation of c. AMP
Formation of c. GMP
Initiation of a cascade in which several kinases are activated sequentially by phosphorylation
Ras is a heterotrimeiric G-protein
Which of the following is TRUE:
Adrenaline and Glucagon inhibit glycogen phosphorylase
Cortisol stimulates gluconeogenesis and lipolysis
Aldosterone increases blood pressure
The major driving force for aldosterone biosynthesis is angiotensin II
The active form of vit. D3 is calcitriol
Vit. D3 is synthesized in the skin from 7- dehydrocholesterol under UV-light
Calcitriol inhibits the intestinal absorption of Ca2+ and phosphate
Calcitriol plays important role in bone mineralization
Which of the following hormones are secreted by the anterior lobe of the pituitary gland?
FSH
Renin
ADH
Oxytocin
TRH
Insulin:
can signal through MAPK pathway
triggers cAMP- dependent pathway
can signal through P13K-pathway
has dimeric receptors with intrinsic tyrosine kinase activity
Which are the mediators of the signal of lipophilic hormones?
Ca2+
Inositol-1,4,5-trisphospahte
hormone-receptor complex
DAG
Which of the following statements about thyroid hormones are TRUE?
T4 can be a product both of the thyroid and the peripheral tissues
T3 can be a product both of the thyroid and the peripheral tissues
T3 is more active than T4
Thyroid receptors are cytosolic intracellular
Which of the following statements about aldosterone are TRUE?
its synthesis is stimulated by ACTH
its synthesis is stimulated by angiotensin ll
it decreases K+ and H+ excretion
it increases Na+ and water reabsotption
its receptors are cytosolic intracellular
it is synthesized in zona fasciculata of the adrenal cortex
Which of the following hormones are stored and released by the posterior lobe of the pituitary gland?
ADH (vasopressin)
divergention of the signal means that different signal pathways have the same common targets or intermediate components
crosstalk of the signals means that one signal molecule can transmit signals from different extracellular messengers (signal molecules)
acetylcholine transmit its signals through receptors associated with ion channels
acetylcholine transmit its signals through receptors associated with intrinsic serine-threonine kinase activity
Which of the following hormones have cell-surface receptors?
epinerphrine
testosterone
insulin
retinols
Based on their mechanism of action the hormones are:
Autocrine
Peptide
Steroid
Paracrine
Endocrine
Which of the following hormones bind to intracellular receptors:
Thyroid hormones
Glucagon
Steroid hormones
Which of the following hormones have cell surface receptors:
Testosterone
Insulin
T4 and T3
Growth hormone
Which of the following statements about insulin receptor is TRUE
it has intrinsic tyrosine kinase activity
it is located in the nucleus
it is a dimer composed of two α and two β subunits
it is coupled with G-protein
C.AMP is a key second messenger in the transduction of hormone signals
Adenylyl cyclase is activated by insulin
Adenylyl cyclase catalyzes the synthesis of AMP from ATP
Hormones like adrenaline, glucagon and ACTH use cGMP as second messenger
Insulin receptor has serine/threonine kinase activity
Binding of insulin to its membrane receptor stimulates the tyrosine kinase activity of the β-subunits
Insulin is a lipophilic hormone
Cortisol is a lipophilic hormone
Cholesterol side chain cleavage by P450 scc results in production pregnenolone
Cortisol is produced in zona glomerulosa
Testosterone biosynthesis requires aromatase activity
Which of the following are second messengers:
C. AMP
Inositol- 1,4,5- triphosphate
Triacylglycerol
Diacylglycerol
Ca2+ and calmodulin
Which of the following hormones stimulate adenylyl cyclase:
Which of the following hormones are cholesterol derivatives:
Calcitriol
Cortisol
T3 and T4
Estradiol
