This set of Molecular Endocrinology Multiple Choice Questions & Answers (MCQs) focuses on “Pituitary Tropic Hormones”.
1. Which among the following are the milk proteins produced after parturition with the help of tropin hormones?
a) Lactalbumin and casein
b) Insulin
c) Oxytocin
d) Lactoferrin
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Explanation: After parturition, the synthesis of milk proteins such as lactalbumin and casein takes place, and such an effect is called lactogenic action. The tropin hormone prolactin secreted from anterior pituitary gland carries out this role.
2. Which female hormone increases the number of prolactin receptors on the cell membrane of mammary glands?
a) Progesterone
b) Estrogen
c) Oxytocin
d) Vasopressin
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Explanation: On the mammary cell membrane, the female hormone estrogen increases the number of prolactin receptors. Along with this, thyroid hormones and glucocorticoids also increase the number of prolactin receptors. Whereas the opposite reaction is shown by progesterone.
3. Which hormone is secreted by the basophil cells of anterior pituitary?
a) Vasopressin
b) Oxytocin
c) Thyrotropic Hormone or Thyroid Stimulating Hormone (TSH)
d) Insulin
View Answer
Explanation: Thyrotropic Thyroid Stimulating Hormone (TSH) is the hormone produced by the anterior pituitary basophil cells and it is a glycoprotein in nature. Its molecular mass is about 30,000 and it has ‘a’ and ‘b’ subunits.
4. The biological specificity of thyrotropin hormone lies in its alpha subunit.
a) True
b) False
View Answer
Explanation: The biological specificity of the hormone thyrotropin lies in its beta subunit. The alpha subunits of Thyroid Stimulating Hormone (TSH), Luteinizing Hormone (LH), Human Chorionic Gonadotropin (HCG) and Follicle Stimulating Hormone (FSH) hormones are almost similar.
5. Tropin or tropical hormones are the ones that regulates the functions of other endocrine glands.
a) True
b) False
View Answer
Explanation: A tropin or tropical hormone is the one that affects the functions of other endocrine glands. These hormones are transferred to other target glands by blood. Their primarily involved in stress and reproduction.
6. Which pituitary tropic hormone carries out iodine uptake and organification?
a) FSH
b) TSH
c) LH
d) GH
View Answer
Explanation: Thyroid Stimulating Hormone (TSH) facilitates the synthesis of thyroid hormones at all stages such as iodine uptake, organification and coupling. It also increases the release of thyroid hormones which are stored.
7. Which among the actions of TSH hormone does not involve cAMP second messenger?
a) Phospholipid synthesis
b) Glycolysis
c) TCA cycle
d) Mitochondrial synthesis
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Explanation: TSH has a variety of functions, including activation of glycolysis, TCA cycle, HMP and phospholipid synthesis. However, phospholipid synthesis enhancement and HMP do not require c-AMP second messenger.
8. Which are the two forms of Adrenocorticotropic Hormone (ACTH) that are isolated till now?
a) ACTH 1 and ACTH 2
b) Corticotropin ‘a’ and Corticotropin ‘b’
c) Alpha ACTH and beta ACTH
d) Alpha corticotropin and beta corticotropin
View Answer
Explanation: Adrenocorticotropic Hormone (ACTH) or Corticotropin is a single polypeptide hormone with 39 amino acids. Two forms of this hormone, alpha corticotropin and beta corticotropin, have been isolated till now.
9. Which is the glycoprotein precursor molecule synthesized from corticotropin hormone?
a) Pro-opiomelanocortin
b) Leptin
c) Collagen
d) Corticosteroids
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Explanation: The corticotropin precursor molecule is synthesized as a glycoprotein named POMC (Pro-opiomelanocortin peptide). In order to give different peptides, various proteolytic enzymes hydrolyze POMC.
10. Which two molecules are produced after the breakdown of the corticotropin precursor Pro-opiomelanocortin?
a) ACTH and alpha lipotropin
b) ACTH and beta lipotropin
c) cAMP and beta lipotropin
d) cAMP and alpha lipotropin
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Explanation: POMC breaks down into beta-lipotropin (LPH) and Adrenocorticotropic Hormone (ACTH) with the action of proteolytic enzymes. Beta-LPH is further separated into gamma-LPH and endorphins, respectively.
11. Which hormone stimulates the synthesis and release of corticosteroids from adrenal gland?
a) TSH
b) Oxytocin
c) ACTH
d) Vasopressin
View Answer
Explanation: Corticotropin exerts its main actions on the adrenal cortex and extra adrenal tissue. ACTH increases the adrenal cortex’s synthesis of corticosteroids and also stimulates their release from the gland.
12. Which cells contain the ACTH receptors that increases the synthesis of cAMP second messengers?
a) Beta cells
b) Alpha cells
c) Adrenal cells
d) Fasciculata cells
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Explanation: ACTH has been shown to have specific receptors on fasciculata cells that increase the level of c-AMP in the cell. This activation is reliant on calcium. DNA materials are produced as a result of this and then RNA is transcribed.
13. How do corticotropin hormone carry out the hydroxylation of cholesterol?
a) By binding cholesterol to mitochondrial cytochrome P450
b) By binding cholesterol to cytosolic cytochrome c
c) By binding cholesterol to mitochondrial cytochrome c
d) By binding cholesterol to NADH
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Explanation: Corticotropin facilitates the binding of the cholesterol necessary for hydroxylating cholesterol to mitochondrial cytochrome P450. The rate-limiting enzyme for the conversion of cholesterol to pregnenolone is also activated by this hormone.
14. Which among the following is an example of gonadotropin hormone released from pituitary gland?
a) TSH
b) FSH
c) Testosterone
d) Progesterone
View Answer
Explanation: Tropic hormones affect the role of the testes and ovaries and their maturation. Such tropic hormones are known as gonadotropins which include Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH).
15. Which tropic hormone enhances the release of estrogen hormone in females?
a) Oxytocin
b) Vasopressin
c) FSH
d) TSH
View Answer
Explanation: The Follicle Stimulating Hormone (FSH) gonadotropic hormone stimulates follicular production and repairs the LH action of the Graafian follicle. It also enhances the release of LH (Luteinizing hormone) induced estrogen.
Sanfoundry Global Education & Learning Series – Molecular Endocrinology.
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