Q94 Match the hormones/precursors listed in Column I with their chemical type in Column II and tissue of origin listed in Column III
| Column I | Column II | Column III |
|---|---|---|
| P. Glucagon | (i) Tryptophan derivative | a. Anterior pituitary |
| Q. Pregnenolone | (ii) Peptide | b. Pineal |
| R. FSH | (iii) Steroid | c. Adrenal |
| S. Melatonin | (iv) Glycoprotein | d. Pancreas |
Options:
Match Hormones to Chemical Type and Tissue of Origin for CSIR NET Life Sciences
Glucagon, Pregnenolone, FSH, and Melatonin represent key hormones in endocrine physiology, classified by chemical structure and production sites. This matching question tests foundational knowledge for CSIR NET aspirants in molecular biology and biochemistry. The correct matching is option (A): P-(ii)-(d); Q-(iii)-(c); R-(iv)-(a); S-(i)-(b).
Hormone Classifications
Hormones divide into peptides/proteins, steroids, glycoproteins, and amino acid derivatives based on structure. Peptides like glucagon consist of amino acid chains. Steroids such as pregnenolone derive from cholesterol. Glycoproteins including FSH feature carbohydrate-linked proteins. Tryptophan derivatives like melatonin form from indole pathways.
Detailed Matching
P. Glucagon: Matches (ii) Peptide from Column II and (d) Pancreas from Column III. Glucagon is a 29-amino acid polypeptide hormone secreted by pancreatic alpha cells in islets of Langerhans. It opposes insulin by raising blood glucose via glycogenolysis.
Q. Pregnenolone: Matches (iii) Steroid from Column II and (c) Adrenal from Column III. Pregnenolone, synthesized from cholesterol by CYP11A1 in adrenal cortex mitochondria, serves as a precursor to all steroid hormones. Primary production occurs in adrenal glands, gonads, and brain, with adrenals as the main circulating source.
R. FSH: Matches (iv) Glycoprotein from Column II and (a) Anterior pituitary from Column III. Follicle-stimulating hormone (FSH) is a heterodimeric glycoprotein with alpha/beta subunits, produced by gonadotrophs in the anterior pituitary. It regulates gametogenesis via hypothalamic GnRH stimulation.
S. Melatonin: Matches (i) Tryptophan derivative from Column II and (b) Pineal from Column III. Melatonin derives from tryptophan via serotonin acetylation and methylation in pinealocytes. The pineal gland is the primary source, regulating circadian rhythms.
Option Analysis
(A) P-(ii)-(d); Q-(iii)-(c); R-(iv)-(a); S-(i)-(b): Correct, as detailed above.
(B) P-(ii)-(d); Q-(iv)-(a); R-(iii)-(c); S-(i)-(b): Incorrect. Pregnenolone is steroid (iii), not glycoprotein (iv); FSH is glycoprotein (iv), not steroid (iii); FSH originates in anterior pituitary (a), not adrenal (c).
(C) P-(ii)-(c); Q-(iii)-(b); R-(iv)-(d); S-(i)-(a): Incorrect. Glucagon from pancreas (d), not adrenal (c); Pregnenolone from adrenal (c), not pineal (b); FSH from anterior pituitary (a), not pancreas (d); Melatonin from pineal (b), not anterior pituitary (a).
(D) P-(ii)-(a); Q-(iii)-(d); R-(iv)-(b); S-(i)-(c): Incorrect. Glucagon from pancreas (d), not anterior pituitary (a); Pregnenolone from adrenal (c), not pancreas (d); FSH from anterior pituitary (a), not pineal (b); Melatonin from pineal (b), not adrenal (c).
Hormone chemical classification and tissue origin matching forms a core topic in CSIR NET Life Sciences, covering endocrine system basics for molecular biology and biochemistry exams. This guide solves the matching question on Glucagon (peptide, pancreas), Pregnenolone (steroid, adrenal), FSH (glycoprotein, anterior pituitary), and Melatonin (tryptophan derivative, pineal), with detailed breakdowns for exam success.
Key concepts include peptide hormones’ amino acid chains, steroid precursors from cholesterol, glycoprotein structures with carbs, and amine derivatives from tryptophan. Understanding these aids in grasping hormone synthesis, like CYP11A1 for pregnenolone or pineal AANAT for melatonin. Practice such matchings boosts retention for competitive exams.
