Q74.Match List I with List II
| LIST I | LIST II |
|---|---|
| A. Fatty acids | I. Tetracycline, Aflatoxin B₁ |
| B. Glycerolipids | II. Oleate, Stearoyl-CoA |
| C. Saccharolipids | III. Triacylglycerols |
| D. Polyketides | IV. Lipopolysaccharide |
Choose the correct answer from the options given below:
(1) A-III, B-II, C-I, D-IV
(2) A-II, B-III, C-I, D-IV
(3) A-II, B-III, C-IV, D-I
(4) A-III, B-II, C-IV, D-I
Fatty acids, glycerolipids, saccharolipids, and polyketides are key lipid categories tested in exams like CSIR NET Life Sciences. The correct matching for this question is option (3): A-II, B-III, C-IV, D-I.
List I-II Breakdown
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A. Fatty acids → II. Oleate, Stearoyl-CoA: Fatty acids are carboxylic acids with long hydrocarbon chains; oleate (C18:1 unsaturated) and stearoyl-CoA (activated stearic acid, C18:0) are classic examples.
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B. Glycerolipids → III. Triacylglycerols: These have glycerol esterified with three fatty acids, like triacylglycerols (TAGs, storage lipids).
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C. Saccharolipids → IV. Lipopolysaccharide: Saccharolipids feature fatty acids directly linked to a sugar backbone (no glycerol); LPS (lipid A from Gram-negative bacteria) exemplifies this.
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D. Polyketides → I. Tetracycline, Aflatoxin B₁: These are secondary metabolites from polyketide synthases; tetracycline (antibiotic) and aflatoxin B₁ (mycotoxin) fit perfectly.
Option Analysis
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(1) A-III, B-II, C-I, D-IV: Wrong; fatty acids aren’t triacylglycerols (needs glycerol), and saccharolipids aren’t polyketides.
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(2) A-II, B-III, C-I, D-IV: Wrong; saccharolipids (C) mismatched to polyketides (I), LPS (IV) ignored.
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(3) A-II, B-III, C-IV, D-I: Correct; aligns with LIPID MAPS classification (fatty acids simple chains, glycerolipids glycerol-based, saccharolipids sugar-linked, polyketides PKS-derived).
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(4) A-III, B-II, C-IV, D-I: Wrong; glycerolipids (B) not fatty acids/esters (II).
Mastering Match List I with List II questions on lipid categories like fatty acids, glycerolipids, saccharolipids, and polyketides is essential for CSIR NET, GATE Life Sciences, and NEET PG exams. This guide solves Q74 step-by-step, explains fatty acids oleate stearoyl-CoA, glycerolipids triacylglycerols, saccharolipids lipopolysaccharide, and polyketides tetracycline aflatoxin, analyzes all options, and shares prep strategies.
Lipid Categories Defined
Lipids follow LIPID MAPS classification for precise matching.
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Fatty acids: Straight-chain carboxylic acids (e.g., oleate: C18:1 Δ9; stearoyl-CoA: activated form).
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Glycerolipids: Glycerol with 1-3 fatty acyl chains (e.g., triacylglycerols/TAGs for energy storage).
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Saccharolipids: Fatty acids bound directly to sugar (e.g., LPS lipid A: bacterial endotoxin, glucosamine core).
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Polyketides: Biosynthesized by polyketide synthases (e.g., tetracycline: antibiotic; aflatoxin B₁: toxin).
Correct Option: Why (3)?
Option (3) A-II, B-III, C-IV, D-I perfectly matches definitions—no glycerol in saccharolipids (rules out III), polyketides distinct from lipids but categorized here.
Why Other Options Fail
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Option (1): Mismatches A to glycerolipids (III; needs glycerol) and C to polyketides (I).
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Option (2): C to polyketides (I; ignores LPS sugar link).
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Option (4): B to fatty acids/esters (II; glycerolipids require glycerol backbone).
Exam Tips for Lipid Matching
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Memorize LIPID MAPS: Fatty acids (simple), glycerolipids (glycerol), saccharo (sugar), prenols/polyketides (special).
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Spot tricks: LPS is saccharolipid (not phospholipid), tetracycline polyketide (not fatty acid).
