Q.75 Match List I with List II :
List I
- (A) Stearic acid
- (B) Palmitic acid
- (C) Myristic acid
- (D) Lauric acid
List II
- (I) n-octadecanoic acid
- (II) n-dodecanoic acid
- (III) n-tetradecanoic acid
- (IV) n-hexadecanoic acid
Choose the correct answer from the options given below:
- (1) (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
- (2) (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- (3) (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
- (4) (A)-(I), (B)-(IV), (C)-(III), (D)-(II)
The correct answer is option (4): (A)-(I), (B)-(IV), (C)-(III), (D)-(II).
This matching question tests saturated fatty acid nomenclature by carbon chain length, fundamental for GATE Life Sciences lipid biochemistry.
Matching Explanations
(A) Stearic acid → (I) n-octadecanoic acid
Stearic acid = C18:0 (18 carbons), systematic name n-octadecanoic acid (octadeca = 18).
(B) Palmitic acid → (IV) n-hexadecanoic acid
Palmitic acid = C16:0 (16 carbons), systematic name n-hexadecanoic acid (hexadeca = 16).
(C) Myristic acid → (III) n-tetradecanoic acid
Myristic acid = C14:0 (14 carbons), systematic name n-tetradecanoic acid (tetradeca = 14).
(D) Lauric acid → (II) n-dodecanoic acid
Lauric acid = C12:0 (12 carbons), systematic name n-dodecanoic acid (dodeca = 12).
Carbon count mnemonic: Lau(12)-Myr(14)-Palm(16)-Stear(18)
Option Analysis
Option A-I B-IV C-III D-II Correct? (1) ✗ ✗ ✓ ✗ No (2) ✓ ✗ ✓ ✗ No (3) ✗ ✗ ✗ ✗ No (4) ✓ ✓ ✓ ✓ Yes Only option (4) matches systematic IUPAC names to common fatty acid names by carbon atoms.
Saturated Fatty Acid Nomenclature
Stearic palmitic myristic lauric acid systematic names matching tests lipid chemistry carbon chain length knowledge essential for GATE Life Sciences. Master C12-C18 saturated fatty acids: Lau12-Myr14-Palm16-Stear18 pattern.
Stearic Acid: C18 n-Octadecanoic Acid
Stearic acid (C17H35COOH) from animal fats, highest melting point (69°C) among these.
Palmitic Acid: C16 n-Hexadecanoic Acid
Palmitic acid (C15H31COOH), most common saturated fatty acid in palm oil, cell membranes.
Myristic Acid: C14 n-Tetradecanoic Acid
Myristic acid (C13H27COOH) from nutmeg, dairy; myristoylation modifies proteins.
Lauric Acid: C12 n-Dodecanoic Acid
Lauric acid (C11H23COOH), coconut oil; medium-chain for rapid metabolism.
Quick Exam Reference Table
Common Name Carbons IUPAC Name Formula Lauric 12 n-Dodecanoic C11H23COOH Myristic 14 n-Tetradecanoic C13H27COOH Palmitic 16 n-Hexadecanoic C15H31COOH Stearic 18 n-Octadecanoic C17H35COOH Memory trick: Little Mice Prefer Steaks (12-14-16-18)**