Question 56:
Which of the following statements are correct?
Choose the correct answer from the options given below:
The correct answer is (C) (A), (B), (C) and (D).
All statements accurately describe lipid biology: lipids as signaling cofactors, prostaglandins from arachidonate via COX pathway, steroid hormones from sterols like cholesterol, and vitamins D/A/E as fat-soluble.
Option Breakdown
(A) (A), (B) and (D) only
Incorrect; misses (C) steroid hormone derivation from sterols, a fundamental biochemistry fact.
(B) (A), (B) and (C) only
Wrong; excludes (D) fat-soluble vitamins D/A/E, confirmed in prior Vitamin D3 query.
(C) (A), (B), (C) and (D)
Correct; all align with lipid metabolism—eicosanoids from arachidonic acid, steroids from cholesterol backbone, vitamins absorbed via micelles.
(D) (B), (C) and (D) only
No; omits (A) lipids’ roles (e.g., phosphatidylinositol as second messengers).
Introduction to Lipids Cofactors Prostaglandins Steroid Hormones
Lipids cofactors prostaglandins steroid hormones encompass diverse roles from signaling (A), arachidonate-derived eicosanoids (B), cholesterol-based endocrines (C), to fat-soluble vitamin absorption (D). All correct for GATE Life Sciences lipid metabolism.
Statement Verification
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(A) Lipids like dolichol (glycosylation cofactor) or IP3 (signal) prove multifunctional.
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(B) Prostaglandins arise via PLA2 release of arachidonic acid, COX conversion to PGH2, then tissue-specific synthases.
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(C) Steroid hormones (cortisol, estrogen) derive from squalene→cholesterol sterol precursor.
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(D) Vitamins D3 (cholecalciferol), A (retinol), E (tocopherol) dissolve in lipids for intestinal uptake.
Statements Correctness Table
| Statement | Key Fact [Source] | Correct? |
|---|---|---|
| (A) Lipids as cofactors/signals | IP3, dolichol roles | Yes |
| (B) Prostaglandins from arachidonate | COX pathway | Yes |
| (C) Steroids from sterols | Cholesterol backbone | Yes |
| (D) Vitamins D/A/E fat-soluble | Micelle absorption | Yes |
Option C includes all for lipids cofactors prostaglandins steroid hormones.
Exam Strategy for Life Sciences
Builds on prior queries (D3=cholecalciferol, trans fats, Warfarin-vitamin K); memorize lipid classifications for biochemistry PYQs.
