Viral envelopes: Which lipid class predominates in the membranes that form the viral envelope derived from host cells?
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Aphospholipids
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Bglycolipids
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Cneutral fat
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Dall of these
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Eceramides only
Answer
Correct Answer: phospholipids
Explanation
Introduction / Context:Enveloped viruses bud through host membranes, acquiring a lipid bilayer. Knowing its composition helps explain sensitivity to detergents, desiccation, and disinfectants.
Given Data / Assumptions:
- Viral envelopes are derived from host plasma membrane or internal membranes.
- Typical eukaryotic membranes are composed mainly of phospholipids and cholesterol, with smaller fractions of glycolipids.
- Neutral fats (triacylglycerols) are storage lipids, not main bilayer components.
Concept / Approach:The bilayer’s structural backbone is phospholipids, which form amphipathic sheets. Cholesterol modulates fluidity but is not listed among options. Therefore, the predominant lipid class is phospholipids.
Step-by-Step Solution: Identify the source of the envelope: host membrane. Recall membrane composition: mostly phospholipids with cholesterol. Exclude storage and minor lipid classes. Choose “phospholipids”.
Verification / Alternative check:Basic cell biology consistently places phospholipids as the principal bilayer constituents across cell and viral envelopes.
Why Other Options Are Wrong:
- Glycolipids: Present but minor compared with phospholipids.
- Neutral fat: Not a bilayer structural lipid.
- All of these: Overstates contributions of non-structural lipids.
- Ceramides only: Too narrow; sphingolipids are not exclusive.
Common Pitfalls:Equating storage lipids with membrane structure, or assuming all lipid classes contribute equally.
Final Answer:phospholipids.