In uncontrolled diabetes mellitus, a patient develops a fruity odor on the breath. The ketone body responsible for this odor is generated from acetoacetate by which process?

• A Thiokinase-mediated activation
• B Spontaneous decarboxylation ✓
• C Reduction by mitochondrial dehydrogenase using NADH
• D Transamination to a ketoacid

Explanation

Acetone arises when acetoacetate undergoes spontaneous, nonenzymatic decarboxylation; it is volatile, appears on the breath, and is excreted in expired air rather than used as fuel. Reduction by NADH converts acetoacetate to beta-hydroxybutyrate instead, killing option C. Thiokinase activates long-chain fatty acids for beta-oxidation, not ketones, and transamination is irrelevant to ketone body chemistry.

Reference: Lehninger Principles of Biochemistry, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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