Question

Which of the following respiratory substrates requires the highest number of oxygen molecules for its complete oxidation?

• A. Tripalmitin
• B. Triolein
• C. Tartaric acid
• D. Oleic acid

Answer 1

The correct option is B Triolein

Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils.
Triolein is a symmetrical triglyceride derived from glycerol and three units of the unsaturated fatty acid oleic acid.
Tripalmitin is a saturated triglyceride derived from the fatty acid palmitic acid.
Tartaric acid is a white crystalline organic acid.
The required number of oxygen molecule for oxidation of unsaturated glyceride is always more than the number of oxygen required for complete oxidation of saturated glyceride or acids.
Therefore, triolein which has three units of unsaturated oleic acids, needs more oxygen than oleic acid, tripalmitin, which is a saturated fatty acid and the simple acid, tartaric acid.