Q.74 What is the enzyme involved in the following reaction?
Triglyceride + 3H2O ———–> Glycerol + fatty acids
(A) Glycerol phosphate dehydrogenase
(B) Glycerol kinase
(C) Lipase
(D) Zymase
Lipase is the enzyme that catalyzes the hydrolysis of triglycerides into glycerol and fatty acids. This reaction is a key step in lipid digestion and metabolism, commonly tested in exams like CSIR NET Life Sciences.
Introduction to Triglyceride Hydrolysis
Triglyceride hydrolysis breaks down triglycerides using water to produce glycerol and fatty acids, a vital process in digestion and energy metabolism. The enzyme triglyceride hydrolysis glycerol fatty acids reaction is catalyzed by a specific hydrolase enzyme, essential for CSIR NET Life Sciences preparation. Understanding this helps differentiate it from other glycerol-related pathways.
Correct Answer: Lipase
Lipase performs the hydrolysis of triglycerides into glycerol and three fatty acids in the presence of water. Pancreatic lipase acts in the small intestine, while other types like hormone-sensitive lipase function in adipocytes. This matches the reaction: Triglyceride + 3H₂O → Glycerol + Fatty Acids exactly.
Option Analysis
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(A) Glycerol phosphate dehydrogenase: This FAD-dependent enzyme oxidizes glycerol-3-phosphate to dihydroxyacetone phosphate in the glycerol phosphate shuttle, not hydrolyzing triglycerides.
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(B) Glycerol kinase: This enzyme phosphorylates free glycerol to glycerol-3-phosphate using ATP, involved in glycerol metabolism after hydrolysis, not the breakdown of triglycerides.
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(C) Lipase: Correct, as it specifically hydrolyzes ester bonds in triglycerides to release glycerol and fatty acids.
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(D) Zymase: This yeast enzyme complex ferments glucose to ethanol and CO₂, unrelated to lipid hydrolysis.
Biological Significance
Lipase enables fat digestion, with bile emulsifying triglycerides for access. Defects link to pancreatitis or fat malabsorption. In CSIR NET, this tests biochemistry knowledge of enzyme specificity.
Overview
| Enzyme | Reaction Catalyzed | Relevance to Query |
|---|---|---|
| Lipase | Triglyceride + 3H₂O → Glycerol + 3 Fatty Acids | Direct match |
| Glycerol Phosphate Dehydrogenase | Glycerol-3-P + NAD⁺ → DHAP + NADH | Oxidation, post-hydrolysis |
| Glycerol Kinase | Glycerol + ATP → Glycerol-3-P + ADP | Phosphorylation of glycerol |
| Zymase | Glucose → Ethanol + CO₂ | Fermentation |