MCAT® ExamBiological and Biochemical Foundations of Living SystemsEasy
A patient is diagnosed with a genetic disorder characterized by the inability to properly break down long-chain fatty acids, leading to their accumulation in various tissues. This condition is most likely due to a defect in which cellular organelle?
- AEndoplasmic Reticulum
- BMitochondria
- CPeroxisomes
- DLysosomes
Show answer & explanationAnswer & explanation
Correct answer: C. Peroxisomes
Peroxisomes are organelles responsible for breaking down very long-chain fatty acids through beta-oxidation. A defect in peroxisomal function would lead to the accumulation of these fatty acids.
Why the other options are wrong
- A. The Endoplasmic Reticulum is involved in protein synthesis and lipid metabolism, but not the primary site for long-chain fatty acid breakdown.
- B. Mitochondria are involved in ATP production and the beta-oxidation of shorter fatty acids, but peroxisomes handle very long-chain fatty acids.
- D. Lysosomes are primarily involved in the degradation of cellular waste and macromolecules, but not specifically very long-chain fatty acids.
Peroxisome Function
Peroxisomes are small, membrane-bound organelles containing enzymes that participate in various metabolic reactions, including the breakdown of very long-chain fatty acids, branched-chain fatty acids, and amino acids, as well as detoxification of harmful substances.
- Breakdown of very long-chain fatty acids via beta-oxidation.
- Detoxification of hydrogen peroxide (H2O2) using catalase.
- Involved in synthesis of plasmalogens (ether lipids).
- Play a role in cholesterol and bile acid synthesis.
Memory trick: Peroxisomes: Powerhouses for Perilous Fats.