U01.01.023 Peroxisome

Peroxisomes are membrane-enclosed organelles found in most eukaryotic cells. They play a crucial role in various metabolic processes, particularly the breakdown of fatty acids. Here’s a breakdown of their key functions and associated diseases:

Functions of Peroxisomes:

Function	Description
β-oxidation of very-long-chain fatty acids (VLCFA)**	Peroxisomes specialize in breaking down VLCFAs, a process essential for energy production and maintaining cellular balance.
α-oxidation of branched-chain fatty acids	Peroxisomes also handle the breakdown of specific branched-chain fatty acids.
Catabolism of amino acids and ethanol	Certain amino acids and ethanol can be broken down within peroxisomes.
Synthesis NOT (mistake in original text)	Peroxisomes do not synthesize cholesterol, bile acids, or plasmalogens. These processes occur in other organelles like the endoplasmic reticulum and liver.

Diseases Associated with Peroxisome Dysfunction:

Zellweger Syndrome:
- This autosomal recessive disorder results from mutations in genes (PEX genes) critical for peroxisome biogenesis (formation).
- Symptoms include hypotonia (muscle weakness), seizures, and enlarged liver (hepatomegaly), and often lead to early death.
Refsum Disease:
- An autosomal recessive disorder affecting α-oxidation. A specific fatty acid (phytanic acid) accumulates due to a mutation that prevents its conversion to pristanic acid.
- Symptoms include scaly skin, ataxia (incoordination), cataracts, night blindness, shortened fourth toe, and bone abnormalities. Treatment involves dietary restrictions and plasmapheresis (removal of excess phytanic acid from blood).
Adrenoleukodystrophy (ALD):
- This X-linked recessive disorder arises from a mutation in the ABCD1 gene, leading to a malfunction in β-oxidation.
- VLCFAs accumulate in the adrenal glands, the white matter of the brain, and testes.
- ALD is a progressive disease with symptoms ranging from adrenal insufficiency to coma and death if untreated.

Understanding Peroxisomes:

Peroxisomes are essential organelles for proper metabolism. Disruptions in their function can lead to various clinical conditions. By studying these diseases, we gain valuable insights into the critical roles peroxisomes play in maintaining cellular health.

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U01.01.023 Peroxisome

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