Quick Facts
A peroxisome is a microbody present in all animal cells except erythrocytes and many plant cells, containing over 50 enzymes that participate in a variety of oxidative processes, including reactions involving hydrogen peroxide, purine metabolism, cellular lipid metabolism, and gluconeogenesis (Dorland, 2011).
Structure and/or Key Feature(s)
Peroxisomes are small, spherical membrane bound sacs (0.5-1.2 μm in diameter) derived from smooth endoplasmic reticulum containing enzymes involved in oxidative digestion (Ross and Pawlina, 2006).
Function
Peroxisomes are involved in the oxidation of specific organic substrates including long chain fatty acids. They can convert hydrogen peroxide that is formed during the various metabolic activities to water due to them containing the enzyme catalase. This catalase activity (particularly in cells in the liver and kidney) also facilitates them degrading toxic molecules including drugs (Ross and Pawlina, 2006).
List of Clinical Correlates
Adrenoleukodystrophy (ALD) is due to a membrane protein being absent in peroxisomes. This protein transports an enzyme into the peroxisome that regulates the breakdown of very long-chain fatty acids ingested in a normal diet. The fatty acids accumulate in the cell and in the case of nerve cells (neurons) eventually cause disintegration of their myelin covering. This build-up of fatty acid also affects the function of cells in the adrenal gland (Ross and Pawlina, 2006; McKinley, O'Loughlin and Pennefather-O'Brien, 2016).
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
McKinley, M. P., O'Loughlin, V. D. and Pennefather-O'Brien, E. E. (2016) Human Anatomy. 5th edn.: McGraw-Hill Education.
Ross, M. H. and Pawlina, W. (2006) Histology: A text and atlas. Lippincott Williams & Wilkins.
