Peroxisomes

In 1965, C. de Duve discovered peroxisomes in liver cells. J. A . Rhodin had previously described them as “microbodies.” They are small, spherical organelles with a diameter of about 0.2–1.5 μmm, which are ubiquitous in cells. Peroxisomes have a single membrane as their outer border. Their finely granular or homogeneous content is electron-dense. Occasionally, peroxisomes enclose paracrystalline materials. Peroxisomes are respiratory organelles. They contain various oxidases, catalase and the enzymes for the β-oxidation of fatty acids. Peroxisomes owe their name to their peroxidative enzyme content.  They play an important role in the detoxification of cells. Example: the enzyme catalase will split hydrogen peroxide, a lethal cell poison. Genetic diseases that are based on peroxisomal defects include Zellweger syndrome ,  Ref sum syndrome and adrenoleukodystrophy . Section from an epithelial cell (human liver) with two peroxisomes of different sizes.

1 Section through a mitochondrion

2 Smooth endoplasmic reticulum (sER) membranes

3 Areas with cellular glycogen (glycogen removed)

Section through a mouse epithelial cell from a proximal kidney tubule with several peroxisomes, which are rich in catalase 1 .

1 Peroxisomes

2 Nucleus (partial section)

3 Mitochondria (crista-type)

4 Granular ER (rER) membranes

5 Peritubular connective tissue space

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgart · New York .