Peroxisome in animal cell|
Life sciences, HAN university of applied science, Nijmegen, Netherlands| |
Peroxisome in animal cell
Author: Mohsen Ghanbari
Peroxisomes have an essential function in cell metabolism.  They are small, membrane bounded organelles that have at least fifty different enzymes for several metabolic reactions.  Their appearance is like lysosomes; however, their main function is oxidation reactions especially oxidation of hydrogen peroxide and producing oxygen and water. There are diseases related and caused by this organelle that can be classified in three groups.  First group is a disorder duo to overall dysfunction of peroxisomes, like zellweger syndrome, second group duo to dysfunction of only some peroxisomal functions, Example for disorder of this group is rhizomelic chondrodysplasia punctata and third group because of dysfunction of a single peroxisomal function, Example of this group is acatalasemia. In this review I will report the function and dysfunction of peroxisomes, their appearance, related diseases future plans as well as techniques for isolation and visualization of them. From the literature it is known that beta oxidation of long chain and very long chain fatty acids is a lake in group one disorders like infantile refsum's. On the other hand in x-linked adrenoleukodystrophy the lake of beta oxidation of very long chain fatty acids can be seen. Introduction
Peroxisome is a core shape organelle in both animal and plant cells bounded by a single membrane. The main function is oxidation in other word it contain enzymes that transfer hydrogen from various substrate to oxygen making hydrogen peroxide as a by-product. The reactions inside peroxisomes have different functions such as: breaking down the fatty acids to smaller molecules for further reactions in mitochondria, detoxifying the harmful compounds in cells especially liver cells. Peroxisomes grow larger and after reaching a certain size they will split in two. The problems with dysfunctioning of peroxisomes are mostly a group of genetically heterogeneous metabolic diseases.  There are enzymatic abnormalities that can be single or multiple. One of the features of most peroxisomal dysfunctions is neurological disorders. There are medical care and treatments which depends on several items such as level of disorder, age of patient, risks and benefits of treatment etc.
Appearance and location
Proxisomes are small vesicles found around the cell and have a single membrane of lipid bilayer that contains digestive enzymes in order to break down the toxic materials in cell.  They also have a dense crystalline core in the middle that is the place for oxidative enzymes.  Fig 1. Peroxisome and its crystaline core. 
They sometimes appear spherical in transmission electron micrographs and have a varying size of 0.1 fm to 1.0 fm. 
Peroxisomes take the required nutrients for cells.  They digest fatty acids, amino acids and do cholesterol synthesis and many of them exist in liver cells to take part in ethanol digestion. The peroxisomal enzymes affect complex molecules and break theme down into smaller molecules; one of the most common side products of digestion is Hydrogen peroxide that is broken down to water and oxygen. Oxygen can be used for next digestion reaction. For example white blood cells produce hydrogen peroxide in order to fight bacteria.  This compound will break down by peroxisomal enzymes to oxygen and water. These enzymes (peroxisomal enzymes) are usually created by lysosomes and finally inserted into the peroxisome.  The main function of peroxisome is to help cell remove the toxic material such as hydrogen peroxide; so they contain oxidation enzymes like D-amino acid oxidase, ureate oxidase and catalase.  Peroxisomes are a major place of oxygen production thanks to hydrogen peroxide oxidation activity. Isolation...