Peroksisomi

undergraduate thesis

• Title (english): Peroxisomes
• Author: Magdalena Mrkonja
• Mentor: Maja Matulić (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2024-09-17, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Peroksisomi su kuglasti organeli prisutni u gotovo svim eukariotskim stanicama. Obavijeni su jednoslojnom membranom, nemaju vlastiti genetički materijal i osnovna im funkcija je oksidacija različitih supstrata. Glavne metaboličke uloge peroksisoma su β-oksidacija, detoksikacija reaktivnih kisikovih vrsta te glioksilatni ciklus i fotorespiracija u biljnim stanicama. Nastaju diobom postojećih peroksisoma, mehanizmom nalik mitohondrijskom ili de novo pupanjem vezikula s endoplazmatskog retikuluma. Za nastanak peroksisoma važni su proteini peroksini. Proteini peroksisoma sintetiziraju se na slobodnim ribosomima u stanici i unose se posttranslacijski kao smotani ili oligomerni proteini u matriks peroksisoma kroz privremenu poru koja nastaje na njihovoj membrani. Peroksini Pex5 i Pex7 služe kao topljivi receptori za unos proteina matriksa, a Pex19 služi kao receptor za ugradnju proteina membrane peroksisoma. Broj peroksisoma u stanici je reguliran i postoje mehanizmi koji kontroliraju nasljeđivanje peroksisoma. Peroksisomi se većinom degradiraju procesom peksofagije koja je regulirana ubikvitinacijom. Bolesti vezane u peroksisome mogu biti uzrokovane nedostatkom pojedinog enzima, primjerice X-vezana adrenoleukodistrofija ili nedostatkom funkcionalnih peroksisoma, primjerice Zellwegerov sindrom.

Abstract (english)

Peroxisomes are spherical organels present in almost all eukaryotic cells. They are enclosed in a single membrane, they do not have their own genetic material and their primary function is oxidation of different substrates. Key metabolic roles of peroxisomes are β-oxidation, detoxification of reactive oxygen species, and glyoxylate cycle and photorespiration in plant cells. Peroxisomes arise by division of existing peroxisomes by mechanism like that of mitochondria or by de novo biogenesis by budding of vesicles from endoplasmic reticulum. Peroxins are proteins important for peroxisomal biogenesis. Peroxisomal proteins are synthesized on free ribosomes in cells and are posttranslationally imported in folded or oligomeric shape through transient pore on peroxisomal membrane. Peroxins Pex5 and Pex7 are soluble receptors for matrix protein import and Pex19 is a receptor for import of peroxisomal membrane proteins. Number of peroxisomes in cells is regulated and there are mechanisms that direct inheritance of peroxisomes during cell division. Peroxisomes are mostly degraded by pexophagy which is mostly regulated by ubiquitination. Peroxisome disorders can be caused by a single enzyme deficiency, such as in X-linked adrenoleukodystrophy, or by absence of functional peroxisomes, such as in Zellweger syndrome.

• Keywords: peroksini; nastanak peroksisoma; peksofagija; katalaza; β-oksidacija
• Keywords (english): peroxines; peroxisome biogenesis; pexophagy; catalase; β-oxidation
• Language: croatian
• URN:NBN: urn:nbn:hr:217:815716
• Study programme: Title: Molecular biology-University undergraduate programme; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-09-30 11:01:43