Name: cell compartments in eukaryotes
Uploaded: 2020-11-23T11:47:33.000Z
Duration: 1 min 46 s
Channel: JoVE

- [Narratore] Le cellule
eucariote contengono

numerosi scomparti interni,

organuli circondati da membrane,

che permettono funzioni molto specifiche

all'interno di microambienti,

protetti sia dall'interno citoplasmatico

che dai dintorni extracellulari.

Ad esempio, il nucleo richiede

condizioni controllate per
una regolazione precisa

dei geni all'interno.

Quindi, è circondato
da una doppia membrana,

la membrana nucleare,

con pori per controllare
quali molecole possono entrare

e uscire, come le MRNA.

Inoltre, alcune proteine
richiedono un ambiente ossidante

e devono essere isolate dal citosol

che è riducente.

Quindi, i ribosomi
producono queste proteine

all'interno del reticolo endoplasmatico

dove possono anche subire
modifiche critiche.

Movimenti successivi si verificano

entro piccoli microcosmi
chimici detti vescicole,

mentre si dirigono alla
destinazione finale.

Altri organuli, come i perossisomi,

forniscono protezione dai
loro prodotti derivati dannosi

come il perossido di idrogeno,

sequestrando enzimi che
convertono composti tossici

in molecole innocue come l'acqua.

In modo simile, i lisosomi
segregano gli enzimi,

ma per un motivo diverso,

per salvaguardare le reazioni digestive

che richiedono un pH
molto più basso di quello

covato dal citoplasma.

Anche i mitocondri hanno un interno acido,

tra le loro due membrane

che aiutano a produrre energia.

Nel complesso, la classificazione
delle cellule eucariote

sostiene azioni che altrimenti

sarebbero incompatibili se
eseguite simultaneamente

senza una forma di contenimento.

Gabaldón, Toni e Alexandros A. Pittis. "Origine ed evoluzione della compartimentazione subcellulare metabolica negli eucarioti". Biochimie 119 (dicembre 2015): 262–68. [<a href="https://doi.org/10.1016/j.biochi.2015.03.021" target="__blank">Sorgente</a>]

compartimentalizzazione eucariotica

Una delle caratteristiche distintive delle cellule eucariotiche è che contengono organelli legati alla membrana, come il nucleo e i mitocondri, che svolgono particolari funzioni. Poiché le membrane biologiche sono permeabili solo a un piccolo numero di sostanze, la membrana intorno a un organello crea un compartimento con condizioni controllate all'interno. Questi microambienti sono spesso distinti dall'ambiente del citosol circostante e sono su misura per le funzioni specifiche dell'organello.

Ad esempio, i lisosomi, gli organelli nelle cellule animali che digeriscono molecole e detriti cellulari, contengono un ambiente più acido del citosol circostante, perché i suoi enzimi richiedono un pH inferiore per catalizzare le reazioni. Allo stesso modo, il pH è regolato all'interno dei mitocondri, che li aiuta a svolgere la loro funzione di produrre energia.

Inoltre, alcune proteine richiedono un ambiente ossidativo per una corretta ripiegatura e processamento, ma il citosol è generalmente riduttivo. Pertanto, queste proteine sono prodotte da ribosomi nel reticolo endoplasmico (ER), che mantiene l'ambiente necessario. Le proteine vengono spesso trasportate all'interno della cellula attraverso vesciche legate alla membrana.

Il materiale genetico delle cellule eucariotiche è compartimentato all'interno del nucleo, che è circondato da una doppia membrana chiamata involucro nucleare. Piccoli pori nella busta controllano quali molecole o ioni possono entrare o uscire dal nucleo. Per esempio, l'RNA messaggero (mRNA) esce dal nucleo attraverso questi pori per portare le istruzioni genetiche codificate nel DNA ai ribosomi, dove possono essere tradotte in proteine.

Gli Organelli possono anche proteggere una cellula contenendo e neutralizzando sostanze pericolose. Ad esempio, i perossisomi eseguono reazioni di ossidazione che producono perossido di idrogeno, che è tossico per le cellule, ma contengono anche enzimi che lo convertono in ossigeno e acqua innocui. Pertanto, la compartimentazione consente alle cellule eucariotiche di svolgere una varietà di funzioni diverse che altrimenti sarebbero incompatibili in termini di ambienti richiesti o sottoprodotti prodotti.

Compartimentalizzazione eucariotica

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Education

Didattica

JoVE Core

Molecular Biology

Biologia Molecolare

Unit 1

Unità 1

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DNA, cellule ed evoluzione

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

Eukaryotic Compartmentalization

cell compartments in eukaryotes

Eukaryotic cells use compartments to organize many different jobs inside one cell. These compartments help separate processes so they can happen in the right place.

The compartment called the cytosol is the fluid part of the cell. It surrounds the other internal structures and helps support many cell processes.

Inside the cell, membrane-bound organelles create distinct microenvironments. A microenvironment is a small internal space with conditions that fit a specific task. This separation lets the cell run different reactions at the same time.

The nucleus is one of the main compartments in eukaryotic cells. It keeps the cell’s genetic material in a protected space and helps separate DNA-related activities from other work in the cytosol.

Compartmentalization is a key feature of eukaryotic cells. It improves organization and helps the cell control where important processes take place.

Cell Compartments in Eukaryotes

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eukaryotic compartmentalization

Eukaryotic cells use compartments to organize many different jobs inside one cell. These compartments help separate processes so they can happen in the right place. The compartment called the cytosol is the fluid part of the cell. It surrounds the other internal structures and helps support many cell processes. Inside the cell, membrane-bound organelles create distinct microenvironments. A microenvironment is a small internal space with conditions that fit a specific task. This separation...

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How Gene Families Evolve and Diversify

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key terms and concepts

Learn how eukaryotic cells use the cytosol, nucleus, and membrane-bound organelles to create microenvironments and organize cell processes.

Cell Compartments in Eukaryotes | JoVE K12

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Le video animazioni di JoVE Core Molecular Biology, organizzate in video lezioni, illustrano i processi molecolari cellulari in maniera chiara e concisa. Inoltre, nei video di "scienziati in azione", i concetti scientifici vengono applicati e dimostrati da ricercatori attraverso esperimenti in laboratorio.

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Cell Compartments in Eukaryotes

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