Il reticolo endoplasmatico è costituito da un sistema di membrane; il reticolo rugoso ricoperto di ribosomi da ribosomi sintetizza le proteine e il reticolo liscio sintetizza soppratutto lipidi.

I batteri sono cellule procariote; queste cellule sono prive di membrana cellulare e possono vivere anche negli ambienti più estremi.

La parte fluida del citoplasma, il citosol, è una soluzione di ioni, piccole molecole e grosse proteine; nelle cellule eucariote metà del citoplasma è costituito da piccole strutture chiamate organuli.

Tutte le cellule sono rivestite da una membrana cellulare, formata da un doppio strato fosfolipidico; le cellule vegetali hanno anche una parete rigida costituita da cellulosa.

Le cellule Eucariote: hanno dimensioni limitate per favorire il rapporto superficie/volume e rendere le cellule metabolicamente attive.

Il nucleo, avvolto da una doppia membrana dotata di pori per poter comunicare col citoplasma, contiene il DNA sotto forma di cromatina e un nucleolo che assembla i ribosomi.

Il citoscheletro mantiene la forma della cellula, fissa gli organuli, dirige il traffico interno e le consente di muoversi; è formato da filamenti di actina, microtubuli e filamenti intermedi.

Ciglia e flagelli sono formati da filamenti proteici; servono per il movimento.

Il vacuolo è una cavità citoplasmatica contenente acqua e soluti, delimitata da una membrana; le vescicole con funzione di trasporto, sono piccole e hanno una struttura uguale al vacuolo

I lisosomi sono vescicole che racchiudono gli enzimi coinvolti nelle reazioni di idrolisi, i proteasomi sono specializzati nel demolire proteine per riciclare amminoacidi, i perossisomi contengono diversi enzimi ossidativi.

I cloroplasti svolgono la fotosintesi clorofialiana ; nei mitocondri, invece, avviene la respirazione cellullare.

I ribosomi sono sono siti presso cui vengono assemblati gli amminoacidi per la sintesi delle proteine.

L'apparato di golgi è un centro di elaborazione di molecole complesse che vengono poi avvolte in vescicole e trattenute nella cellula stessa o esportate.

I'm trying to adapt - they say you have to adapt to vertigo.

Privacy and security are those things you give up when you show the world what makes you extraordinary.

I mean, the last thing I want to do is be involved in politics.

When I was out of work when I first moved to L.A., one of the first things my husband and I did was buy season's passes to Disney, and whenever I was bummed out about work, we would go to Space Mountain, and it was like a physical injection of anti-depressants.

I do not know whether there are gods, but there ought to be.

Me, myself, personally, I like to keep myself private. I have never said I am a paragon of virtue, a model of morality. I simply do what I do.

We have this incredible ability to communicate with each other. I want to play around with it, see what this mass audience is really capable of.

I'm not into the Oscar and Emmys as much as I used to be because I'm tired of looking at people who don't look like me.

Obvious is the most dangerous word in mathematics.

But I'm not adverse to the idea of Torch Song as a musical. It would just be different. Because the play will always be there exactly as it was, and in a musical you could tell a lot of the story through songs.

I got an assistantship in physics at the University of Illinois, and I tore up my steno books.

Most people don't understand that being in the public eye is emotionally exhausting. It takes a lot out of you.

The American people know that every day 3,000 kids begin to smoke, 1,000 of them die an early death. They're not going to allow us to go forward this year and not have comprehensive bipartisan legislation. It's in everybody's best interest.

The principle of building an economy without foreign monopoly capital has become a principle which, for us, is no longer subject to amendment.

Who breathe where you will, come into me and snatch me up to yourself.

I guess thats what saying good bye is always like like jumping off an edge. The worst part is making the choice to do it. Once youre in the air theres nothing you can do but let go.

Pope John Paul II was a great presence on the stage. Pope Benedict is a much more gentle and refined person, and I think he benefits greatly from the television close-ups because he wants to engage in a dialogue, in conversation. He wants to put forward his views in a measured, eloquent, rational way.

If you wish to fly to new heights, begin by setting your sights on a destination you can reach and then create a flight plan, a map, that will be your guide.

I think that content posted to Twitter is distributed to more platforms, services, sites, online and offline than any other services out there. Would love to see if someone can prove to me otherwise.

I was the future once.

We have confused the free with the free and easy.

One way of grounding the magic is by putting in lots of stuff about street lamps, carriages, and how difficult it is to get good servants.

I think I had an advantage in the sense that I wasn't raised religiously.

I woke up and all I could see was Iraqis standing all around me, looking down upon me. I knew at that moment something terrible had happened and I wasn't in the right place.