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

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 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 played the piano as a boy for six years, from the time I was six to 12 years old. My piano lessons ended when my father died because our family had no more money. I used to have a mestiza teacher. She'd come once a week to teach me piano lessons, and she'd bribe me each time with an apple; otherwise, I wouldn't play.

There's something about the intimacy of comics that gives you a false bravado; you don't always consider the consequences.

E-governance is easy governance, effective governance, and also economic governance. E-governance paves the way for good governance.

Laughter is God's blessing.

I've been on the 'Tonight Show' a million times, and I'd be embarrassed to do the same thing more than once.

It turns out that there are swaths of habitat in the north of Siberia and Yukon that actually could house a mammoth. Remember, this was a highly plastic animal that lived over tremendous climate variation.

Although we take it for granted, sanitation is a physical measure that has probably done more to increase human life span than any kind of drug or surgery.

The process of doing plays will make you an actor.

The bond between friends cannot be broken by chance no interval of time or space can destroy it. Not even death itself can part true friends.

My singing wasn't horrible, but my dancing really made it look silly. It's not like I'm a horrible singer that can't sing. But I don't have the consistency or the presentation skills that a good performer has.

It might crush a lot of people, but I've never been in the room with an artist that I've written a song for.

It took me four months in Biosphere 2 to make a pizza.

I was never encouraged to do it and I played the accordion, which I hated. I wish I had taken piano because I definitely would have written more songs of my own, but I didn't.

The wonderful thing about maths is it's a totally logical subject, and a pathway has been marked out. I think a lot of these things can be crystallised in something quite essential, that people can get. If I can't explain it, I realise that's probably because I don't completely understand it myself.

Energy independence and energy security are really two different things.

I can confirm that Poland should become a eurozone country, and not just because of the treaties that have been signed, but because I consider it of strategic interest both for Poland and the E.U.

Al Qaeda is not the organization now that it was before. It is under stress organizationally. Its leadership spends more time trying to figure out how to keep from getting caught than they do trying to launch operations.

I started off in musical theater, yeah. It was one of my first jobs; it was in Spring Awakening in London, which was amazing.

I used to say that winning the Oscar means being back at the Beverly Hills Hotel at 1 A.M. feeling empty. It's the industry voting. It doesn't come from God. It doesn't change your life, really.

Some people use excuses to not accept responsiblity others use excuses as a way to justify.

The only real treasure is in your head. Memories are better than diamonds and nobody can steal them from you

Irish people have a trick of over-statement, at which one ceases to wince as one grows older.

A manufacturing nation is, in every sense of the word, dependent on others. Look to England! Cut off from the markets of the world, misery and ruin await her.

I believe in financial retirement. I don't necessarily believe in physical retirement.