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.

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.

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.

The keeping of bees is like the direction of sunbeams.

All I can say is what I believe.

There are a lot of people who really abused sampling and gave it a bad name, by just taking people's entire hit songs and rapping over them. It gave publishers license to get a little greedy.

Don't you dare get to the top and not know what to do.

The seeds of a redwood are released from cones that are about the size of olives. The heartwood of the tree is a dark, shimmery red in color, like old claret. The wood has a lemony scent and is extremely resistant to rot.

There are many persons who look on Sunday as a sponge to wipe out the sins of the week

I really enjoy my life in Manchester, my training, my games, everything.

Part of becoming a little bit older and having the opportunities that I have, you want to start giving back to people who have been influential and helped you along the way.

Feminism is what I do with my life its how I spend my days its my job its not just an opinion I have among many other opinions.

The nominee is Mitt Romney. Paul Ryan joins Mitt Romney. The budget plan, the approach on Medicare and all of that is going to be the Romney plan. What he has is a man as his number two who understands the details of budgets, who has demonstrated a willingness to take on tough issues.

I don't believe in regrets; I believe your future is in your tomorrows.

Abraham Lincoln went through 12 generals before he got Ulysses S. Grant. He had never done a Civil War before.

I'm an incurable romantic, and Casablanca's one of the most romantic pictures I've ever seen - the combination of Bogart and Bergman is just magical.

My view is that we should go back to the moon, build up the infrastructure to make flights there commonplace - be comfortable with it - then use that infrastructure to expand and go to Mars.

It is this research into pure painting that is the problem at the present moment. I do not know any painters in Paris who are really searching for this ideal world.

I always wanted to be a medical doctor, and I never thought of business.

I was a grunt, walking around in the jungle of Vietnam, trying not to find the enemy. Because I am so big, they were going to give me either a heavy radio or a huge machine gun to carry. I carried a radio.

A lot of groups spend their whole cultural and aesthetic identity trying to move away from Africa, which I think is a mistake. One of the reasons I love Cuba and cultures like that is because they're not trying to move away from their African roots, they're trying to embrace them. That's part of the culture.

Given the historical power differential between blacks and whites, blacks are required to be attentive to the way their white counterparts see themselves in relation to people of color if they want to survive and even thrive.

We are in the society of the teacher-judge, the doctor-judge, the educator-judge, the 'social-worker'-judge; it is on them that the universal reign of the normative is based; and each individual, wherever he may find himself, subjects to it his body, his gestures, his behavior, his aptitudes, his achievements.

I feel very comfortable shooting music, and I think you can see that.

I like visualizing a lot, so the night before a competition and right before, I will visualize myself. I'll close my eyes, turn away from everybody, and just see myself doing exactly what I want to accomplish.

I'm 16 now, I was 15 when it happened... and the encryption code wasn't in fact written by me, but written by the German member. There seems to be a bit of confusion about that part.

We heard stories about fakery and decoys at revivals. I never personally saw any trickery.