The New New New Random Thread.

[jacensolo3]

hey Em

 

[marypops!]

Hello Em.

 

[CrazyChik]

Hey Em.

 

[Em&Em]

hey Em

Hello Em.

Hey Em.

Hello Brandon, George, and Hazzi. Wow finally a thread that has an equal amount of guys to girls.

 

[CrazyChik]

Aaah i'm so not making sense right now.

 

[Em&Em]

Aaah i'm so not making sense right now.

I never make sense.

 

[jacensolo3]

making sense is for squares

 

[CrazyChik]

Riding makes me really tired.

 

[CrazyChik]

Night empty thread.
xD

 

[marypops!]

Good night.

Facilitated Diffusion... sucks.

 

[MuskratSusie]

I have to go soon!

 

[ginnygirl102]

Lalalalalalalalala I'm SO hungry and I want a FUZE

 

[marypops!]

I still haven't got tea yet...

 

[marypops!]

Simple diffusion refers to a process whereby a substance passes through a membrane without the aid of intermediary. However, substances with a stong positive or negative charge and large molecules can't cross cell membranes using simple diffusion. To get in and out of the cell, they use a specialised form of diffusion called facilitated diffusion, a form of passive transport facilitated by transport proteins. It involves proteins in the membrane that allow only certain substances to move through their concentration gradient.

They might be channel proteins, which form pores throughout the membrane. Each type of channel proteins will only allow one particular type of molecule through, depending on it's shape. For example, there are sodium ion channels, which will only like sodium ion molecules through. Some channels only open when a certain molecule is present or an electrical charge passes through the membrane, like during the passage of nervous impulses along neurones.

Another form of facilitated diffusion depends on the carrier molecules floating on the surface of the membrane. They are found on the outside surface of the membrane when a substance is to be moved into the cell, and on the inside for transport out of the cell. The protein carriers are specific for particular molecules, depending on the shape of the protein carrier and the substance to be carried. Once a carrier has picked up a molecule, it rotates through the membrane to the other side, taking the molecule with it, before releasing it. The movement takes place because the carrier changes shape once it carries something. The process can only take place down a concentration gradient, from high concentration, to low concentration. It doesn't use energy, so it's considered a type of diffusion. For example, red blood cells have a carrier to help glucose move into the cells quickly.

Most of that, is copied word-for-word from the book -_- and the information on Wikipedia, is only a few sentences long.

 

[Em&Em]

I could use a spot of tea myself chap. Don't I sound British?

 

[ms.tinkerpoo]

hello

 

[Em&Em]

hello

Hello Ms. Hay lea

 

[marypops!]

http://www.hbo.com/littlebritainusa/characters/vicky.html

 

[marypops!]

WOOT! I actually understood a question in Physics!

Now the next one... Meh, maybe it's the same type of thing?

 

[MuskratSusie]

Hello.