A cell is a very tiny particle that makes up everything that is living. Cells make up flowers, viruses, animals, trees, germs, even you! 

Hello! My name is Emily and I will be taking my friend Izzy on an adventure through cells using my special powers to teach her all about cells and how they work. Join us for a fun ride! 

Hey Emily! Before we go, I wanted to ask you something. Don't cells have special parts called organelles that make them work?

That's right Izzy! I'll take you on an adventure through these cells and teach you about them!

EW! What am I standing in? Is this Jelly?

What you are standing in, Izzy, is called cytoplasm! Cytoplasm is actually in all cells. This jelly fills the space between the organelles inside of the cell that needs to be protected.

Emily, what kind of organelles are inside of a cell that needs to be protected?

I'm so glad you asked! Well, Izzy, first, I'm going to show you what protects the cell and how it protects! To the cell membrane!

This is called the semipermeable cell membrane!

Cool! What does it do?

The cell membrane is like the cell's protective barrier. This barrier protects by allowing whatever it wants in and out of the cell! This is called the semipermeable phospholipid bilayer. This barrier keeps danger out of the cell and keeps what the cell needs inside! The molecules may move on their own in something called passive transport, such as diffusion and osmosis! Vesicles are what the proteins are carried out of the cell in.

To get the things the cell needs, some molecules must first pass through the membrane, usually, these molecules move from a high concentration of molecules to a low concentration! Sometimes molecules go the opposite way. This is called active transport, often called the pump. When this happens, the molecules need some help from some extra energy! 

How does the cell remain calm while all of these things are moving in and out?

Remember osmosis? This process moves water in and out of the cell. This control of water is very important to keep the cell calm. This calmness is actually called homeostasis, and as long as the cell has everything it needs and nothing bad is in it because of the semipermeable bilayer, it will stay calm!

Cells have to divide to make more cells. Centrioles help a lot when a cell needs to divide. They help organize the cell when it is divided. Izzy, did you know a cell works like a factory?

Oh cool! How?

Let's start with the big boss of the cell, the nucleus!