It's pretty straight foward it controls what gets in and out
Cell Membrane - The membrane of the cell forms an outer shell that protects it. It's function is to be semi-permeable, which means that it separates the cell from outside elements and only allows certain molecules in.
Centrosomes - Centrosomes organize microtubules, which are like hollow rods that give the cell its support and shape.
Centrioles - Centrioles are cylinders made of proteins that are found in a cell's centrosome.
Cytoplasm - This is the jelly-like substance that makes up the inside of the cell. It's not an organelle, but a material that can be found within the membrane.
Endoplasmic Reticulum - The endoplasmic reticulum, or ER for short, forms the transport system for the important proteins in the cell, like RNA. ER can be split into two groups: smooth ER and rough ER.
Golgi Complex - The Golgi complex, which is also known as the Golgi apparatus and named after the person who found it, is like the post office or packing center of the cell. It prepares proteins that need to be shipped off to specific destinations.
Lysosomes - Lysosomes are enzyme-filled sacs that digest nutrients and cell wastes.
Mitochondria - This organelle has an important job. It keeps the rest of the cell going by supplying energy in the form of adenosine triphosphate (or ATP).
Nucleus - The nucleus is a soft sac of the cell that has the responsibility of carrying its genetic code (also known as DNA).
Nucleolus - Within the nucleus is another nucleus, or nucleolus, where RNA is formed. RNA carries the messages or instructions that DNA provide.
Ribosomes - After RNA leaves the nucleolus and nucleus, it goes through the endoplasmic reticulum to the ribosomes, where protein synthesis takes place.