Organelle Name: Nucleus Nucleus Whoa, what s that huge ball in the middle of the cell? It s pretty big, so it must be important. This organelle is called the nucleus (new-klee-us), and it s the cell s control center. It directs all of the cell s activities by giving orders to the other cell parts. How does the nucleus know how to direct the cell? It contains the cell s DNA the genetic material that explains how to build and run every organism. Your DNA is like your blueprint. It has the instructions for everything from how to breathe to what color your eyes will be. You can think of the nucleus as the brain of the cell, or like the central office of a factory. Just like the central office directs the activities of the whole factory, the nucleus determines everything the cell does!
Organelle Name: Cell Membrane Cell Membrane Before you even start your journey, you have to make it inside the cell. And that s easier said than done you have to get through the cell membrane! The cell membrane is the boundary that separates the cell from the outside environment. It controls what substances come into and out of a cell. Everything the cell needs, such as food and oxygen, comes in through the cell membrane. Items the cell has to send out, such as waste and proteins for the rest of the body, leave through the cell membrane. Harmful materials that could hurt our bodies can t make it through. You can think of the cell membrane as like the door and security guard of a factory. Just like the door and security guard determine what gets in and what gets out, the cell membrane determines what enters and exits a cell.
Organelle Name: Mitochondria Mitochondria See those rod-shaped structures ahead of you? Those organelles are mitochondria (my-toe-kahn-dree-uh), the powerhouses of the cell. They convert energy in food to energy the cell can use to carry out its tasks. The mitochondria are important because cells need energy to do everything. Need to reproduce? Need to break down food? Need to get rid of waste? You d better have some mitochondria producing energy, or none of that stuff can happen! You can think of the mitochondria as like the power generator of a factory. Just like the power generator produces the energy the factory needs to make chocolate, the mitochondria produce the energy the cells need to do all of its jobs.
Organelle Name: Endoplasmic Reticulum Endoplasmic Reticulum Uh-oh, did we get lost? It looks like we re in a big maze. We must be in the endoplasmic reticulum (en-dough-plaz-mik rih-tik-yuh-lum). This organelle is a series of passageways that carry materials from one part of the cell to another. For example, when the cell s ribosomes make proteins, the endoplasmic reticulum (or ER, for short) carries them to other parts of the cell. The ER makes sure everything moves quickly through the cell to where it needs to go! You can think of the endoplasmic reticulum as just like the conveyor belt in a factory (and remember, a conveyor belt is like the thing in a grocery store that moves your groceries from the cashier to the bagger). Just like the conveyor belt carries materials around a factory, or the thing at the grocery store moves your groceries, the endoplasmic reticulum moves materials around a cell.
Organelle Name: Ribosomes Ribosomes As we re making our way through the cell, we re noticing small round objects all over. These are ribosomes, small factories in the cell that make proteins. Proteins are very important chemicals because they are one of the main building materials for new cells. Ribosomes are found in two places in the cell. Some float free in the cell s cytoplasm. Others are attached to the endoplasmic reticulum. Either way, these ribosomes make proteins the cell needs to build new parts! You can think of the ribosomes as like the chocolate-making machines in Mr. Wonka s factory. Just like the chocolate-making machines make chocolate, a cell s ribosomes make proteins.
Organelle Name: Golgi Body Golgi Body What the heck are those? It looks like a whole bunch of flattened tubes and bags. Must be the Golgi Body (pronounced gole-gee). The Golgi Body takes materials the cell makes, packages them, and sends them to other parts of the cell or outside the cell. The most common materials the Golgi Body deals with are proteins. Proteins are an important building material for new cells. They are made by ribosomes, but it s the Golgi Body s job to send them where they need to go! You can think of the Golgi Body as like the packaging and shipping center in a factory. Just like the packaging and shipping center takes the chocolate the factory makes it and sends it on to stores, the Golgi Body packages what the cell makes to send it various places.
Organelle Name: Vacuoles Vacuole All over the cell, we re finding lots of round containers filled with stuff. These must be vacuoles (vak-you-ohl). The vacuoles are large sacs within a cell that are used to store food, water and other important substances. Vacuoles often store raw materials the cell needs to live, like food (which the cell needs to make energy) and water (which we need to perform many of our body s functions). Other vacuoles store waste products until the cell can get rid of them. While animal cells often have many vacuoles, plant cells have just one big one! You can think of the vacuoles as like the storage area in a factory. Just like the storage area holds finished chocolate and raw materials like sugar, the vacuoles store important materials, too.
Organelle Name: Lysosomes Lysosome Wait, what was that? It looked like one of those vacuole storage tanks, but much smaller. Must be a lysosome (lie-suh-sohm)! The lysosomes are small, round tanks that contain chemicals that break down materials in the cell. Some lysosomes break down food into smaller pieces. Others break down old cell parts and release what they were made of so they can be used again. Lysosomes do this by using chemicals called enzymes, which can break down any part of the cell! You can think of the lysosomes as like the recycling center in a factory. Just like the recycling center breaks down old factory parts so they can be re-used, the lysosomes break down old cell parts.
Cell Part: Cytoplasm Cytoplasm As soon as we enter the cell, it feels like we re moving through jello. This must be the cytoplasm (sigh-toe-plah-zim). Cytoplasm is the thick, jello-like fluid that fills a cell. The cytoplasm flows around the cell carrying the cell s parts all of the organelles. The cytoplasm is about 80 percent water and 20 percent chemicals. Because it s mostly water, the cytoplasm is usually clear. And since the cytoplasm contains the organelles, it s where most of the cell s activities take place! You could say cytoplasm is like air, because it fills the whole factory. Another way you could think of cytoplasm is that it s like a fruit jello cup. The jello itself is the cytoplasm, and the fruit it holds in it are all of the cell s organelles.