Cells are the building blocks of all life. Every living thing, be it plant, animal, or bacterial, is made from cells. They are the smallest structural and functional unit of an organism.
Just as our human bodies have organs to help us function, all cells have structures called organelles that make them function.
Heart cells are not the same as skin cells, which are not the same as the immune system’s T-cells. Regardless of what kind of cell it is, all cells have the same general structure. Let’s take a look at the organelles within an animal cell.
There are many parts to a cell, but today we are going to learn about 9 of the major parts of a cell. We are going to look at the cell membrane, cytoplasm, nucleus, nucleolus, endoplasmic reticulum, ribosomes, golgi bodies, mitochondria, and vacuoles.
The cell membrane is a thin layer of protein and fat that surrounds the cell. It is semi-permeable, which means some substances are able to pass through, though most aren’t. It’s basic purpose is to protect the cell from it’s surroundings.
Cytoplasm is a jelly-like water based substance that houses the rest of the cell’s structures. It gives the cell three-dimensional shape and provides a place for the other parts of the cell to be suspended and a medium to travel through. The cytoplasm maintains the pressure of the cell.
The nucleus is protected by a nuclear membrane. It is here, in the nucleus, that DNA is stored. The nucleus is responsible for protecting DNA as well as controlling the function of the rest of the cell. It is often referred to as the “brain” of the cell.
A nucleolus is located inside the nucleus of a cell. The primary function of the nucleolus is to assemble ribosomes and it contains the genes for pre-ribosomal ribonucleic acid (pre-rRNA), which then are combined to create ribosomes.
The endoplasmic reticulum (or ER) is made up of both the rough and the smooth endoplasmic reticulum. ER transports materials through the cell and produces proteins in sacs called cisternae. The ER is the transportation system for the cell.
Ribosomes are the protein makers of the cell. They connect amino acids together to form proteins. Some ribosomes are floating in the cytoplasm, while others are attached to the rough endoplasmic reticulum.
A flat, layered organelle that is located near the nucleus, golgi bodies gather and package simple molecules to make more complex ones. Some of these molecules are stored for later use, and others are exported from the cell.
Mitochondria create energy for the cell by breaking down nutrients. Mitochondria are rod-shaped organelles with two membranes. The inner membrane is folded over many times to create more surface area so it can make more energy.
Vacuoles are storage bubbles within a cell. Vacuoles can store nutrients for the cell to use, or they can store waste to be transported out of the cell. Waste is “packaged” in a vacuole to protect the rest of the cell.
It can be challenging to keep all these cell parts straight, so here are some fun printable pages for you to use or to use with your children when talking about cells.
Cut and Paste a Cell
Organelle Flash Cards
Download your printable animal cell activities by clicking on the image below, or get them here!
Which organelle do you think is the most interesting? What will you explore next?
This research came on the heels of learning about the difference between bacteria and viruses (because viruses aren’t live cells). Read more about that here.