Albert Einstein once said: “If you can’t explain something to a 6 year old, you don’t understand it yourself. “ So, the most difficult questions for a scientist sometimes come from the children themselves.
In an article in The Conversation, biologists Georgia Atkin-Smith and Ivan Poon at La Trobe University, Australia had to find a way to tell a 4-year-old boy named Bea: Cells are made up of what are the parts?
While a scientist can fully understand the structure of cells and their organelles, explaining these complex aspects to a child can be a real challenge.
Ask: “I knew that the blood vessels in the human body are made of cells, but what are cells made of?“- Bea, 4 years old.
A: That’s a great question, Bea!
The human body is like a giant jigsaw puzzle, with billions of small puzzle pieces called cells. Our cells come in many different shapes and sizes. Together, they make up all the parts of our body, from our blood vessels to our brains.
Our cells are actually very small. For example, look at your hair, it’s very thin, isn’t it. Even though the hair is already very thin, the top of the hair can still hold up to 20 cells. That’s because they are very small.
But even smaller, scientists have discovered cells are made up of even smaller pieces of the puzzle that we call molecules, such as molecules of water, plus other kinds of molecules like proteins, fats and DNA.
Like our bodies, cells have different parts and they work together. Let’s try some comparisons:
1. Cells also have skin
The outer skin of a cell is called the plasma membrane. It is made mainly from fat molecules. If you need something for you to visualize a cell’s skin, remember the Michelin logo. The fat molecules that surround the cells also form bubbles like “tire people“so.
The plasma membrane is the outer skin layer of most animal cells. But plants also have cells. In addition to the plasma membrane, plant cells have an extra layer of armor called the cell wall.
Similar to the iron armor of the knights, the armor of the plant cells was not only hard but also tough and firm. This explains why human skin is soft to the touch like a bubble, and that trees are rough to the touch. Hard cell walls are also the reason why plants can be tall and strong.
2. Cells also have bones
Like the bones inside the child’s body, the cells also have their own skeleton called a cytoskeleton. In translation, cytoskeleton means “cellular skeleton”. It is made up of protein molecules.
The cell’s skeleton makes it strong and also helps our cells to move around the body.
3. Cells also have brains
One of the most important molecules in cells is DNA, made up of bricks called nucleotides. DNA is like a guidebook for everything our cells have to do (including dividing to make more cells, moving where it needs to be and fighting off pathogens like microbes virus).
With such an important role, the DNA needs to be protected in an organization called the cell nucleus, we just call it the brain of the cells.
You may also have heard of genes. A gene is like the recipe cells use to make offspring! They decide how tall you will be, whether your eyes are black or brown, your hair is curly or straight …
All of our genes are made of DNA and we get this DNA half from our mother and half from our father. For example, if a father has brown eyes, he can pass on his DNA formula to his child.
These recipes are similar to recipes or a home blueprint, they will instruct the human cells to know how to create brown eyes. This explains why we all look somewhat like our parents.
4. Cells with stomach
When I’m hungry, I have to eat! Your baby’s stomach then breaks down your child’s food in a process called digestion. Likewise, the child’s cells also have their own small stomachs called lysosomes. The cells’ digestive organs also help them get energy from food to function and flush waste out of the cells to keep them clean and happy.
5. Cells generate energy
As noted above, our cells digest for energy. But what is energy?
Whenever you turn on the light switch, the room will light up. This is because there is a stream of energy called electricity that flows from the power plant to each home and into each appliance. We need energy to operate everything from lights, TVs, telephones, air conditioners to heaters …
Nearly everything that happens inside cells requires energy. As a result, cells have special parts called mitochondria, which are the organs that produce energy for the cells. Mitochondria are like a miniature power plant, and they supply the cells with electricity.
6. Cells can talk to each other!
Our cells are all very small and our bodies are very large. In a human body there can be up to trillions of cells. So how can all of our cells work together? The answer is they can talk …, something like that.
Instead of picking up the phones to talk to each other, our cells have to send messages. These messages are made of molecules that help cells communicate.
This is an interesting example. If your child is stung by a bee (ouch!), Their skin will start to become red and puffy. This may seem scary, but in fact, it’s my body that is helping me heal.
The cells in this swollen area are rapidly sending messages for help. Cells in other regions receive these messages and then join the rescue.
It was like a crowd of people gathered around a fire. Soon after, the rescue would be successful and the bump would disappear when everyone got home.
As a true scientist, her uncle knows a lot about cells. But the truth is that the uncle still doesn’t know everything about them. That’s why auntie needs curious kids who ask questions like Bea!