1. What is a Cell?

2. What makes up a cell?
Even though early scientists like Robert Hook could see cells through their microscopes, they had no idea how complex a cell is.
From their perspective, a cell was a simple block with a spot inside the core, which they called the nucleus.

3. What makes up a cell?
Let’s take a look at the anatomy of a cell. Cells can come in many shapes and sizes.

4. What makes up a cell?
While they are shaped differently, cells have similar parts.
Cell Membrane
The cell membrane is the gatekeeper of the cell, letting substances to pass in and out of the cell.

5. What makes up a cell?
Inside the cell membrane are tiny parts called organelles that each have a special job.
Cytoplasm
The organelles float in a nutrient filled substance called cytoplasm.

6. What makes up a cell? The cell requires power to work. Mitochondria
Nutrients from the food you eat are transformed into fuel that the mitochondria uses to power the cell.
Mostly, the fuel comes from glucose, a type of sugar.

7. What makes up a cell? The cell also needs protection. Lysosomes
The lysosomes destroy bacteria that enters the cell.
They also break down old organelles and send them out of the cell.

8. What makes up a cell? Lysosomes
The lysosomes also break down nutrients from the food you eat – like protien, the nutrient in meat, and carbohydrates, the nutrient in potatoes – into pieces the cell can use.

9. What makes up a cell? Golgi bodies
The cell needs a supply of proteins and fat.
These nutrients are stored in the Golgi bodies.
The Golgi bodies send the supplies where they are needed.

10. Pause for a minute.
What have you learned so far?

11. What makes up a cell? Endoplasmic Reticulum
When the cell needs chemicals or to eliminate waste, the endoplasmic reticulum sorts what needs to go where and sends it.
Waste is sent from the endoplasmic reticulum out of the cell.

12. What makes up a cell? Endoplasmic Reticulum
Because endoplasmic reticulum is difficult to say, most people nickname it as the ER.
Each cell will have more ER than Golgi bodies.
Some ER are studded with beads called ribosomes.

13. What makes up a cell? Centrioles
Adults have more cells than children because as you grow, your body produces more cells.
Your body also needs to repair damaged cells from when you have an accident.

14. What makes up a cell? Centrioles
Centrioles are the special organelles that can help a cell copy itself, or reproduce.

15. What makes up a cell? Nucleus
The nucleus is the largest organelle within a cell.
The outside of the nucleus is a thick, porous nuclear membrane that holds the nucleus in shape.

16. What makes up a cell? Nucleus
Inside the nucleus is a smaller ball called the nucleolus.
The nucleolus make the ribosomes that are sometimes found on the ER.

17. Pause for a minute.
Talk about what have you learned so far.

18. What is inside the nucleus?
DNA
Deoxyribonucleic acid, also called DNA, is a tiny molecule that contains all the information about a person.
DNA can be found in almost every cell in your body.

19. What is inside the nucleus?
DNA
The information within the DNA is called genes.
The genes are made up of nucleotides, which scientists refer to as the letters that spell out what a person will be like.

20. What is inside the nucleus?
DNA
DNA is packaged into groups called chromosomes, and each cell contains 46 chromosomes.
Unless the person has a twin, every person’s DNA is unique.

21. What is inside the nucleus?
How does DNA talk to the rest of the cell when it is inside the nucleus?
RNA
RNA is the messenger.
The RNA copies the code in the DNA and takes it to the ribosomes, which then prepares the protein the cell needs.

22. Pause for a minute.
Talk about what have you learned so far.

23. What can a single cell do?
An egg is an example of a single cell.
However, this one cell can become many cells when it develops into a chick.

24. What can a single cell do?
Every person starts from a single cell…
But the centrioles help the cell to divide to form a baby…

25. What can a single cell do?
In the beginning, all of the cells are exactly the same.
Soon, the cells begin to differentiate, or become different.
Cells of the same type gather together to form tissues.

26. What can a single cell do?
There are four types of tissues.
nervous tissue
(brain, spinal cord, nerves)
muscular tissue
(muscles)
connective tissue
(keeps organs and skin connected)
epithelial tissue
(skin)

27. What can a single cell do?
Tissues group together to form organs – like your stomach,
Organs connect together to form organ systems – like your digestive system,
And it all starts from a single cell.

28. Let’s review.
Talk about what have you learned today.