1. 2
Unit 3: The Cell

2. Section 1: Cell Theory & Organelles9
The first person to see a cell needed to use a Microscope.
Section 1:
Cell Theory
& Organelles
Then, people discovered Atoms, and in the 20th Century created microscopes that used Electrons instead of light. (1933)
The microscope was invented more than 400 years ago (1590).
Afterwards, people figured out how to make Compound Light Microscopes.
The first microscopes were Simple Light Microscopes.
Magnification: This is how large an image appears.
Resolution: This is how clear an image appears.
These combine at least two lenses and allow the viewer to see even smaller objects. These are your common microscopes.
These used ONE lens to bend light to make an object appear larger.
Today, we would call this a magnifying glass.
Super magnification & Resolution!!!

3. Robert Hooke was the first person to ever see a cell. (1665)2
He was studying the Cork of an Oak tree using a compound microscope that he invented. They had no pictures or cameras back then, so he did his best to draw the things he saw. He began to see very tiny rectangular shapes that were stacked and endlessly repeated throughout the cork. These small rectangles reminded him of small rooms, so he named them cells. When he finally realized what he was looking at, he was dumbfounded at the sheer number of cells that living things contain.

4. 4
Anton Von Leeuwenhoek was the first person to see a living unicellular organism
He studied pond water and was amazed at the tiny forms of life that existed in the water that everyone was drinking. Some of the creatures were very fantastical looking. He was also quite a good artist. Anton would sketch the creatures that he saw from each angle. He also scraped people’s teeth and collected samples from finger/toe nails. He is the first person to begin to catalog all the creatures that live on and around us, yet are so small that we are unaware.

5. Well, cells are , things. Here are some examples: tiny tiny
Amoeba 7
How Big are Cells?
Well, cells are , things. Here are some examples:
tiny
tiny
1 cm2 of your skin contains 100,000 cells
The biggest single cells creatures are 1 mm wide.
Normally, cells are 100th of that size.
But, some cells (like nerve cells) can be a meter long.
Adding up the number of cells in your body is similar to trying to count the grains of sand in Hawaii.
Especially since they are dieing and multiplying constantly.
Human
Skin

6. 3

7. A cell by itself is much like a little city
A cell by itself is much like a little city. It is made up of many parts that must work together in order to stay alive.

8. An organelle is a functioning part of a cell, much like organs are functioning parts of your body.

9. There are two different types of cells:2
There are two different types of cells:
Prokaryote:
These are cells that DO NOT have a nucleus. Their DNA is loose in the cytoplasm.
Eukaryote:
These are more modern cells that HAVE a nucleus.

10. We will also explore the differences between animal and plant cells.
We will be defining the organelles and using these two pictures to see how they might look in a cell. These pictures are the last two pages of your note packet. 1
We will also explore the differences between animal and plant cells.

11. 3
Nucleus
3 parts:
Nuclear Envelope: This separates the nucleus from the rest of the cell. Sort of like the security force at the White House.
The largest, central part of the cell. This is where the genes (DNA) are found. This is the central government of the cell. It is found in both Animal & Plant cells.
Nucleolus: In charge of creating Ribosomes, which make proteins. This would be sort of like Congress.
Chromatin: loose “soupy” DNA material. This is where all bodily information is stored.