1. Unit 1: The Structure and Function of Cells
S7L2.  Students will describe the structure and function of cells, tissues, organs, and organ systems.
a) Explain that cells take in nutrients in order to grow and divide and to make needed materials.
b) Relate cell structures (cell membrane, nucleus, cytoplasm, chloroplasts, mitochondria) to basic cell functions.
c) Explain that cells are organized into tissues, tissues into organs, organs into systems, and systems into organisms.

2. Two Types of Cells Prokaryotic Cells Eukaryotic Cells No Nucleus
Very simple cells
Bacteria and Archaea Only
Have a Nucleus
More complex cells
Plants, Animals, Protists, Fungi

3. Two Types of Cells Prokaryotic Cells: no nucleus
All prokaryotes are unicellular.
Bacteria – live almost anywhere
Archaea – live in extreme conditions
Has a cell membrane, cell wall, ribosomes, and DNA.
DNA strand floats in the cytoplasm.

4. Two Types of Cells Eukaryotic Cells: have a nucleus
Eukaryotes are more complex organisms; unicellular and multicellular.
Have a nucleus, DNA, organelles, ribosomes, cell membrane, (plants and fungi also have a cell wall).
DNA is located in the nucleus.

5. Cell Theory & History A cell is the basic unit of all living things.
Unicellular: composed of one cell.
Multicellular: composed of many cells
A cell is the smallest unit that can perform all the functions necessary for life. Unicellular – all functions of organism happen in one cell. Multicellular – cells are specialized to complete different jobs, but work together to function as one organism. The average human being is composed of around 100 Trillion individual cells!!! It would take as many as 50 cells to cover the area of a dot on the letter “i”

6. Discovery of Cells
Robert Hooke discovered cells while looking at a thin slice of cork through a microscope.
Robert Hooke, English Scientist, discovered cells in 1665 using a microscope he built (30x). Cork comes from the bark of cork trees. Hook described cells as tiny boxes or a honeycomb. The boxes reminded him of the small rooms or ‘cells’ that monks lived in. He thought only plants and fungi had cells because they have cell walls. Animal cells do not have a cell wall, making them harder to see.

7. Discovery of Living Cells
Anton van Leeuwenhoek discovered single-celled organisms in pond scum.
He called them “animalcules” or tiny living things.
He was also the 1st to look at blood and bacteria.
In 1673, Anton van Leeuwenhoek used his own built microscope to view pond scum (300x). In it, he discovered what he called “animalcules” or tiny living things. What he saw was single-celled, or unicellular organisms. He also observed blood cells from fish, birds, frogs, dogs, and humans
Therefore, it was known that cells are found in animals as well as plants.
“animalcules”  Protists

8. Spontaneous Generation??
Before the 1800’s, most scientists believed in spontaneous generation, meaning that cells came from something that was not alive.
Redi and Pasteur conducted experiments that proved this thinking to be wrong.
In 1673, Anton van Leeuwenhoek used his own built microscope to view pond scum (300x). In it, he discovered what he called “animalcules” or tiny living things. What he saw was single-celled, or unicellular organisms. He also observed blood cells from fish, birds, frogs, dogs, and humans
Therefore, it was known that cells are found in animals as well as plants.

9. In 1673, Anton van Leeuwenhoek used his own built microscope to view pond scum (300x). In it, he discovered what he called “animalcules” or tiny living things. What he saw was single-celled, or unicellular organisms. He also observed blood cells from fish, birds, frogs, dogs, and humans
Therefore, it was known that cells are found in animals as well as plants.

10. 3 Discoveries that led to Cell Theory
Schleiden concluded that all plants are made of cells.
Schwann concluded that all animals are made of cells.
Virchow was the 1st to view cell division.

11. Cell Theory All organisms are made of one or more cells.
All cells come from existing cells.
All organisms are made of one or more cells.
The cell is the basic unit of all living things.
Many Scientists made discoveries about cells between 1665 and the mid 1800s to contribute what is now know as the Cell Theory.
Before 1800s, most scientists believed in SPONTANEOUS GENERATION, meaning that cells came from something that was not alive.

12. Concept #2 – Different cells in a polar bear’s body do different jobs so it can survive. Example: Fat cells provide insulation and energy, while red blood cells carry oxygen.

13. Let’s Review
1) Who was one of the first people to observe cells? He is the one that named them “cells”.
Robert Hooke
2) Who named the tiny moving creatures that he saw “animalcules?”
Anton van Leeuwenhoek
3) Who concluded that all plants are made up of cells?
Schleiden

14. Let’s Review… more
4) Who concluded that all animals are made up of cells?
Schwann
5) Who proposed that all cells come from other cells?
Virchow
All organisms are made of one or more cells.
Cells are the basic unit of all living things.
All cells come from existing cells.
6) What are the 3 statements that make up the Cell Theory?

16. Cell Membrane is the layer that covers and protects a cell
Cell Membrane is the layer that covers and protects a cell. It controls what goes in and out of a cell.