Discovery of Cells

People 1660- Robert Hooke invented the microscope;

1665-he looked at a piece of cork and noticed it was made up of little boxes. He called them “cells” which means “little rooms”

in Latin. He thought cells were found only in plants and

fungi.

1683- Anton van Leeuwenhoek- first person to see bacteria and

blood cells.

CELL THEORY 1839- Theodore Schwann- came up with

the first two parts of the cell theory.

1. All organisms are composed of one or more cells.

2. The cell is the basic unit of life in all living things.

Third part of Cell Theory 1858- Rudolf Virchow- developed the third part of

the cell theory.

3. All cells come from existing cells.

All Cells Have Cells come in many different

shapes and sizes, just like humans. All cells have several similarities. All have:

1. Cell membrane2. Heredity material- DNA3. Cytoplasm and organelles4. Small in size.

Cell membrane

All cells are surrounded by a cell membrane.

Acts as a barrier between the inside and outside of the cell.

Controls the passage of materials in and out of the cell.

Heredity material

DNA= heredity materialCells reproduce and pass

DNA from one cell to the next.

Cytoplasm & Organelles Cytoplasm- the fluid that surrounds the

organelles. (mostly water) Organelles- are structures inside the cell.

Each organelle has a job and purpose.

Small in sizeThe smaller the cell, the more

surface space it has.The smaller the cell is, the

quicker material can enter and exit the cell.

An elephant is larger in size but its cells are not larger than yours, it just has more cells!

Two types of cells

Prokaryotic Eukaryotic

Prokaryotic cells

Cells with no nucleus, but has DNA.

Smallest cells bacteria Bacteria probably the first cells on

Earth 3.5 billion years old.

Eukaryotic Cells

More complex About 10 X larger than prokaryotic cells. About 2 billion years old. All living organisms are eukaryotic

except bacteria. Have a nucleus with DNA in it.

1. Lysosome

2. Mitochondria

3. Nucleus

4. Ribosomes

5. Vacuole

6. Chloroplast

7. Cell membrane

8. Cytoplasm

9. Cell Wall

Fungus Cell Wall - Chitin

Plant Cell Wall - Cellulose

10. Endoplasmic Reticulum

11. Golgi Complex

12. Vesicle

13. DNA - Chromosomes