1. The Cell Theory Important Scientists:
Robert Hooke – (1665) observed thin slices of cork and saw a lot of little boxes he called “cells”
Anton van Leeuwenhoek – (1674) observed live cells in pond water and called them “animalcules”

2. Mattias Schleiden – (1838) concluded that plants are made of cells
Theodor Schwann – (1839) concluded that animals are also made of cells
Rudolph Virchow – (1858) determined that cells come only from other cells

3. The Cell Theory All living things are made of 1 or more cells.
2. Cells are the basic units of
structure & function in
organisms.
All cells arise from existing
cells.

4. Common Cell Features:
cell membrane – outer boundary of a cell that encloses the cell & separates the cell interior from its surroundings; it regulates what enters and leaves the cell.
cytoplasm – the cell’s interior; jelly like substance; contains or holds cell’s structures
ribosomes – cellular structures on which proteins are made
DNA – provides instruction for making proteins; it regulates cellular activities and enables cells to reproduce

5. Prokaryotes Single celled organisms ex: bacteria NO nucleus
NO membrane bound organelles
Contains a single circular molecule of DNA
Many have cell walls that surround the cell membrane; it provides support and structure
Some cell walls are surrounded by a capsule which is composed of polysaccharides
Many have flagella which enables it to move

6. Eukaryotes Single or multicellular organisms ex: plant or animal cells
Has a nucleus with DNA inside; linear DNA
Has membrane bound organelles that carry our specific activities
Have cilia; tiny hair-like structures
Has cytoskeleton (protein fibers) that gives the cells shape and support

7. Eukaryote vs. Prokaryote (Eukaryotic Cell vs. Prokaryotic Cell)

8. Eukaryotic Cell

10. What’s different about each cell?
DNA
(DNA)
Membrane-bound