The Cell Theory
• Developed during the mid 1600s
o The discovery of the microscopy: This was an important technological
advancement that made us know about cellular biology, this help us knew we
were made out of cells.
• All living organisms are made of cells.
• New cells are created by old cells dividing into two: every cell was a result of one cell
diving into two. The tree of life-assuming everything was coming from the origin of life
• Cells are the basic building units of life
Anthony van Leeuwenhoek created 400 microscopes, only 9 of which exist today
The original microscope was able to maximize image by 270 times
Miccrogrpahia: this book was written in 1665, talked about investigating the cellular natural
1676: He was the first person to experience bacteria from his own teeth
Figure 4.4 A bright-field, compound
Figure 4.11 A transmission electron microscope (TEM). (a) The path of electrons through a
TEM, as compared to the path of light through light
• The cell is the basic unit of all life forms
Made up of just one cells: different types of prokaryotes and eukaryotes
Bacteria, yeast etc.
Made up of several to billions of cells
Most plants and animals
These cells work together to help the organisms grow and survive Cancer is a lack of ability of cells to adapt to their environment.
Cell structure: Prokaryotic vs. Eukaryotic (picture)
Prokaryotic cells are smaller than eukaryotic cells
Eukaroyitic cells all have a nucleus, genetic material, cytoplasm,membrane organells (which
are responsible for many specific activites)
Cells can look different from others.
Skeletal muscle cells B. Motor neuron, a type of nerve cell
Figure 3-3, p. 43
The Eukaryotic Cell
The cell surface
o Plasma membrane
o Intergral membrane proteins
o Endoplasmic reticulum
o Vesicles such as lysosomes
Function of Cell Membranes
Separate the inside of a cell from the outside environment
Separate cells from one another.
Provide a surface on which chemical reactions occur. : In the membrane, there are a lot
of enzymes. There are quite a lot of receptors that listen to what goes on outsi