1. 7-1 Life is Cellular

2. What is a Cell
Smallest unit of structure making up every living thing.
What does this mean?
Can’t be considered “living” unless you have the properties of at least one cell
Lowest common denominator of all living things – the cell
Development of Cell Theory

3. The Cell Theory Historically, how did it develop?
Anton van Leeuwenhoek (1600)
developed the microscope and saw tiny living organisms in a drop of water
learned to grind lenses and put them to together in combinations to magnify things
was a businessman who originally developed microscope to examine threads
1st to see blood cells, bacteria, sperm cells

4. The Cell Theory Robert Hooke (1665)
looked at cork under microscope and thought they looked like tiny chambers
first to coin the term “cells” – in reference to monastery rooms called cells

5. The Cell Theory Mathias Schleiden (1838)
Concluded that all plants are made of cells

6. The Cell Theory Theodor Schwann (1839)
Concluded that all animals made of cells

7. The Cell Theory Rudolph Virchow (1855)
Observed cells dividing and replicating
concluded that all cells come from pre-existing cells

8. Basic Cell Structures
Despite a variety of sizes, shapes, and specific cell roles, certain structures are common to almost all cells:
Cell membrane (all cells)
Cytoplasm (all cells)
Cell wall (many cells, notable exception are animals)
Nucleus (most cells, notable exception prokaryotes – bacteria)

9. Basic Cell Structures
Cell Membrane – thin flexible barrier around cells.
Cell Wall – a strong layer around the cell membrane
Nucleus – contains the cells genetic material and controls cell activities
Cytoplasm – material inside the cell, NOT including nucleus

10. Prokaryotes and Eukaryotes
A way of classifying cells
Prokaryotes
Cells that lack a nucleus
Bacteria, e. coli, staph
Eukaryotes (you are a eukaryote)
Cells contain a nucleus AND usually specialized structures called organelles
Plants, animals, fungi, and many microorganisms

11. Prokaryotic and Eukaryotic Cells
Section 7-1
Cell membrane
Cytoplasm
Prokaryotic Cell
Nucleus
Eukaryotic Cell
Organelles
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