Download Chapter 4.1

Chapter 4.1
Introduction to the cell
Robert Hooke
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1665
used a microscope to examine a piece
of cork. (dead cells)
He described it as consisting of “a
great many little boxes”.
These “little boxes” reminded him of
the small rooms in which monks lived,
so he called them cells
Anton van Leeuwenhoek
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1674
First person to observe living cells
(single-celled organisms in pond
water)
Dutch microscope maker
Matthias Schleiden
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1838
German botanist
Concluded that all plants are made of
cells
Theodor Schwann
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1839
German scientist
Concluded that all animals are made
up of cells
Rudolf Virchow
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1855
German physician
Proposed that all cells come from
existing cells
Janet Plowe
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1931
demonstrated that the cell membrane
is a physical structure, not just an
interface between two liquids
Lynn Margulis
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1970
Proposed the theory that certain
organelles were once free-living cells
themselves
Theory:
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ENDOSYMBIOSIS
The Cell Theory
3 parts of the theory:
1. All living things are composed of 1 or
more cells
2. Cells are the basic units of structure &
function in an organism
3. Cells come only from the reproduction
of existing cells
PLANT CELL!
ANIMAL CELL!
Cell Diversity
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Your body contains at least 200
different cell types.
Size of cells
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Cells are limited inside by the ratio
between their outer surface area and
their volume
Why don't we get Giant
Cells?
Internal Organization
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Organelles- a cell component that
performs specific functions for the cell.
Cell Membrane
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Cell membrane- thin membrane
surrounding the cell
Prokaryotes
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Lack a membrane-bound nucleus
Example: all bacteria
Eukaryotes
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Has a nucleus & organelles
Examples: plant and animal cells