Cells: The Basic
Unit of Life
History of Cell Theory
• Began with the invention of
the lens in the 1600s
• Robert Hooke – First person
to observe cells
– Used cork (dead plant cells)
History of Cell Theory
• Anton von
Leeuwenhoek - First
to observe living
cells
• Scraped his own
teeth and looked at
the bacteria
History of Cell Theory
• Matthias Schleiden Found that all plants
are composed of cells
• Theodore Schwann –
Found that all animals
are composed of cells
History of Cell Theory
• Rudolph Virchow –
Developed the
theory that “all cells
come from other
cells”
Cell Theory
1. All living things are
composed of cells.
2. Cells are the basic
unit of structure
and function.
3. Cells only come
from preexisting
cells.
Two Major Types
1. Prokaryotes – no nucleus
or true organelles,
simple
a. Bacteria
2. Eukaryotes –
nucleus and
membrane-bound
organelles, more
complex
a.
b.
c.
d.
Animals
Plants
Fungi
Protists
Cells are composed of organelles
• Basic Cell Structure
– Plasma Membrane
– Cytoplasm
– Nucleus
Cells are composed of organelles
• Animal cells have many organelles in
common with plant cells
• Some organelles look and behave
differently in plant cells
Nuclear Envelope
Location:
Surrounds the nucleus
Function:
Membrane that surrounds
the nucleus. Allows
certain materials into
and out of the nucleus
Nucleolus
Location:
Inside of the nucleus
Function:
Produces ribosomes
Nucleus
Location:
Usually the center of
the cell
Function:
Control center for the
cell
Cytoplasm
Location:
Liquid/jello-material found
throughout the cell
Function:
Keeps organelles from
bumping into each other
Chromatin
Location:
Inside the nucleus
Function:
Contains DNA genetic material
Mitochondria
Location:
Found throughout the cell
Function:
Produces energy for the
cell. “Powerhouse of the
cell” shaped like a
kidney bean
Ribosomes
Location:
Found throughout the
cell
Function:
Make proteins
Rough Endoplasmic Reticulum
Location:
Attached to the
nucleus
Function:
Transport system of
the cell. Has
ribosomes attached
Smooth Endoplasmic Reticulum
Location:
Found throughout cell
Function:
Transport system of
the cell. Does not
have ribosomes
attached.
Vacuole
Locaton:
Small fluid filled sacs
throughout the cell
Function:
Hold water, waste and
food. Smaller in
animals than plants.
Golgi Apparatus
Location:
Found throughout the
cell
Function:
Series of sacs that
package and release
cell products.
Microtubules
Location:
Found throughout cell
Function:
Long, hollow straws.
Serve as the
‘skeleton’ of the cell.
Microfilaments
Location:
Found throughout cell
Function:
Long, solid, threadlike
strands that are
involved in cell
movement
Plasma Membrane
Location:
Found on the outside of
the animal cell
Function:
Serves as protection for
the cell. Allows certain
materials into and out of
the cell; ‘selectively
permeable.’
Vesicles
Location:
Found throughout cell
Function:
Contains material that is
packaged by the Golgi
apparatus. Carries
substances out of the
cell.
Lysosome
Location:
Found throughout cell
Function:
Sacs that contain strong
digestive enzymes. Also
known as ‘suicide sacs.’
Centriole
Location:
Found towards the
center of the cell
Function:
Aids in cell division.
PLANT CELLS
• Differ from animal cells
– Larger Vacuole
– Cell Wall
– Chloroplasts
Nuclear Envelope
Location:
Surrounds the nucleus
Function:
Membrane that surrounds
the nucleus. Allows
certain materials into
and out of the nucleus
Nucleolus
Location:
Inside of the nucleus
Function:
Produces ribosomes
Nucleus
Location:
Usually the center of
the cell
Function:
Control center for the
cell
Cytoplasm
Location:
Liquid/jello-material found
throughout the cell
Function:
Keeps organelles from
bumping into each other
Chromatin
Location:
Inside the nucleus
Function:
Contains DNA genetic material
Mitochondria
Location:
Found throughout the cell
Function:
Produces energy for the
cell. “Powerhouse of the
cell” shaped like a
kidney bean
Ribosomes
Location:
Found throughout the
cell
Function:
Make proteins
Rough Endoplasmic Reticulum
Location:
Attached to the
nucleus
Function:
Transport system of
the cell. Has
ribosomes attached
Smooth Endoplasmic Reticulum
Location:
Found throughout cell
Function:
Transport system of
the cell. Does not
have ribosomes
attached.
Vacuole
Location:
Takes up a large part of
the cell
Function:
Very large fluid-filled
structure that holds
water, waste and food.
Much larger in plants
than animals due to
Turgor Pressure.
Golgi Apparatus
Location:
Found throughout the
cell
Function:
Series of sacs that
package and release
cell products.
Microtubules
Location:
Found throughout cell
Function:
Long, hollow straws.
Serve as the
‘skeleton’ of the cell.
Microfilaments
Location:
Found throughout cell
Function:
Long, solid, threadlike
strands that are
involved in cell
movement
Plasma Membrane
Location:
Found on the outside of
the animal cell
Function:
Serves as protection for
the cell. Allows certain
materials into and out of
the cell; ‘selectively
permeable.’
Cell Wall
Location:
Found on the outside
of the cell
Function:
Gives the cell
protection and
shape. Made of
cellulose.
Chloroplasts
Location:
Found throughout cell
Function:
Contains chlorophyll. Place
where photosynthesis
occurs; place where cell
makes food.
Can you compare
and contrast plant
and animal cells?