Cells
Theory, Structure, Function
What is a Cell?

The smallest unit
that can carry on all
the processes of life
Robert Hooke

1665 Cork Cells


“A lot of little boxes”
Dead Cells
Anton van Leeuwenhoek

1673


Hand lens
First live cells
Schleiden

1838

observed that plants
are composed of
cells
Schwann

1839

observed that all
animals are
composed of cells

Yes humans are
animals
Virchow

1858

observed that cells
come from other
cells (reproduction)
Cell Theory
1. All living things are made of one or
more cells.
 2. The basic unit of structure and
function within an organism is the cell.
 3. All cells arise from existing cells.

Create a Timeline

Must include:



Accurate time increments
4 Pictures
Descriptions of each scientist
accomplishment
Schleiden
 Hooke
 Van Leeuwenhoek

Schwann
Virchow
What is a Prokaryote?



An organism that
lacks a nucleus
Lacks other
membrane bound
organelles
Ex. Bacteria
What is a eukaryote?




Organism that has a well defined nucleus
Contains membrane-bound organelles
Some Specialized cells can function
without a nucleus, Ex. Red blood cells
Ex. Plants, Fungi, Animals, Humans
Create a T-Chart

With your shoulder partner create a Tchart that state the Differences
between Prokaryotes and Eukaryotes.
Prokaryotes
Eukaryotes
1.
2.
3.
1.
2.
3.
What are the two types of
organisms?

Unicellular – a complete living organism
that consists of only one cell


Examples – bacteria
Multicellular – a living organism
consisting of more then one cell

Examples – animals, plants
Level of Organization

Cell  tissue  Organ  Organs
system  Organism
What is an organelle?

A cell component that performs specific
functions

Example – nucleus, cell membrane
Cell Membrane

The outer boundary
of the cell
Gives shape and
flexibility to the cell
Is semi-permeable

Security guard


Mitochondria


Breaks down food
molecules and
releases energy in
the form of ATP
Battery/Generator
Chloroplast
Only found in Plants
 Green
 Site of Photosynthesis

Golgi Apparatus




Receives proteins from
ER and chemically
modifies them
Processes, packages,
and secretes cell
products
Uses vesicles for
transport
UPS
Ribosomes

The site of protein
synthesis
Can be attached to
the ER or float loose
in the cell

Line workers

Endoplasmic Reticulum (ER)





Rough ER with
ribosomes
Smooth ER w/out
ribosomes
Prepares proteins for
export
breaks down toxic
substances;
Can be rough or
smooth
Lysosome
Contains digestive
enzymes
 Digests and rids the
cell of waste
 Prevents bacteria
and viruses from
invading
 Performs:
Program Cell Death

Nucleus




The cells brain
Contains
chromosomes (DNA)
Involved in protein
synthesis
Boss/Manager
Nucleolus


The nucleolus is
within the nucleus.
ribosome RNA are
synthesized
Cell Wall





Only in plant cells
Thicker then the
membrane
Relatively inflexible
Protects and
supports the cell
Block wall
Cytoplasm


Semi-fluid material
inside a cell
Nutrient rich
Major cell organelles

Cilia and Flagella


Hair-like organelles that extend beyond the
surface of the cell
Assist in movement
Vacuole





Sack of fluid surrounded
by a membrane
Stores food, enzymes or
waste.
Animals cells typically
have many small ones
Plant cells typically have
one large one
Storage closet
Plant cell vs. Animal cell

Plant Cells have:



Cell Wall
One Large vacuole
Plastids (stores food or pigment which give
color to plant)

Chloroplast

Solar panel
Closing Quiz
1.
2.
3.
4.
Cells
Which organelle propels a cell through an
environment? Hint there are two possible
answers.(1 pt)
Which organelle is the final processing
center for a protein? (1pt)
Which three organelles are present in plant
cells but not animal cells? (3 pts)
What is the difference between a
prokaryote and a eukaryote? (1 pt)