Cell Structure
& Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
Cell Theory
• All living things are made up of cells.
• Cells are the smallest working units of all living
things.
• All cells come from preexisting cells through cell
division.
Prokaryote vs. Eukaryote
Prokaryote-single celled organism without a nucleus.
Examples: Bacteria, Archaea
Eukaryote-multicellular organism with a nucleus.
Examples: plants and animals
Bacterium-found in food, air, and
in the body
Archaea-found in extreme
conditions:
1. Extreme hot/cold
2. Methane-makers
3. Salt-loving
They differ from bacteria
by their ribosomes and
where they live.
Definition of Cell
A cell is the smallest unit that is
capable of performing life functions.
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
Two Types of Cells
•Prokaryotic
•Eukaryotic
Prokaryotic
• Do not have structures
surrounded by
membranes
• Few internal structures
• One-celled organisms,
Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic
• Contain organelles surrounded by membranes
• Most living organisms
Plant
http://library.thinkquest.org/C004535/eukaryotic_cells.html
Animal
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Cell Parts
Organelles
Surrounding the Cell
Cell Membrane
• Outer membrane of cell
that controls movement in
and out of the cell
• Double layer
http://library.thinkquest.org/12413/structures.html
Cell Wall
• Most commonly found
in plant cells & bacteria
• Supports & protects cells
http://library.thinkquest.org/12413/structures.html
Inside the Cell
Nucleus
• Directs cell activities
• Separated from cytoplasm by
nuclear membrane
• Contains genetic material –
DNA
• In both plant and animal cells
• Oreo cookie was used for
nucleus
Nuclear Membrane
• Surrounds nucleus
• Made of two layers
• Openings allow material
to enter and leave
nucleus
http://library.thinkquest.org/12413/structures.html
Chromosomes
• In nucleus
• Made of DNA
• Contain instructions for
traits & characteristics
http://library.thinkquest.org/12413/structures.html
Nucleolus
• Inside nucleus
• Contains RNA to build
proteins
http://library.thinkquest.org/12413/structures.html
Cytoplasm
• Gel-like mixture
• Surrounded by cell membrane
• Contains hereditary material
Endoplasmic Reticulum
• Moves materials around in
cell
• Smooth type: lacks
ribosomes
• Rough type (pictured):
ribosomes embedded in
surface
http://library.thinkquest.org/12413/structures.html
Ribosomes
• Each cell contains
thousands
• Make proteins
• Found on ER & floating
throughout the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Produces energy through
chemical reactions – breaking
down fats & carbohydrates
• Controls level of water and
other materials in cell
• Recycles and decomposes
proteins, fats, and
carbohydrates
http://library.thinkquest.org/12413/structures.html
Golgi Bodies
• Protein 'packaging plant'
• Move materials within
the cell
• Move materials out of
the cell
http://library.thinkquest.org/12413/structures.html
Lysosome
• Digestive 'plant' for
proteins, fats, and
carbohydrates
• Transports undigested
material to cell membrane
for removal
• Cell breaks down if
lysosome explodes
http://library.thinkquest.org/12413/structures.html
Centrioles
• Centrioles are found
in animal cells and help
to organize the
assembly of
microtubules during
cell division
Vesicles
• The main function of the
vesicle is to break down
substances in the cell
into smaller molecules.
Vesicles are small cell
organelles that are
mostly found in the cells.
Vacuoles
• Membrane-bound sacs
for storage, digestion,
and waste removal
• Contains water solution
• Help plants maintain
shape
http://library.thinkquest.org/12413/structures.html
Chloroplast
• Usually found in plant
cells
• Contains green
chlorophyll
• Where photosynthesis
takes place
http://library.thinkquest.org/12413/structures.html
http://www.cellsalive.com/cells/cell_model.htm
ORGANELLE FUNCTION
P/A/B?
Cell membrane Controls movement in and
out of cell
Cell wall
Gives structure and shape to
cell
nucleus
“brain”, control center
Nucleolus
Makes ribosomes
B
Cytoplasm
“jelly-like”, where all cell
activity takes place
ER(endoplasmi “hallways”, transports
c reticulum
materials in and out
Ribosomes
Proteins
B
Mitochondria
B
“Powerhouse”
P
B
B
B
B
ORGANELLE FUNCTION
P/A/B?
Golgi bodies
Packages proteins
B
Lysosome
“cleaners” take care of waste B
Vacuole
Large Central
Vacuole
Chloroplast
Stores food and water
Stores food/water
B
P
Where photosynthesis takes P
place
ORGANELLE
Golgi bodies
Lysosome
Vacuole
Large Central Vacuole
Chloroplast
Cell membrane
Cell wall
nucleolus
cytoplasm
Endoplasmic Reticulum
Ribosomes
mitochondria
nucleus
FUNCTION
Plant/Animal/
Both?
Save Fred!!!
Save Fred!
Write a hypothesis as to how you
will save Fred from the depths of
the ocean! Remember to write it
in an “if/then” statement.
Save Fred!!
1. Work with your table to save Fred.
2. Follow rules!
a. Fred, the boat, the life preserver can
be
touched ONLY by the paperclips,
NO HANDS!
b. Only 1 paperclip/saver
c. Diagram of how you saved Fred
d. A detailed protocol (directions)
describing
the diagram.
Save Fred…
3. Analyze and conclude experiment
(a. discuss the difficulty of the task
b. what other strategies you and your partner worked
on before you succeeded, and
c. what you think the critical steps were to solve the
problem).
Writing a Conclusion
Your conclusions summarize how your results support or
contradict your original hypothesis:
•Summarize your science fair project results in a few
sentences and use this summary to support your conclusion.
Include key facts from your background research to help
explain your results as needed.
•State whether your results support or contradict your
hypothesis. (Engineering & programming projects should state
whether they met their design criteria.)
•If appropriate, state the relationship between the independent
and dependent variable.
•Summarize and evaluate your experimental procedure,
making comments about its success and effectiveness.
•Suggest changes in the experimental procedure (or design)
and/or possibilities for further study.