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.
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
Cell Membrane
• Outer membrane of cell
–Contains the cell contents
–Controls what gets in and out of the cell
–Is selectively permeable
http://library.thinkquest.org/12413/structures.html
Nucleus
• Directs cell activities- the “Control Center”
• Contains genetic material – DNA
• Usually the easiest organelle to see under
a microscope
ADD
THE
LABELS
Cytoplasm
• Gel-like mixture
• Surrounded by cell membrane
Endoplasmic Reticulum
• Moves materials around
in cell- the “Assembly line
or Roads”
• Smooth type: lacks
ribosomes
• Rough type (pictured):
ribosomes attached to
surface
http://library.thinkquest.org/12413/structures.html
Ribosomes
• Each cell contains
thousands
• Make proteins
• Found on RER &
floating throughout
the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Cellular respiration occurs
here to release energy for
the cell to use
• “Power plant” of the cell
http://library.thinkquest.org/12413/structures.html
Golgi Bodies
• Protein “packaging
plant” or “shippers”
• Coats proteins and
other materials so
they can move
different location
inside/outside of cell
http://library.thinkquest.org/12413/structures.html
Golgi Apparatus
Lysosome
• The “Clean-up Crew”
• Filled with enzymes that
break apart molecules
that are small enough for
cell to use
• Get rid of wastes “garbage
disposal”
• Destroy old
cells/organelles; “suicide
sacs”
http://library.thinkquest.org/12413/structures.html
Lysosomes
• Tay-Sachs disease occurs when the
lysosome is missing the enzyme needed
to digest a lipid found in nerve cells.
– As a result the lipid accumulates and nerve
cells are damaged as the lysosome swells
with undigested lipid.
Centriole
• Aids in cell division
• Only in animal cells
Vacuoles
• Large central vacuole
in plant cells
• Many smaller
vacuoles in animal
cells
• “Storage container”
for water, food,
wastes, etc.
Plant Cell Features
• Unique Features of Plant Cells
– Plant cells have three structures that animal
cells lack:
• a cell wall
• Chloroplasts
• Large vacuole
Chloroplast
• Found in plant cells
• Capture energy from
the sunlight and
convert it into
chemical
energy…PHOTOSY
NTHESIS!
• Green in color because
of chlorophyll, a green
pigment
http://library.thinkquest.org/12413/structures.html
Cell Wall
• Found in plant and
bacterial cells
• Rigid, protective
barrier that provides
support
• Located outside of the
cell membrane
• Made of cellulose
(fiber)
Quick Review
• Which organelle is the control center of the cell?
Nucleus
• Which organelle holds the cell together?
Cell membrane
• Which organelles are not found in animal cells?
Cell wall, chloroplasts
• Which organelle helps plant cells make food?
Chloroplasts
• What does E.R. stand for?
Endoplasmic reticulum
Elodea Cells
http://carnegieinstitution.org/first_light_case/horn/lessons/images/chlorop.jpg
Cheek Cells Stained with Methyl Blue
Plasma
Membrane
Nucleus
Cytoplasm
http://faculty.kutztown.edu/friehauf/science_outreach/cheek_cells_005.jpg