Download Cell Structure & Function

Cell Structure
& Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
History of the Cell
• Around 1665, Robert
Hooke observed a
piece of cork and saw
tiny cavities.
• This was the first time
cells were observed.
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Robert Hooke’s Microscope
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Magnified Cork
Felix Dujardin
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• Mid - 1800,
Frenchman Felix
Dujardin discovered
protoplasm.
• This is the living
material inside the
cell.
Robert Brown
• Mid-1800
• Found the nucleus.
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Theodore Schwann
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• While observing plant
and animal cells, he
noted that plant cells
have a cell wall while
animal cells do not.
M J Schleiden
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• Was comparing plant
and animal cells at
the same time as
Schwann.
• Found similar ideas.
Together, Schleiden and Schwann
formulated the Cell Theory.
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. (It was once believed
that living organisms could come from
non-living organisms Spontaneous
Generation.)
Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.
Examples of Cells
Human Cell
Plant Stem
Nerve Cell
Red Blood 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
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 ribosomes
& 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
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
Plant Cell vs Animal Cell
Plant and Animal Cells are very similar in
structure with the exception of the following
organelles:
Plant Cells Have:
Animal Cells Have:
cell wall
centrosomes
chloroplast