7.1 The Discovery of Cells
•
Cell Theory
1. All organisms are
composed of one or more
cells.
2. The cell is the basic unit of
organisms.
3. All cells come from
preexisting cells.
content.answers.com/.../ 300px-Hooke's_cork.png
7.1 The Discovery of Cells
• All cells come from
one cell…they just
keep dividing
• All cells contain all the
genetic info. or DNA
• Some cells have
special functions and
use only a small part
of the DNA
www.csa.com/.../stemcell/images/pluri.jpg
7.1 The Discovery of Cells
Types of Cells
– Prokaryotic
• No membrane bound
organelles
• No nucleus
• Most unicellular
organisms
ww.phschool.com/.../ images/cells/allcell.jpg
7.1 The Discovery of Cells
– Eukaryotic
• Membrane bound
organelles
• Nucleus
• Most multicellular (except
ameobas, yeast and
some algae)
• Much larger (see pg 174)
Animal vs. Plant Cell
Note the
differences!
CELLS
Prokaryotic
Eukaryotic
Animal cell
Plant Cell
Cell Wall
• Found in plant
cells
• Located outside
the Plasma
membrane
• Function:
protection and
support
• Made of
cellulose
7.2 The Plasma Membrane
• Plasma Membrane:
– Flexible boundary between cells &
environment
– Selectively permeable: ___
– Phospholipid Bilayer
– Cholesterol, Protein
www.biology.arizona.edu/.../ graphics/bilayer.giff
fig.cox.miami.edu/.../ 150/memb/fluidmosaic.jpg
nai.arc.nasa.gov/team/ images/2006/ciw/1829/1.jpg
7.2 The Plasma Membrane
• Fluid Mosaic Model
fig.cox.miami.edu/.../ 150/memb/fluidmosaic.jpg
http://www.bio.davidson.edu/people/macampbell/111/memb-swf/membranes.swf
fig.cox.miami.edu/.../ 150/memb/fluidmosaic.jpg
7.2 The Plasma Membrane
academic.brooklyn.cuny.edu/biology/bio4fv/pag...
Nucleus
• Manages and controls all cell functions
• Holds genetic information
• Nucleolus is found there
– Makes ribosomes
www.palaeos.com/.../Lists/Images/nucleolus.jpg
iweb.tntech.edu/mcaprio/normalonionskin.jpg