Hairy T-cell
Definition
= Three part theory about cells
1. All living things are made of cells.
Part 2 of the Theory
2. The cell is the basic structural and
functional unit of life.
Part 3 of the Theory
3. All cells come from pre-existing cells.
yeast cells dividing
Who came up with this theory?
1. Schleiden (circa 1838)
All plants are
made of cells!
Onion skin cells
Who came up with this theory?
2. Schwann
All animals are
made of cells!
Human red blood cells
Who came up with this theory?
3. Virchow
All cells
come from
pre-existing
cells!
How big are cells?
• Microscopic
(mostly)
• Measured in
microns µm
• (micrometers).
• A µm is one
millionth of a
meter =
• 10-9 m = one
thousandth of
1 mm.
How big are cells?
Smallest free-living cell =
Mycoplasma genitalium
Size = 0.2 to 0.3 µm
How big are cells?
• Bacteria e.g. Eschericia coli (aka E.coli)
• Size=1 µm by 3 µm
How big are cells?
• Human red blood cell = 8 µm in diameter
How big are cells?
• Largest cell on
the human
body =
ovum
• Size=
• 1000 µm in
diameter
(1 mm)
How big are cells?
• Smallest cell in the human body =
sperm cell.
How big are cells?
• Largest cell with a
metabolism =
Chaos chaos
Size=1-5 mm in
length.
common name =
Giant Amoeba
Chaos diffluens, is an amoeba closely related to the giant amoebae
How big are cells?
• Largest cell = yolk of an ostrich egg
Ostrich, egg, humans
Ostrich emerged from egg
How can we study cells?
Problem:
They are microscopic!
Solution:
Use a microscope!
Types of Microscopes
1. Compound light
microscope
– Light passes
through lenses to
magnify image up
to 1000X
– Can observe
living cells
Types of Microscopes
2. Electron
microscope
– Uses a beam of
electrons to
magnify image
> 1000X
– Kills cells being
observed
Common features of all cells
Small size – allows materials to move via
diffusion
• Diffusion = process by which
molecules move from levels of high
concentration to levels of low
concentration until equilibrium is
reached
Diffusion
• Google Image Result for
http://www.indiana.edu/~phys215/lecture/l
ecnotes/lecgraphics/diffusion.gif
Common features of all cells
1. Cell Membrane –
selectively/differentially
permeable (lets some things in
and out)
Common features of all cells
2. Cytoplasm – semi-fluid
material in which cell
organelles float
Common features of all cells
3. Nucleic
acid
containing genetic
code :
Which nucleic acid?
DNA
Common features of all cells
4. Cytoskeleton
– proteins that
support the cell
(Microtubules &
microfilaments)
Common features of all cells
5. Ribosomes
– make
proteins
If Cells could be really big ……
Star Trek - The Immunity Syndrome
Bibliography
•
•
•
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•
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http://www.hotlinecancer.com/?cat=28
http://news.bbc.co.uk/1/hi/sci/tech/4636121.stm
http://www.thebacteriabusters.com/eColi.html
http://www.lungcancer.co.uk/how.htm
http://www.fi.edu/learn/heart/blood/red.html
http://biology.about.com/library/weekly/aa091400a.htm
http://www.pbs.org/wgbh/amex/babies/peopleevents/e_ovum.html
http://www.dkimages.com/discover/Home/Animals/Birds/Growth-andDevelopment/Ostrich/Ostrich/Ostrich-15.html
http://www.flickr.com/photos/71751551@N00/1262329163/
http://commons.wikimedia.org/wiki/Image:Ostrich_egg.jpg
http://www.mambalam.net/slideshow.php?set_albumName=Animalia
http://strangebenevolent.blogspot.com/2007/07/meerkats-and-ostriches.html
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www.madsci.org/posts/archives/dec97/878139903.Cb.r.html
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http://en.wikipedia.org/wiki/Amoeba_proteus
http://en.wikipedia.org/wiki/The_Immunity_Syndrome_(Star_Trek
Bibliography
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http://www.pacpress.com/level3/micron.htm
Google Image Result for
http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion.gif
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http://commons.wikimedia.org/wiki/Image:Diffusion.jpg
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http://library.thinkquest.org/C004535/cell_membranes.html
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http://sun.menloschool.org/~cweaver/cells/e/ribosomes/
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http://www.elmhurst.edu/~chm/vchembook/580DNA.html
http://sciencecity.oupchina.com.hk/biology/student/glossary/cytoplasm.asp
http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect06.htm