Transcript Prokaryotic Cells

Prokaryotic Cells
Eukaryotic Cells
And Virus
Notes Gallery
Prokaryotic vs. Eukaryotic Notes
Know these Greek word parts
Pro – before
Prokaryotic cells existed before
eukaryotic cells.
Eu – true
A Eukaryotic cell has a true nucleus.
Karyote – kernal or nut
Referring to the nucleus
Prokaryotic Cells
• One-celled organisms:
Bacteria
• No organelles
• Few internal structures
• Unicellular or colonial
• Cell Wall
• Cell Membrane
• Circular Chromosomes
• No nuclear membrane
Example
Prokaryotic Cells
Microbes live in the water we drink, the
food we eat, and the air we breathe. Right
now, billions of microbes are swimming in
our digestive systems and crawling on our
skin! But don't worry, over 95% of
microbes are harmless. Microbes are
single-cell organisms invisible to the eye
that come in different shapes seen only
with microscopes.
Prokaryotic Cells
Shapes of Prokaryotes
Draw these
three shapes in
your booklet and
label them.
Prokaryotic Cells
Example of spherical shaped Bacteria
Group A Streptococcus is a bacterium
often found in the throat and on
the skin. People may carry group A
streptococci in the throat or on the
skin and have no symptoms of
illness. Most GAS infections are
relatively mild illnesses such as
"strep throat," or impetigo.
Occasionally these bacteria can
cause severe and even lifethreatening diseases.
Prokaryotic Cells
Example of rod shaped Bacteria
Escherichia coli (E. coli) bacteria
normally live in the intestines
of healthy people and
animals. Most varieties of E.
coli are harmless or cause
relatively brief diarrhea. But a
few particularly nasty strains,
such as E. coli O157:H7, can
cause severe abdominal
cramps, bloody diarrhea and
vomiting.
Prokaryotic Cells
Example of spiral shaped Bacteria
Treponema pallidum: The
cause of syphilis, this is a
microscopic bacterial
organism called a
spirochete, a worm-like
spiral-shaped organism
that wiggles vigorously
when viewed under a
microscope.
Eukaryotic
• Contain organelles
surrounded by membranes
• Contain a nucleus
• Unicellular or multicellular
• Cell Wall (plants and fungi)
• Cell Membrane (all)
• Most living organisms
• Linear Chromosomes
Prokaryotic vs.
Eukaryotic Notes
Eukaryotic Cell division
Due to their increased numbers of chromosomes, organelles and
complexity, eukaryote cell division is more complicated, although the
same processes of replication, segregation, and cytokinesis still
occur.
Eukaryotic cells form identical daughter cells by replicating and
dividing the original chromosomes. This process, called Mitosis, is
like making cellular xerox copies. Commonly the two processes of
cell division are confused. Mitosis deals only with the segregation of
the chromosomes and organelles into daughter cells.
Prokaryotic vs.
Eukaryotic Notes
Prokaryotic Cell division
The usual method of prokaryote cell division is termed binary
fission. The chromosome is a single DNA molecule first replicate,
then attach each copy to a different part of the cell membrane. When
the cell begins to pull apart, the replicated and original chromosomes
are separated. Following cell splitting (cytokinesis), there are then two
cells of identical genetic composition (except for the rare chance of a
spontaneous mutation).
One consequence of this asexual method of reproduction is that all
organisms in a colony are genetic equals. When treating a bacterial
disease, a drug that kills one bacteria (of a specific type) will also kill all
other members of that clone (colony) it comes in contact with.
Prokaryotic vs. Eukaryotic Notes
Comparing The Size
White blood cell ttacking
bacterial cells.
This is a picture of bacteria (the
short, plump, curved rods)
associated with a eukaryotic cell
(upper right). The line on the
bottom left represents 1
micrometer. Note the size
comparison.
um means micrometers
Prokaryotes: 0.2 to 2.0 um
smaller than eukaryotes (less
complicated; fewer structures)
Eukaryotes: 10 – 100 um
larger and more compex
more internal structures.
Viruses vs. Cells