Organelles are distinct structures within cells that carry out specific functions. In prokaryotes, organelles are not surrounded by membranes, while in eukaryotes they are. Prokaryotic cells have a cell membrane, cell wall, cytoplasm, and genetic material stored in a nucleoid. They may also contain features like pili, flagella, and a mesosome for cellular respiration. Ribosomes in prokaryotic cells are found freely in the cytoplasm.

1. Organelles
 Definition: These are DISTINCT structures
within a cell that carry out a particular function
or set of functions.
 In PROKARYOTES: they are NOT surrounded
by a membrane
 In EUKARYOTES: they ARE surrounded by a
membrane

2. PROKARYOTIC CELLS
Common features:
o All have a CELL MEMBRANE and a CELL
WALL
•CELL MEMBRANE:
• A fluid system that controls
what comes in and what
goes out of the cell.
• It is semi-permeable.
•CELL WALL:
• A rigid structure that
protects the inner parts of
the cell from mechanical
damage.
• It is fully-permeable.

3. PROKARYOTIC CELLS
Common features:
o All have a CYTOPLASM
•CYTOPLASM
•It is the place where
chemical reactions (what
you know as metabolic
reactions) take place.
•Most of it (about 80%) is
water, therefore it looks like
“empty space” under the
microscope.

4. PROKARYOTIC CELLS
Common features:
o NONE have a NUCLEUS to carry genetic
information… • Genetic information:
A “handbook” of
instructions that will inform
the cell what to do: when
to grow, nourish,
reproduce, etc.
o ALL carry genetic information is stored in a loose
chromosome known as NUCELOID.

5. PROKARYOTIC CELLS
 ALL have a MESOSOME for cellular
respiration
The MESOSOME can
be seen as an
invagination of the
cell membrane. It is
made up of similar
stuctural components.

6. PROKARYOTIC CELLS
 ALL have a RIBOSOMES for making proteins
RIBOSOMES in
prokaryotic cells are
not attached to other
structures, but can be
found freely in the
cytoplasm.
They are seen as little
“dots” lying all over.

7. PROKARYOTIC CELLS
Common features:
o SOME have PILI…
PILI:
For attachment to
surfaces, usually of
other cells (allows
transfer of info)
FLAGELLA:
For propulsion and
movement.
o SOME have FLAGELLA

8. Representing cells in a diagram
Micrograph of E.coli Diagram of E.coli

9. References
 Bacterion. http://www.ucmp.berkeley.edu/bacteria/bacteriatem.gif Retrieved on Sept
20th, 2009.
 Capsules. http://bioinfo.bact.wisc.edu/themicrobialworld/capsule.jpg Retrieved on
Sept 20th, 2009.
 Cells Alive. http://www.cellsalive.com/cover2.htm Retrieved on Sept 20th, 2009.
 Cell membrane. http://www.chem.ox.ac.uk/vrchemistry/LivingCells/Pictures/ecoli.jpg
Retrieved Sept 20th, 2009.
 Ecoli diagram
http://www.mtmi.vu.lt/legacy/pfk/funkc_dariniai/nanostructures/images/0901whiteside
s_ecoli.jpg Retrieved Sept 20th, 2009.
 Ecoli micrograph. http://asymptotia.com/wp-images/2008/08/e_coli.jpg Retrieved on
Sept. 20th, 2009.
 Mesosome. http://www.biomedcentral.com/content/figures/1741-7007-7-22-2-l.jpg
Retrieved on Sept 20th, 2009.
 Nucleosome http://www.agen.ufl.edu/~chyn/age2062/lect/lect_06/5_44.GIF Sept
20th, 2009.