Bacterial Metabolism Pathways
Could use some MicoBiologly Help?
Answer all that you feel you can…
For the following bacterial parts, give the structure (what is it composed of) and the function (what does it do).
1. pili
2. capsule
3. cell wall
4. cell membrane
5. What are the pathways used for aerobic metabolism of glucose.
6. What are the pathways used for anaerobic metabolism of glucose.
7. What molecules transport electrons to the electron transport pathway.
8. What is the purpose of fermentative metabolism.
Pili: Small proteinaceous appendages found on bacteria
used for conjugation (exchange of genetic material
between bacterial cells, “sex” between bacteria) A
special type of pilus, called Fimbriae, is used by bacteria
to attach to surfaces
Capsule: Mucopolyssacharide (carbohydrate) layer residing
outside the cell wall in SOME but not all bacterial
cells, predominant in pathogenic organisms.
Cell Wall: Made of peptidoglycans which are polymers of
N-acetylneuraminic acid alternating with N-acetyl-
glucosamine linked to penta-glycine bridges
Their main role is that they protect the bacteria from
Lysis in hypotonic environment, also help maintain
cell shape and role in binary fission.
1. Protection from phagocytes (white blood cells)
2. Protection from viruses
3. Protection from dessication (drying out of
Bacteria)
4. Prevents entry of toxic substances into cell
Cell Membrane: Phospholipid bilayer along with proteins and
carbohydrates outside the cytoplasm that
function in transport and communication. It
is also involved in ATP production.
5. Anaerobs produce energy by 2 ways:
1. Fermentation
C6H12O6 + 2 ADP + 2 phosphate → 2 lactic acid +
2 ATP by lactic acid fermentation
C6H12O6 + 2 ADP + 2 phosphate → 2 C2H5OH + 2
CO2 + 2 ATP
6. Anerobic respiration:
If the electron acceptor in the transport chain in the
bacterial cell wall is anything other then oxygen ie.
internally-generated electron acceptor, usually pyruvate.
The transport chain generates the proton-motive force
used in ATP production much like in cellular respiration.
7. These are reducing equivalents or electron donors which
can be organic, ie. NADH or even inorganic hydrogen or
sulfide
8. Fermentation allows the cell to regenerate reducing
equivalents and continue to make ATP, by coupling it to the
oxidation of a small molecule such as pyruvate and
producing lactate, ethanol, hydrogen, butyrate, etc. in the
process and allows to cell continue to produce ATP
anaerobically. Please note that the end-products are NOT
fully oxidized and still contain chemical potential energy,
consequently much less ATP is produced as a result.
Metabolism – part 2
Metabolism Masterclass