Schein Flashcards
WHat is a bacterial cytoskeleton made up of
mreB and parB
- actin homologues required for chromosome/plasmid segregation
Where are the complexes of the respiratory chain found in bacteria?
In the plasma membrane
- equivalent to the mitochondrial inner membrane.
Comments of the. Envelope f gram-positive bacteria
- thick peptidoglycan
- fibrillae - adhere to mammalian cells and ECM
- teichoic acids
- group carbohydrate
Envelopes of gram-negative bacteria
- both inner and outer plasma membrane with cell wall in the middle.
- space between inner and outer membrane is termed peri plasm
- lipopolysacharide (LPS)
WHat is LPS?
In gram negative cells, they are a component of the outer membrane. It is made up of:
- Lipid A - endotoxins that is part o the cell wall
- core
- O-antigen - repeat of 3-5 sugars
Porin proteins
Allow solute so to traverse outer membrane
- trimer
- exterior covered with hydrophobic AAs
- interior lined with hydrophilic AAs
Lipid A
Part of the LPS
- it is an endotoxins so if you kill the bacteria with antibiotic it can result in endotoxins release and other inflammatory components. Can cause fever and hypotension called the Jarish-Herxheimer reaction
- LPS binding to TLRs leads to synthesis and release of inflammatory cytokines, which locally causes defense but systemically can cause shock, organ dysfunction, and death.
What are the bacterial appendages and what do they. Do?
Flagella - locomotion
Pili/fimbrae - adhesion
Conjugation pilli - transfer of DNA between cells
What species of bacteria make spores?
Gram + rods
Which way of flagella rotation cause which movement?
Counter-clockwise - smooth swimming
Clockwise - random tumbling
Chemotaxis
Bacteria swim up concentration gradient towards attractant and they tumble down concentration gradient
