-
What are the major inorganic ions required for bacterial growth?
- Phosphate
- Sulfate
- Potassium
- Magnesium
-
What are the trace elements required for bacterial growth?
- Iron
- Cobalt
- Zinc
- Molybdenum (Mo)
- Manganese
- Copper
-
What are psychrophiles?
- Bacteria with a temperature range of -15-20° C
- Optimum growth at 10-15° C
-
What are mesophiles?
- Bacteria with a temperature range of 20-40°C
- Optimum growth at 30-40°C
-
What are thermophiles?
- Bacteria with a temperature range of 45-122°C
- Optimum growth at 50-80°C
-
Explain oxidation and reduction in terms of NAD
 - OIL RIG – oxidation is loss reduction is gain
-
List the classification for each tube
- Aerotolerant = 1
- Obligate anaerobe = 2
- Facultative anaerobe = 3
- Microaerophile = 4
- Obligate aerobe = 5
-
What causes dental carries?
- Lactic acid produced during fermentation by Streptococcus mutans
- Rare example of normal bacterial flora causing disease
-
What causes gas gangrene?
Clostridia (eg Clostridium Perfringens) generate H2 gas during fermentation that can be felt under the skin of a patient with gas gangrene
-
Which side of the cell are Hydrogen ions concentrated on during bacterial aerobic respiration?
The outside of the cell
-
How does the ATP motor work? Be sure to include a unit, c-ring, and gamma unit
- Protons from outside the cell enter a unit and bind to c-ring subunit
- C ring and gamma unit turns and projects proton internally
- Rotation forces gamma unit to center of the hexamer which allows the energy of rotation to be trapped in phosphate bonds producing ATP
-
How many hydrogens are required to drive a bacterial flagella motor one revolution?
256
-
What type of flagellar motor does Vibrio cholerae use?
They use a sodium driven flagella outside a host, but during an infection they swap to a hydrogen driven flagella
-
What are the types of bacteria classified according to oxygen consumption?
- Obligate anaerobe
- Aerotolerant
- Microaerophile
- Facultative anaerobe
- Obligate Aerobe
-
What are the catalase positive organisms?
- • Staphylococci (important not confuse it with streptococci)
- • Pseudomonas aeroginosa
- • Aspergillus fumigatus
- • Candida
- • Enterobacteriaceae (specially Klebsiella and Serratia both of which can cause pneumonia and UTI)
-
Which group(s) of bacteria lack enzymes such as catalase for detoxifying oxygen radicals?
- Obligate anaerobes
- This is why they cannot tolerate an oxygen-rich environment, because the free radicals cannot be dealt with
-
Do streptococci have catalase? What classification are they based on O2 consumption?
They are aerotolerant and they lack catalase
-
Do staphylococci have catalase? What classification are they based on O2 consumption?
They are facultative anaerobes and they have catalase as well as superoxide dismutase and peroxidase
-
How do bacteria divide?
- FtsZ is a tubulin-like protein that assembles as a ring of filaments (the Z-ring) at mid-cell
- MinCDE proteins ensure that the Z-ring forms at mid-cell.
- MinCD prevents FtsZ from forming at the poles, and MinE prevents MinCD from forming at mid-cell
- Z-ring constricts and forms a septum and then divides the cell
- *Mutations in Min proteins allow Z-ring to form at an inappropriate site
-
How is Proline used in bacteria?
organic osmolyte used in maintaining osmotic balance and salt tolerance in bacteria
-
What are the three strategies bacteria use to acquire iron?
- Siderophore systems: iron binding complexes secreted by bacteria which bind iron and are then taken up by the bacteria
- Transferrin and Lactoferrin: some bacteria can make receptors for these directly
- Heme acquisition: surface receptors that can strip Heme, once internalized iron is released also some release hemophores that act like siderophores but target heme instead of just iron
-
What three components are required to transport substances to the exterior of a gram negative cell?
ABC transporter, membrane fusion protein, Outer Membrane (OM) factor
-
What are the type III secretion systems used for?
- They are similar in structure to bacterial flagella/ATPase
- Needle-like and can puncture host cells and inject proteins
-
What is planktonic growth?
Life as a free living cell, floating or swimming in a liquid
-
What is Biofilm growth?
Life in a community, attached to a surface, encased in a matrix
-
What are the three staged of biofilm growth?
- Attachment
- Matrix development
- Dispersion (seeding other biofilms, can lead to chronic or secondary infections)
-
Biofilms commonly infect prosthetic joints, what are the two main organisms responsible for more than 90% of prosthetic joint infection?
Staphylococcus aureus and Staphylococcus epidermidis
|
|
