3. Microbiome and Biology of Bacteria Flashcards
A 72 old man is in the ICU for an bacterial infection. Several area of the body are tested to localize the infection. Which of the following areas would be the least concerning for the physicians to find microorganisms?
A. Bone B. Peritoneal Fluid C. Blood D. Stomach E. CSF
RFA
Ans. D Stomach
All the other areas are normally free of microorganisms while the Stomach has a large normal bacterial population
A lab worker is doing test and notices that in a patients sample the ration of Bacteroidetes to Firmicutes has shifted. Which condition is this characteristic of?
A. IBD colitis
B. Psoriasis
C. Childhood asthma
D. Obesity
RFA
Ans D. Obesity- shift in ratio of Bacteroidetes to Firmicutes
A. IBD colitis- increase in Enterobacteriaceae
B. Psoriasis- shift in ratio of Firmicutes to Actinobacteria
C. Childhood Asthma- absence of gastric H. pylori.
Hair mostly contains this gram positive bacteria with a high GC group:
A. Firmicutes B. Proteobacteria C. Bacteroidetes D. Cyanobacteria E. Actinobacteria
SZ
Ans. E Actinobacteria makes up approx 60% of bacteria in hair. It is a gram positive bacteria from soil and water. It has a high GC group.
Which of the following an essential macroelement for growth of bacteria?
A. Zinc B. Copper C. Potassium D. Nickel E. Lipids
SZ
Ans. C. Potassium
is essential for bacterial enzymes and protein synthesis
The GI tract is home to a plethora of different bacterial species, from aerobic to anaerobic . Helicobacter Pylori is a gram negative bacterium that is able to survive within the environment of the upper GI tract particularly due to which of the following enzymes?
A. Peroxidase B. Coagulase C. Superoxide Disimutase D. Lactate dehydrogenase E. Catalase
FA
C. H. Pylori is considered to be an a Microaerophil and thus only has the Superoxidase Dismutase enzyme allowing it to resist oxygen concentrations of up to 10%.
maybe a bit of an unfair question due to him not having putting examples of microaerophiles on the slides, but H. Pylori is probably the only microaerophiles that is relevant to us.
Anaerobic respiration is the mechanism of that many bacteria utilize to create ATP in the absence of Oxygen. Which of the following molecules is an example of an electron accepter from this process.
A. Ethanol B. Carbon Dioxide C. Oxygen D. Phosphate E. Pyruvate
FA
B. Carbon Dioxide, along with Nitrite(NO3) and Sulfate(SO4) are the principle electron acceptors for Anaerobic Respiration
Which of the following is not one of the main factors that influences the stationary phase? (MG)
A. pH
B. Temperature
C. Accumulation of waste
D. O2
B. Temperature
Temperature is the main influence of the log/exponential phase. All others influence the stationary and death phases.
You isolate a microbe and observe that it can grow in the presence and absence of O2. What is the oxygen requirement and which of the following enzymes is most likely to have?
A) Obligate Aerobe, S.O.D.
B) Microaerophile, Catalase
C) Facultative Aerobe, Peroxidase
D) Obligate Anaerobe, S.O.D.
Correct any mismatches in answer choices as extra practice
MM
Answer- C because this can grown in the absence of O2 it will have fermentation enzyme Peroxidase and most likely S.O.D. as well since it is capable of living in O2
A - S.O.D. and Catalase
B - NO, they have S.O.D. only
D - NO, they can’t live in O2 so they wouldn’t have S.O.D. they would use the fermentation enzyme peroxidase
You isolate a microbe and observe that is an anaerobic microbe. Which of the following is the BEST final electron acceptor?
A) O2 B) NO3- C) SO4- D) CO2 E) Pyruvic Acid
MM
Answer - B
Aerobic Final Acceptor - O2
Anaerobic - 1. NO3- 2. SO4- 3. CO2
Fermentation - Pyruvic Acid
Plasmids have genes for all except which of the following? (MG)
A. Antibiotic resistance
B. Toxins
C. Host cell death
D. Transfer
C. Host cell death
Plasmids do not kill the host cell they are incorporated into like viruses do.
Take away from this question is that plasmids code for antibiotic resistance, toxins, and transfer.
