Lecture 3: Bacterial Metabolism and Growth Flashcards
What are four features that make bacterial metabolism unlike human?
1) Faster
2) More diverse energy sources
3) Simplicity in macromolecules
4) Has LPS, toxins, peptidoglycan
___: acquire carbon from organic sources; ___ fix CO2 as a primary means of acquiring carbon
A. Heterotrophs; Autotrops
B. Autotrops; Heterotrophs
A. Heterotrophs; Autotrops
Most pathogenic bacteria are ____
heterotrophs
What are the two types of autotrophs?
1) Photoautotrophs: harvest light energy
2) Chemoautotrophs: cellular energy comes from oxidation/reduction of inorganic ions
True or False: Fastidious heterotrophs have MORE complex growth requirements and tend to be SLOWER growing while non-fastidious heterotrophs tend to have LESS complex
True
___ is an an example of a non-fastidious bacteria while ___ is an example of a fastidious bacteria
Mycoplasma (fastidious)
E. Coli (non-fastidious)
Low levels of Fe++ can induce _____ ____ to produce toxin
Corynebacterium diptheriae
True or False: Low or high levels of ions can serve as signals for pathogen
True
True or False: Most pathogens are thermophils
False - most pathogens are mesophiles (growth between 20-55 C)
___ display growth > 55 degrees C
while ___ display growth at < 20 degrees C
Thermophile; Cryophile/Psychrophile
Bacteria must be able to protect themselves from deleterious effects of oxygen (O2) or otherwise will only grow ____
anaerobically
True or False: Vibrio cholerae and V. parahaemolyticus are halophiles
True (meaning they have a special ionic requirement)
True or False: Refrigeration is NOT an acceptable method of maintaining or obtaining sterile conditions
True
Why are aerobes and facultative anaerobes able to grow in the presence of O2?
Because they make enzymes that detoxify superoxide radicals (O2-) and H2O2
Note: both superoxide radicals and H2O2 are made in the presence of O2 during cellular metabolism
Which enzyme detoxifies O2?
Which enzyme detoxifies H2O2?
Superoxide Dismutase: detoxifies O2-
Catalase: detoxifies H2O2
Which two enzymes are present in aerobes and facultative anaerobes, but NOT in obligate anaerobes?
Catalase and Superoxide Dismutase
Which of the following is an obligate aerobe (meaning: requires O2 and metabolizes via respiration)?
A. Mycobacterium tuberculosis
B. Campylobacter jejuni
C. Facultative anaerobes
A. Mycobacterium tuberculosis
True or False: Facultative anaerobes (most pathogens) grow well with or without oxygen
True
Campylobacter jejuni is an example of:
A. Obligate Aerobes
B. Microaerophiles
C. Facultative Anerobe
B. Microaerophiles
Aerotolerant anaerobes cannot use ____, but will tolerate it while Obligate anaerobes are inhibited or killed by any ____
oxygen
Lactobacillus is an ____ while Clostridium and Bacteroides are _____
A. Aerotolerant; Obligate Anaerobes
B. Obligate Anaerobes; Aerotolerant
A. Aerotolerant; Obligate Anaerobes
Special requirements are needed to collect specimens and culture ___ from specimens
A. Aerotolerant anaerobes
B. Facultative anaerobes
C. Anaerobes
C. Anaerobes
True or False: Lactobacillus produce lactic acid, making it an acidophile, while Bacillus is an alkaliphile
True
True or False: Most human pathogens are neutrophiles
True
Respiration and Fermentation generate __ and ___
ATP and NAD+
What is the function of respiration?
Provide energy via: Proton Motive Force for ATP synthesis (production) during the conversion (recycling) of NADH2 to NAD
Why is respiration a unique enzymatic process?
Because most of the process must occur in a membrane vesicle or sack !!