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Most microorganisms pathogenic for humans grow best in the laboratory when cultures are incubated at

• 15–20°C

• 20–30°C

• 30–37°C

• 38–50°C

• 50–55°C

The process by which microorganisms form ATP during the fermentation of glucose is characterized by

• Coupling of ATP production with the transfer of electrons

• Denitrification

• The reduction of oxygen

• Substratephosphorylation

• Anaerobic respiration

The major effect of a temperature of 60oC on the growth of a mesophile such as Escherichia coli is to

• Destroy the cell wall

• Denature proteins

• Destroy nucleic acids

• Solubilize the cytoplasmic membrane

• Cause formation of endospores

Polymerization of building blocks (eg, amino acids) into macromolecules (eg, proteins) is achieved largely by

• Dehydration

• Reduction

• Oxidation

• Assimilation

• Hydrolysis

A strain of E coli does not require vitamins when grown in a defined medium consisting of glucose, mineral salts, and ammonium chloride. This is because E coli

• Does not use vitamins for growth

• Obtains vitamins from its human host

• Is a chemoheterotroph

• Can synthesize vitamins from the simple compounds pro-

  vided in the medium

• Ammonium chloride and mineral salts contain trace

  amounts of vitamins

Which of the following is NOT a mechanism for generating metabolic energy by microorganisms?

• Fermentation

• Protein synthesis

• Respiration

• Photosynthesis

• C and D

Which of the following terms best describes a microorganisms that grows at 20°C?

• Neutralophile

• Psychrotroph

• Mesophile

• Osmophile

• Thermophile

The ability to assimilate N2 reductively via NH3 is called

• Ammonification

• Anammox

• Assimilatory nitrate reduction

• Deamination

• Nitrogen fixation

Which of the following is NOT assimilated by eukaryotic cells?

• Glucose

• Lactate

• Sulfate (SO42-)

• Nitrogen(N2)

• Phosphate (PO43-)

Bacteria that are obligate intracellular pathogens of humans (eg, Chlamydia trachomatis) are considered to be

• Autotrophs

• Photosynthetic

• Chemolithotrophs

• Hyperthermophiles

• Heterotrophs