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Microbio-Exam 2 Verified and Updated
Questions and Answers (100% Correct
Answers)
What are the two building blocks (two sugars) of peptidoglycan and what type of
linkages does it have?
Answer: N-Acetlyglucosamine (G) and N-acetylmuramic acid (M), linked by glyosidic
linkage
Describe protoplasts. How can they be formed?
Answer: They are the cell but without the cell wall, self containing. Can be found
naturally or can be made through cell lysis
Compare and contrast the cell walls of Bacteria and Archaea.
Answer: Bacteria: ester linkages in phospholipids, fatty acids compose hydrophobic
part of membrane
Archaea: ether linkages in phospholipids, not fatty acids (no carboxylic acid) but
polymers of isoprene (phytanyl) as hydrophobic portion of molecule
Name and describe the three functions of the cytoplasmic membrane.
Answer: Permeability barrier: prevents leakage and functions as a gateway for
transport of nutrients into and out of the cell
Protein anchor: site of many proteins involved in transport, bioenergetics, and
chemotaxis
Energy conservation: site of generation and use of proton motive force
What are the three types of simple transporters and how do they work?
Answer: Simple transport: driven by the energy in the proton motive force
Uniporter: one kind of molecule in one direction
Antiporter: two different molecules going two different ways
Symporter: transports two different molecules together, either in or out
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What is group translocation?
Answer: Chemical modification of the transported substance driven by
phosphoenolpyruvate
What is the ABC transport system?
Answer: Periplasmic binding proteins are involved and energy comes from ATP
Where do each of the membrane transport systems discussed in class get their
energy?
Answer: Simple transport: proton motive force
Group transport: becomes phosphorylated, uses energy provided by high energy
bond
ABC: ATP binding cassette
Which transport system is best for transport of nutrients in extremely low
concentrations?
Answer: ABC Transporters
How can proteins be exported from the cell?
Answer: Translocases: secretion of macromolecules, insertion into the cytoplasmic
membrane
-important when enzymatic functions are needed outside of the cell
What is a periplasm? What types of bacteria have a periplasm?
Answer: Periplasm: "concentrated gel-like matrix in the space between the inner
cytoplasmic membrane and the bacterial outer membrane"
-found in gram negative bacteria
What are porins and what is their function? Where are they found?
Answer: -allow for permeability across the outer membrane
-create channels that cross the membrane
Name the two endospore forming bacteria genus that we discussed.
Answer: Bacillus and Clostridium
What are the different types of cell inclusions that we discussed in class? What are
they made of/what is their structure? What purpose do they serve for the cell?
Microbio-Exam 2 Verified and Updated
Questions and Answers (100% Correct
Answers)
What are the two building blocks (two sugars) of peptidoglycan and what type of
linkages does it have?
Answer: N-Acetlyglucosamine (G) and N-acetylmuramic acid (M), linked by glyosidic
linkage
Describe protoplasts. How can they be formed?
Answer: They are the cell but without the cell wall, self containing. Can be found
naturally or can be made through cell lysis
Compare and contrast the cell walls of Bacteria and Archaea.
Answer: Bacteria: ester linkages in phospholipids, fatty acids compose hydrophobic
part of membrane
Archaea: ether linkages in phospholipids, not fatty acids (no carboxylic acid) but
polymers of isoprene (phytanyl) as hydrophobic portion of molecule
Name and describe the three functions of the cytoplasmic membrane.
Answer: Permeability barrier: prevents leakage and functions as a gateway for
transport of nutrients into and out of the cell
Protein anchor: site of many proteins involved in transport, bioenergetics, and
chemotaxis
Energy conservation: site of generation and use of proton motive force
What are the three types of simple transporters and how do they work?
Answer: Simple transport: driven by the energy in the proton motive force
Uniporter: one kind of molecule in one direction
Antiporter: two different molecules going two different ways
Symporter: transports two different molecules together, either in or out
, Inquire through: | Professional | Confidential Support
What is group translocation?
Answer: Chemical modification of the transported substance driven by
phosphoenolpyruvate
What is the ABC transport system?
Answer: Periplasmic binding proteins are involved and energy comes from ATP
Where do each of the membrane transport systems discussed in class get their
energy?
Answer: Simple transport: proton motive force
Group transport: becomes phosphorylated, uses energy provided by high energy
bond
ABC: ATP binding cassette
Which transport system is best for transport of nutrients in extremely low
concentrations?
Answer: ABC Transporters
How can proteins be exported from the cell?
Answer: Translocases: secretion of macromolecules, insertion into the cytoplasmic
membrane
-important when enzymatic functions are needed outside of the cell
What is a periplasm? What types of bacteria have a periplasm?
Answer: Periplasm: "concentrated gel-like matrix in the space between the inner
cytoplasmic membrane and the bacterial outer membrane"
-found in gram negative bacteria
What are porins and what is their function? Where are they found?
Answer: -allow for permeability across the outer membrane
-create channels that cross the membrane
Name the two endospore forming bacteria genus that we discussed.
Answer: Bacillus and Clostridium
What are the different types of cell inclusions that we discussed in class? What are
they made of/what is their structure? What purpose do they serve for the cell?
