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Microbiology Test #1 Review Questions
Spring, 2013
Definitions:
1. Be able to define and give a prokaryotic example/function of the following
terms:
a. Uniport
b. Antiport
c. Symport
d. Simple transport
e. Group translocation
f. ABC transporter
g. Periplasmic binding proteins
h. Gram positive
i. Gram negative
j. Type III secretion system
k. Endotoxin
l. Techoic acid
m. Porins
n. Lipopolysaccharide
o. S-layers
p. Capsules
q. Slime layers
r. Fimbriae
s. Pili (give 4 functions)
t. Horizontal gene transfer
u. Carbon storage polymers
v. Magnetosomes
w. SASPs
x. Flagellin
y. Peritrichous
z. Lophotrichous
aa. Polar
bb. Phototaxis
cc. Chemotaxis
dd. Aerotaxis
ee. Osmotaxis
ff. Binary fission
gg. Divisome
hh. Crescentin
ii. Bactoprenol
jj. Penicillin binding proteins
kk. Compatible solutes
ll. Proton motive force
mm.
Sodium motive force
nn. Cardinal temparatures
Microorganisms and Microbiology:
1. Be able to discuss the properties that all cells share, and those that only some
cells have. Why do viruses not quite fit the definition of life?
2. Be able to give examples of a variety of environments in which microbes live,
and to discuss how living in communities can provide evolutionary
advantages to microbes.
3. What is LUCA, and when did it arise?
4. Be able to discuss major events in the evolution of microbial life, in
particular:
a. The most probable metabolic strategies of the earliest microbes
b. The origin of eukaryotes
c. The origin of an ‘oxic’ earth
5. Be able to discuss the major accomplishments of scientists involved in the
discovery of microorganisms, in particular:
a. Robert Hooke
b. Antoni van Leuwenhoek
c. Ferdinand Cohn
d. Louis Pasteur
e. Robert Koch
6. What are Koch’s postulates, and why are they problematic for many of
today’s diseases?
A Brief Journey to the Microbial World:
1. Be able to discuss how bright light microscopes work. Recognize the parts in
a diagram, and tell what each does.
2. Be able to define and discuss magnification and resolution.
3. How does wavelength affect resolution?
4. Why is immersion oil necessary for many high-power objective lenses?
5. What does ‘parfocalized’ mean, and how is it related to magnification and
focal length?
6. What is numerical aperature, and how is it related to resolution?
7. Be able to discuss several ways to visualize unpigmented cells. Which work
for living cells?
8. Be able to briefly discuss how phase-contrast, darkfield, fluorescence,
confocal laser-scanning, DIC, atomic force and electron microscopy work.
Which ones generate 3-D images? Which ones can work on living cells?
9. How were the three domains of life discovered? What does the evidence tell
us about the relationships between Bacteria, Archaea and Eukarya? Which of
these domains is the most diverse?
10. Be able to discuss the basic metabolic groups that can be differentiated based
on energy source (chemical vs. light, organic vs. inorganic) and carbon
source. Be able to tell these sources based on name…for example “give the
energy and carbon source of a photoautotroph… chemoorganoheterotroph…
etc.
Cell Structure and Function in Bacteria and Archaea
2. Be able to define/draw the major prokaryotic cell morphologies
3. Be able to differentiate between Bacteria, Archaea and Eukarya with regard
to the following:
a. Average size/average metabolic rate (what does the size of
prokaryotes tell us about their ability to exchange nutrients, grow and
evolve?)
b. Structure of the cytoplasmic membrane
c. Types and functions of membrane proteins present
d. Structure/location of genetic material
e. Presence/absence of organelles and ribosomes
f. Flagellar structure (Bacteria and Archaea only)
4. Be able to describe/draw/label the major components of Gram positive and
Gram negative cell walls and to tell how they are involved in the differential
nature of Gram staining.
5. Be able to recognize (not draw) and tell the biological significance of the
following prokaryotic molecules:
a. Diaminopimelic acid
b. D-alanine (no…you wont’ have to differentiate between it and Lalanine)
c. NAM/NAG dimer
d. Isoprene
e. Diglycerol tetraethers
f. Ribitol
g. O-specific polysaccharide
h. Dipicolinic acid
i. Glycerol (give 3 different biological roles from the lectures/book)
6. Gram negative bacteria have unique transport problems, given the structure
of their cell wall. Give two ways that they overcome these problems.
7. Describe the periplasm.
8. Discuss 2 chemical ways in which Archaeal and Bacterial cell walls can differ.
What is the biological significance of these differences?
9. What are gas vesicles? What is their biological purpose, and what is their
molecular structure?
10. Be able to discuss endospores in detail, including:
a. Sporulation cycle
b. Structure of the endospore, including structural and chemical
differences when compared to vegetative cells
c. Why microbes make endospores
d. The implications of endospores for ‘sterilization’
11. Be able to draw/describe the structure of a gram negative flagellum.
12. How to Fli and Mot proteins work to determine whether a flagellum will
rotate?
13. How does the proton-motive force generate energy for flagellar rotation?
14. Be able to describe the relationship between prokaryotic motion, (forward,
tumbling and reverse) and the direction of flagellar rotation (CCW or CW)
in bacteria with peritrichous flagella. How does this differ in bacteria with
reversible and unidirectional polar flagella?
15. Describe how microbes use their flagella for microbial taxes.
16. Be able to describe the three mechanisms that underlie gliding motility.
Microbial Growth
1. Describe how cell growth occurs in a Gram negative rod such as E. coli. Be
sure to discuss the roles of all Fts proteins (Z, I, A, K), ZipA , Min C, D and E.
2. Describe how the peptidoglycan layer expands to accommodate increases in
cell size in Gram positive vs. Gram negative bacteria.
3. How do MreB proteins control cell morphology in Gram negative bacteria
such as E. coli?
4. How does penicillin kill bacteria by impacting cell wall synthesis?
5. Be able to describe the lag, exponential, stationary and death phases in batch
cultures. Tell how you would modify the amount of time that cells spend in
the lag phase and the exponential phase.
6. Be able to describe what a chemostat is.
7. How does dilution rate impact cell growth in a chemostat?
8. How does nutrient concentration impact cell growth in a chemostat?
9. Be familiar with the cardinal temperatures of mesophiles, thermophiles,
hyperthermophiles and psychrophiles.
10. What types (Domains) of microorganisms can be psychrophiles?
Thermophiles? Hyperthermophiles?
11. Be able to compare and contrast the mechanisms that psychrophiles use to
adapt to cold temperatures (proteins, lipids, nucleic acids, cell walls, cellular
products) with those that thermophiles and hyperthermophiles use.
12. What are some of the environmental challenges faced by acidophiles, and
how do they overcome them? Alkaliphiles? Halophiles?
13. Be able to describe the oxygen requirements and types of metabolism used
by obligate and facultative aerobes, microaerophiles, aerotolerant anaerobes
and obligate anaerobes.
14. Why is living an aerobic life so risky (from an oxidation standpoint), and how
do aerobic microbes deal with these challenges? What unique challenge does
a microaerophile have in this regard, and how do they deal with it?