Chapter 4
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Bacteria divide by binary fission—what does this mean? Are the daughter cells identical
to the parent cell?
Biofilms are sticky layers of bacteria that can grow on surfaces. Can you think of surfaces
where this would be a problem? Why might bacteria form a biofilm?
When growing bacteria in the lab, what is the difference between an open and closed
culture? Can you give an example of an open and closed culturing method?
Understand the terminology of growth curves (such as exponential phase, etc). What are
primary and secondary metabolites?
What is generation time? Why might generation time be important when growing
bacteria in the lab? During infection?
Bacteria have different conditions they can live and thrive in (optimal). We work mostly
with meso- and neutrophiles. You should be familiar with these terms (at least able to
match the term with what it means).
This chapter also touches on the oxygen requirements of different types of bacteria.
Where do obligate aerobes grow (like M. luteus)? How about a facultative anaerobe (like
E. coli)? Obligate anaerobe? How do aerobic bacteria detoxify the by-products of
respiration (superoxide dismutase and catalase).
Bacteria need nitrogen to survive and grow. What are two sources of nitrogen for
bacteria?
Phosphorous and iron are usually limiting elements in the environment, but run-off (from
fertilizer) can contain phosphorous and create environments suitable for toxic blue-green
bacterial blooms.
Bacteria need both energy and carbon to survive. Energy can come from sunlight,
inorganic chemicals and organic compounds. What energy source does a phototroph use?
A chemotroph?
Carbon can either be taken out of the air (CO2) or come from organic compounds. Where
does a heterotroph get its carbon? An autotroph?
Growth factors are organic compounds (like amino acids and vitamins) that some bacteria
need to grow. Why is it important to know about growth factors when growing bacteria in
the lab? E. coli doesn’t need any growth factors—it can synthesize everything it needs
from a carbon and energy source (glucose) and salts (that contain the other necessary
elements).
What is complex media? What is chemically defined media? What is the function of agar
and why is it ideal for making plates?
Selective media inhibits the growth of some bacteria, differential media changes in an
observable way when certain bacteria grow on it. How can we use selective media to help
enrich a mixed culture for a certain bacteria? What is pure culture? What is a streak
plate?
We can measure microbial growth either directly or by viable cell counts. What are the
different methods and what are the advantages/disadvantages of these methods?
Chapter 6
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What do bacteria “eat” (what is their carbon source)?
What is ATP?
aerobic bacteria (use oxygen as a terminal electron acceptor, uses an electron transport
system)
anaerobic bacteria (use something that is not oxygen as an electron acceptor, still use an
electron transport system)
fermentors (use pyruvate or a pyruvate derivative as an electron acceptor, no electron
transport system)
What is the purpose of glycolysis?
What happens to the pyruvate and the NADH produced during glycolysis in fermenting
organisms?
What happens to the pyruvate in respiring aerobic organisms? What is the transition step?
What is the TCA cycle and what does it produce?
What are electron carriers and how do they relate to the electron transport chain?
What happens to the energy level of electrons as they go down the transport chain? What
is this energy used for? Why are hydrogen pumps important and what does ATP synthase
produce?
Photosynthesis uses light (photons) to split water, generating electrons (which are carried
by electron carriers to the chloroplast/cell membrane) and oxygen as a by-product (this is
why plants make oxygen). What does the cell use these electrons for (photosystem II)?
After this, instead of the electrons then being put into a terminal electron acceptor (like
oxygen for aerobic respirators), it gets re-powered by more photons and then can either
be used to power the proton pump or to create NADPH (which is used to fix carbon).
What does the Calvin cycle do? Is it energy-creating or energy-using?
Does all glucose that enters glycolysis become reducing power and CO2 by the end of the
TCA cycle?
What do enzymes do? Are they used up in a reaction?
What is the active site? What binds to the active site?
What kinds of factors can influence enzymatic activity?