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Lecture 5 - Microbiology - Chapter 7 Brock
Biology Exam Questions With Correct
Answers
Which Min protein guides the FtsZ ring to the center and is located at the center? -
answer✔MinE
Define antimicrobial agent - answer✔any agent, natural or synthetic, that has the ability to
suppress or kill microorganisms
-cidal agents ______ microorganisms - answer✔kill
-static inhibits ________ in microorgansims - answer✔growth
-lytic agents completely _______ the cell - answer✔lyse
Bacteriostatic agents inhibit biochemical processes such as protein synthesis and bind _____.
Hence, when the agent is added, the viable cell count becomes ______ for a time, and when
removed the viable cell count _______ again. The total cell count ______ the viable cell count. -
answer✔weakly, static, increases, equals
Bacteriocidal agents bind tightly and _____ the cell. This means the viable cell count will
________ towards zero, whilst the total cell count ______ ______. - answer✔kill, decrease,
doesn't change
Bacteriolytic agents kill by _______. This means viable cell count _________ towards zero as
cells are dying, and also total cell count ___________ towards zero as cells are ______. -
answer✔lysis, decreases, decreases, bursting
Define Minimum Inhibitory Concentration (MIC)? - answer✔smallest concentration of drug that
visibly inhibits growth
Describe disc diffusion assay method used to compare efficacy of antibiotics for example: -
answer✔Uses solid media. Antimicrobial agent added to filter paper disc. MIC is reached at
some distance.
, ©SIRJOEL EXAM SOLUTIONS
10/3/2024 9:54 PM
Define zone of inhibition - answer✔on an agar plate the area of non growth surrounding a paper
disc containing an antimicriobial substance.
Define sterilant - answer✔Agent that destroys all microorganisms, including bacterial spores
Define disinfectant - answer✔Used on surfaces to kill all microorganisms, but not necessarily
endospores. Toxic to humans
Define sanitizers - answer✔reduce microbial numbers but do not sterilize
Define antiseptic - answer✔chemical that kills microorganisms in the environment and safe for
the skin
Define super-resolution microscopy - answer✔light microscopy using fluorescent molecules,
observes dynamic behaviours in real time, high res
photoactivated localization microscopy - answer✔
What protein regulates chromosome replication initiation in microbes? - answer✔DnaA
DnA binding to specific sequences within the o_______ r_______ leads to D___ u________ and
loading of r______. This is most active when linked to A___ (DnaA-ATP). - answer✔oriC
region, DNA unwinding, replisome, ATP
After initiation, DnaA-ATP needs to be inactivated to prevent another replisome binding for
organisation purposes. The molecular mechanism for this involves c_________ for oriC
b_______; r__________ of dnaA e_________; t_________of DnaA-ATP away from o____;
i__________ of D__________. - answer✔competition, binding, repression, experession,
titration, oriC, inactivation, DnaA-ATP
dnaA is a _____ - answer✔gene
DnaA is a ______ - answer✔protein
Before replication initiation, what happens to both DNA strands? - answer✔They're methylated
After replication initiation, which DNA strand is still methylated and what is this concept called?
- answer✔only the parental strand; hemimethylated DNA
What is the function of SeqA? - answer✔Strongly binds to hemimethylated OriC which blocks
DnaA-ATP expression
What is the oriC locus? - answer✔origin of replication