MGY377 Exam Questions and Verified
Answers
Question 1
What is the main form of gene formation in prokaryotic evolution? -
Correct Answer
Horizontal gene transfer
Question 2
What is acquired resistance?
Correct Answer
> Alteration of target (genetic mutation)
> Efflux (protein pump production)
> Alteration/inactivation of drugs (production of b-lactamse, methylase, acetylase,
phophotransferase/kinase, adenylyltransferase)
Question 3
What caused banded iron formation? -
Correct Answer
Precipitated ferric that is deposited in rocks
> stromatolites through iron oxide trapping
Page 1 of 583
,Question 4
What are the steps to how the Bacteroides sp. use TBDT and surface/periplasmic
enzymes to take in large sugars?
Correct Answer
1. SusG is a glycoside hydrolase alpha-amylase that breaks down starch into
oligosaccharides
2. SusC/D/G/E/F complex brings in malto-oligosaccharides through SusC (attached
to TonB in IM w/ SusR)
3. SusA/B (neopullulanse/alpha-glucosidase) in perplasm break down oligos into
monomers which transport through a monosaccharide importer
Question 5
What happens when PG is disrupted?
Correct Answer
The PG sack is retained and keeps the shape of bacteria
Question 6
What is the great oxygenation event? -
Correct Answer
After most elements absorbed O2, there was no where left to go meaning that it
went into the atmosphere killing off tons of anaerobes
Question 7
Are Salmonella SPI's more AT or GC-rich? -
Correct Answer
AT-rich
Page 2 of 583
,Question 8
How does reversible insertion and excision occur on lambda phage?
Correct Answer
1. attP (phage) integrates with attB (bacterial) via integrase
> 15 bp sequences
> integrase makes scattered cuts and strand transfer into prophage after looping
2. Integrase takes prophage out and loops then Xis will excise this loop into
separate genomes
> repressors are all phage proteins
> IHF is also needed in bacteria (idk for what?)
Question 9
What does periplasmic binding protein do?
Correct Answer
Shuttles substrate to IM (to ABC transporter)
Question 10
How are bile acids modified by gut microbes?
Correct Answer
They convert them to secondary bile acids (like by Chlostridium scindens)
> Cholic acid -> Deoxycholic acid (very toxic)
> Taurocholic acid -> Cholic acid + Taurine
Question 11
What type of AI-1 does LuxR bind?
Correct Answer
Species-specific
Question 12
What is zoonotic infection?
Correct Answer
Animal to human transmission
Page 3 of 583
, Question 13
What are two types of artificially-induced competence?
Correct Answer
1. Calcium-induced (~10% competent)
> E.coli treated with high [Ca] stored in cold and transformable at low efficiency
> dsDNA/plasmids w/ no DUS
2. B. Electroporation (~95% competent)
> pulsed electric field -> small transient pores
> DNA outside can enter pores
> requires lots of technical work
> most species (ss/dsDNA)
Question 14
What happened in the late 1970s/early 1980s with biofilms and medical devices?
Correct Answer
It was found that bad biofilms would grow on medical devices and served as a
reservoir for repeated infections as they were tolerant to antibiotics
Question 15
What do phages control?
Correct Answer
Most control central dogma, REs
Question 16
What is the structure of Lipid A?
Correct Answer
> Forms outer leaflet of OM
> Hydrophobic, looking different from
phospholipids
> Always saturated straight fatty acids
> Phosphorylated N-acetylglucosamine dimer
with 4-7 fa's atttached
> Attached to KDO (2-keto-3-deoxyoctonic
acid), -ve charge
Page 4 of 583
Answers
Question 1
What is the main form of gene formation in prokaryotic evolution? -
Correct Answer
Horizontal gene transfer
Question 2
What is acquired resistance?
Correct Answer
> Alteration of target (genetic mutation)
> Efflux (protein pump production)
> Alteration/inactivation of drugs (production of b-lactamse, methylase, acetylase,
phophotransferase/kinase, adenylyltransferase)
Question 3
What caused banded iron formation? -
Correct Answer
Precipitated ferric that is deposited in rocks
> stromatolites through iron oxide trapping
Page 1 of 583
,Question 4
What are the steps to how the Bacteroides sp. use TBDT and surface/periplasmic
enzymes to take in large sugars?
Correct Answer
1. SusG is a glycoside hydrolase alpha-amylase that breaks down starch into
oligosaccharides
2. SusC/D/G/E/F complex brings in malto-oligosaccharides through SusC (attached
to TonB in IM w/ SusR)
3. SusA/B (neopullulanse/alpha-glucosidase) in perplasm break down oligos into
monomers which transport through a monosaccharide importer
Question 5
What happens when PG is disrupted?
Correct Answer
The PG sack is retained and keeps the shape of bacteria
Question 6
What is the great oxygenation event? -
Correct Answer
After most elements absorbed O2, there was no where left to go meaning that it
went into the atmosphere killing off tons of anaerobes
Question 7
Are Salmonella SPI's more AT or GC-rich? -
Correct Answer
AT-rich
Page 2 of 583
,Question 8
How does reversible insertion and excision occur on lambda phage?
Correct Answer
1. attP (phage) integrates with attB (bacterial) via integrase
> 15 bp sequences
> integrase makes scattered cuts and strand transfer into prophage after looping
2. Integrase takes prophage out and loops then Xis will excise this loop into
separate genomes
> repressors are all phage proteins
> IHF is also needed in bacteria (idk for what?)
Question 9
What does periplasmic binding protein do?
Correct Answer
Shuttles substrate to IM (to ABC transporter)
Question 10
How are bile acids modified by gut microbes?
Correct Answer
They convert them to secondary bile acids (like by Chlostridium scindens)
> Cholic acid -> Deoxycholic acid (very toxic)
> Taurocholic acid -> Cholic acid + Taurine
Question 11
What type of AI-1 does LuxR bind?
Correct Answer
Species-specific
Question 12
What is zoonotic infection?
Correct Answer
Animal to human transmission
Page 3 of 583
, Question 13
What are two types of artificially-induced competence?
Correct Answer
1. Calcium-induced (~10% competent)
> E.coli treated with high [Ca] stored in cold and transformable at low efficiency
> dsDNA/plasmids w/ no DUS
2. B. Electroporation (~95% competent)
> pulsed electric field -> small transient pores
> DNA outside can enter pores
> requires lots of technical work
> most species (ss/dsDNA)
Question 14
What happened in the late 1970s/early 1980s with biofilms and medical devices?
Correct Answer
It was found that bad biofilms would grow on medical devices and served as a
reservoir for repeated infections as they were tolerant to antibiotics
Question 15
What do phages control?
Correct Answer
Most control central dogma, REs
Question 16
What is the structure of Lipid A?
Correct Answer
> Forms outer leaflet of OM
> Hydrophobic, looking different from
phospholipids
> Always saturated straight fatty acids
> Phosphorylated N-acetylglucosamine dimer
with 4-7 fa's atttached
> Attached to KDO (2-keto-3-deoxyoctonic
acid), -ve charge
Page 4 of 583
