MMG 301 Exam 3 Questions with Correct Answers Latest Update 2025/2026
Transpeptidase, the enzyme that cross-links peptidoglycan in bacterial cell walls - Answers β-
lactam target
Weakens cell wall → lysis due to osmotic pressure - Answers Effect of β-lactams on bacteria
β-lactam ring - Answers Structure defining all β-lactams
Enzyme that cleaves β-lactam rings → antibiotic inactivation - Answers NDM-1 function
Enzymatic degradation of antibiotic - Answers Resistance mechanism of NDM-1
Encodes PBP2a, a transpeptidase that does not bind β-lactams - Answers MecA function
High MIC value - Answers How to identify resistance on an E-test
Low MIC value - Answers How to identify sensitivity on an E-test
Measures DNA amount in real time through amplification - Answers qPCR purpose
Growth-independent, does not require live bacteria - Answers qPCR dependency
Low starting DNA amount - Answers High CT value meaning
Number of microbes that kill 50% of hosts - Answers LD50 definition
Number of microbes that infect 50% of hosts - Answers ID50 definition
More virulence → lower LD50 - Answers Effect of virulence on LD50
More virulence → lower ID50 - Answers Effect of virulence on ID50
Breaks down collagen to aid tissue invasion - Answers Collagenase function
Compares bacterial DNA by separating large fragments - Answers PFGE purpose
Determines if isolates are the same strain - Answers PFGE in outbreaks
Ingest bacteria → they grow in the body - Answers Food infection
Ingest pre-formed toxin - Answers Food poisoning
Nutrient deprivation or extreme stress - Answers Trigger for sporulation
Stabilize spore DNA - Answers SASPs function
Provides heat resistance to spores - Answers Dipicolinic acid role
Molecule recognized by immune system - Answers Antigen definition
Transpeptidase, the enzyme that cross-links peptidoglycan in bacterial cell walls - Answers β-
lactam target
Weakens cell wall → lysis due to osmotic pressure - Answers Effect of β-lactams on bacteria
β-lactam ring - Answers Structure defining all β-lactams
Enzyme that cleaves β-lactam rings → antibiotic inactivation - Answers NDM-1 function
Enzymatic degradation of antibiotic - Answers Resistance mechanism of NDM-1
Encodes PBP2a, a transpeptidase that does not bind β-lactams - Answers MecA function
High MIC value - Answers How to identify resistance on an E-test
Low MIC value - Answers How to identify sensitivity on an E-test
Measures DNA amount in real time through amplification - Answers qPCR purpose
Growth-independent, does not require live bacteria - Answers qPCR dependency
Low starting DNA amount - Answers High CT value meaning
Number of microbes that kill 50% of hosts - Answers LD50 definition
Number of microbes that infect 50% of hosts - Answers ID50 definition
More virulence → lower LD50 - Answers Effect of virulence on LD50
More virulence → lower ID50 - Answers Effect of virulence on ID50
Breaks down collagen to aid tissue invasion - Answers Collagenase function
Compares bacterial DNA by separating large fragments - Answers PFGE purpose
Determines if isolates are the same strain - Answers PFGE in outbreaks
Ingest bacteria → they grow in the body - Answers Food infection
Ingest pre-formed toxin - Answers Food poisoning
Nutrient deprivation or extreme stress - Answers Trigger for sporulation
Stabilize spore DNA - Answers SASPs function
Provides heat resistance to spores - Answers Dipicolinic acid role
Molecule recognized by immune system - Answers Antigen definition
