MCB 3020 Exam 2 Study Guide
Questions with Latest Update
What is the most common mechanism for bacterial cell division? - Answer-Binary fission
List the 4 steps of Binary Fission - Answer-1. Elongation of cell
2. Replication of chromosome
3. Separation of chromosomes into 2 parts of cell
4. Formation of septum in middle
Define 'Origin of Replication' - Answer-Where replication begins
How many origins of replication do bacterial chromosomes have? - Answer-1
What is cytokinesis? Include brief overview of its four steps. - Answer-Division of a cell
into two via a formation of a septum in the middle of cell
Penicillin-Binding Protein - Answer-Group of proteins that hydrolyze bonds in existing
peptidoglycan strands and link together new strands
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) - Answer-Major
components of peptidoglycan that bind to a membrane protein called bactoprenol
Autolysins - Answer-Degrade polypeptide where new units are to be added, and the
new NAM-NAG units can then be inserted into peptidoglycan layer
What is crescentin? - Answer-A homologue or eukaryotic intermediate filaments
What are the other forms of asexual reproduction? Define each - Answer-- Budding:
budding off daughter cells; seen in Listeria monocytogenes
- Baeocyte formation: multiple rounds of cell division; seen in Cyanobacteria
- Spore formation: form multinucleoid filaments that ultimately divide to produce spores
with a single nucleus
Bacterial Growth Curve - Answer-- Lag phase: no net growth because; although the
nutrients are abundant, the bacteria are adjusting to new conditions
- Log (exponential) phase: nutrients are abundant, and bacteria divide at their highest
rate
- Stationary phase: number of viable microorganisms is stable because the nutrients
level off and waste products accumulate
, - Death phase: nutrients are depleted, and levels of waste products and toxins are high,
so number of viable microorganisms decreases
- Long-term stationary phase: nutrients are depleted, and waves of genetic variants
come and go; natural selection
T/F: When nutrient levels are low, limitation of microbial growth occurs as a result of
saturation of transport proteins for nutrient uptake - Answer-False; should when levels
are high
What is the generation time (GT)? - Answer-Time it takes the population to double
What phase is it best to calculate GT? - Answer-Log phase
T/F: Cells typically exist in aqueous conditions - Answer-True
Define hypertonic and hypotonic. - Answer-- Hypertonic: one solution has higher
concentration of solutes than another
- Hypotonic: One solution has lower concentration of solutes than another
If a cell is in a hypertonic solution it will ______, while in a hypotonic solution it will
_______ - Answer-Shrink, burst
What are the 3 distinct cardinal growth temperatures for organisms? - Answer--
Minimum: lowest temp at which an org can grow and survive
- Maximum: highest temp at which an org can grow and survive
- Optimal: most suitable temp for bacterial growth
Halophiles - Answer-Grow best in extremely salty environments
Xerophiles - Answer-Grow best in dry conditions
Psychrophiles - Answer-Grow between 0 C and 20 C - refrigeration temperatures
Mesophiles - Answer-Grow between 20 C and 45 C; most human pathogens
Thermophiles - Answer-Grow between 55 C and 85 C
Hyperthermophiles - Answer-Grow between 85 C and 113 C - usually Archaeans
Aerobe - Answer-Grow in presence of atmospheric oxygen
Questions with Latest Update
What is the most common mechanism for bacterial cell division? - Answer-Binary fission
List the 4 steps of Binary Fission - Answer-1. Elongation of cell
2. Replication of chromosome
3. Separation of chromosomes into 2 parts of cell
4. Formation of septum in middle
Define 'Origin of Replication' - Answer-Where replication begins
How many origins of replication do bacterial chromosomes have? - Answer-1
What is cytokinesis? Include brief overview of its four steps. - Answer-Division of a cell
into two via a formation of a septum in the middle of cell
Penicillin-Binding Protein - Answer-Group of proteins that hydrolyze bonds in existing
peptidoglycan strands and link together new strands
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) - Answer-Major
components of peptidoglycan that bind to a membrane protein called bactoprenol
Autolysins - Answer-Degrade polypeptide where new units are to be added, and the
new NAM-NAG units can then be inserted into peptidoglycan layer
What is crescentin? - Answer-A homologue or eukaryotic intermediate filaments
What are the other forms of asexual reproduction? Define each - Answer-- Budding:
budding off daughter cells; seen in Listeria monocytogenes
- Baeocyte formation: multiple rounds of cell division; seen in Cyanobacteria
- Spore formation: form multinucleoid filaments that ultimately divide to produce spores
with a single nucleus
Bacterial Growth Curve - Answer-- Lag phase: no net growth because; although the
nutrients are abundant, the bacteria are adjusting to new conditions
- Log (exponential) phase: nutrients are abundant, and bacteria divide at their highest
rate
- Stationary phase: number of viable microorganisms is stable because the nutrients
level off and waste products accumulate
, - Death phase: nutrients are depleted, and levels of waste products and toxins are high,
so number of viable microorganisms decreases
- Long-term stationary phase: nutrients are depleted, and waves of genetic variants
come and go; natural selection
T/F: When nutrient levels are low, limitation of microbial growth occurs as a result of
saturation of transport proteins for nutrient uptake - Answer-False; should when levels
are high
What is the generation time (GT)? - Answer-Time it takes the population to double
What phase is it best to calculate GT? - Answer-Log phase
T/F: Cells typically exist in aqueous conditions - Answer-True
Define hypertonic and hypotonic. - Answer-- Hypertonic: one solution has higher
concentration of solutes than another
- Hypotonic: One solution has lower concentration of solutes than another
If a cell is in a hypertonic solution it will ______, while in a hypotonic solution it will
_______ - Answer-Shrink, burst
What are the 3 distinct cardinal growth temperatures for organisms? - Answer--
Minimum: lowest temp at which an org can grow and survive
- Maximum: highest temp at which an org can grow and survive
- Optimal: most suitable temp for bacterial growth
Halophiles - Answer-Grow best in extremely salty environments
Xerophiles - Answer-Grow best in dry conditions
Psychrophiles - Answer-Grow between 0 C and 20 C - refrigeration temperatures
Mesophiles - Answer-Grow between 20 C and 45 C; most human pathogens
Thermophiles - Answer-Grow between 55 C and 85 C
Hyperthermophiles - Answer-Grow between 85 C and 113 C - usually Archaeans
Aerobe - Answer-Grow in presence of atmospheric oxygen
