Exam 3 Review Materials ACTUAL UPDATED QUESTIONS AND CORRECT
ANSWERS
, steps of binary fission 1. cell elongates
2. chromosome replicates
3. DNA separates between 2 cells
4. septum cross-wall forms
5. cells separates
Fts Z protein assemble the Z ring that anchors to the plasma membrane.
Z ring protein fibers on the inside of a prokaryotic cell membrane in the middle of the
cell that tightens, causing cytokinesis
How long does E.coli replication take? - 40 minutes of DNA replication
- 20 minutes if separation and cytokinesis
Bacterial growth curve Lag phase: metabolic activity w/o division Log phase: rapid cell division Stationary
phase: nutrient depletion slows growth. Spore formation in some bacteria. Death
phase: prolonged nutrient depletion and buildup of waste products leads to
death.
Where was the bacterial growth curve established? - artificial
- lab only
- culture based, batched in culture closed system
Lag phase 1. Microbes are new to the fresh media
2. nor increase in the number of microbes
3. cells are old and need to get used to the new environment conditions
- deprived of ATP
- length depends on media, type of microbe, etc
Log phase - exponential growth
- rate depends of the environment and species
- where antibiotics are most effective
Stationary phase - no cell growth- closed system, cells are growning and dying at the same rate
- nutrients are low and waste is high (causes pH change)
- cells are competing and stressed
- critical level of the population
Actinomycets bacteria -group of bacteria that produce 2/3 of all antibiotics
- antibiotics produce during the syayionary phase
death phase - decrease in the number of cells
- loss of viability
- VBNC- viable but not culturable
Macronutrients needed for growth - C, H, O , N, S, P
- K, Ca, Mg, Fe
ANSWERS
, steps of binary fission 1. cell elongates
2. chromosome replicates
3. DNA separates between 2 cells
4. septum cross-wall forms
5. cells separates
Fts Z protein assemble the Z ring that anchors to the plasma membrane.
Z ring protein fibers on the inside of a prokaryotic cell membrane in the middle of the
cell that tightens, causing cytokinesis
How long does E.coli replication take? - 40 minutes of DNA replication
- 20 minutes if separation and cytokinesis
Bacterial growth curve Lag phase: metabolic activity w/o division Log phase: rapid cell division Stationary
phase: nutrient depletion slows growth. Spore formation in some bacteria. Death
phase: prolonged nutrient depletion and buildup of waste products leads to
death.
Where was the bacterial growth curve established? - artificial
- lab only
- culture based, batched in culture closed system
Lag phase 1. Microbes are new to the fresh media
2. nor increase in the number of microbes
3. cells are old and need to get used to the new environment conditions
- deprived of ATP
- length depends on media, type of microbe, etc
Log phase - exponential growth
- rate depends of the environment and species
- where antibiotics are most effective
Stationary phase - no cell growth- closed system, cells are growning and dying at the same rate
- nutrients are low and waste is high (causes pH change)
- cells are competing and stressed
- critical level of the population
Actinomycets bacteria -group of bacteria that produce 2/3 of all antibiotics
- antibiotics produce during the syayionary phase
death phase - decrease in the number of cells
- loss of viability
- VBNC- viable but not culturable
Macronutrients needed for growth - C, H, O , N, S, P
- K, Ca, Mg, Fe
