Bacterial Growth
Exponential growth phase
a period of maximum growth
Division of bacterial cells occurs mainly through __________ ____________
binary fission
During the stationary phase, growth cease may be due to
both balance or ceasing to divide
Stationary phase may result from a balance between _________ ___________ and _______________ _______________
cell division and cell death
microbial growth occurs with increase in __________
cell population
microbial growth occurs with growth at a ___________ level with increase in ________
cellular, size
during binary fission the parent cell forms a ___________ ____________ ___________(crosswall) dividing the cell into _______ __________ ____________ __________
central transverse septum, two identical daughter cells
▪The pop is uniform in terms of _____________ and ________________ properties
chemical and physiological
during binary fission the parent cell duplicates its _____________ or ___________
chromosome, copies DNA
when a bacterial cell divides into two cells each cell receives a _______________
complete chromsome
During glycolysis rxns occur in the __________________ of _________ and __________ cells
cytoplasm, prok, euk
during the cell cycle It is believed that the chromosome attaches to the ______________ _____________ and is separated as the _______ and __________ continue to ____________ and ___________ cell components. The __________ continues to grow.
cytoplasmic membrane, CW and CM, enlarge and separate, cell envelope
during the cell cycle The ____________ also helps in the process of separating components into 2 new __________ _____________
cytoskeleton, daughter cells
Stationary phase may be cause by _________ in nutrients, _________ in space & ___________ pH (toxic accumulation of ____&_______)
decrease, increase, decrease (acid and waste)
Stationary phase may also result from the population may simply cease to _____________ though remaining metabolically active - but at a much _____________ rate
divide, reduced
Exponential growth causes the population to ___________ with each division
double
Death phase is due to detrimental (toxic/deadly) _____________ changes
env
Cells may be old and depleted: of ______, _____, and/or nutrients (any and/or all of these factors) which are needed to _____________ & _____________
enzymes, ribosomes, metabolize, grow
Death phase: Die off __________________ / ________________
exponentially/logarithmically
When microbes are introduced into __________ medium usually no ___________ increase in cell numbers
fresh, immediate
Time required for a complete fission cycle is called the _______time
generation
when organisms divide is a regular, genetically determined interval called the _________________
generation time
When a bacterial cell divides into two cells and an additional portion of the _________ whose synthesis was _________ part way through the ________ cycle.
genome, initiated, fission
Most of the time the bacteria are
getting ready for division
Eventually growth ceases and the curve becomes ___________ (usually around ________ bacteria/ml_).
horizintal, _10^9
Later in the infection phase the __________ __________ kills the invader (_______ phase)
immune response, death
cells are _____________ in size
increasing
Growth patterns in microorgs also account for stages in an ___________
infection
Death phase -_____________ factors intensify
limiting
Generation time is always determined during
log phase
In log phase, Bacteria are growing and dividing at the _______________/ optimum rate possible
max rate
Different sugar→different ____________ pathway→different _______(s)
metabolic, enzymes
usually ________ infectious during the log phase= so usually more infectious ___________ of the infection
more, at the beginning of
The shorter the generation time the more easily a pathogen can ____________ quickly= thus the pathogens large numbers initially ___________ the immune system
multiply, overwhelm
cells are making ____________ components
necessary
If environmental factors are not optimum then a Decrease in ____________&_____________ and an increase in ___________ & ____________ = ______ growth rate
nutrients and O2, acids and waste, decreased
Exponential growth phase continues as long as cells have __________ are present and _____________ are good
nutrients and env conditions
In a closed system where ___________ and ________ are finite (limited) and the growth period over a few hours to few days produces a curve consisting of a ________ phase, __________ phase, ______________ phase, and __________ phase
nutrients and space, lag, log, stationary, death
loss of ______________ (____________ used up) and ________________ is now toxic (toxic waste & acids)
nutrients, nutrients, low pH
during glycolysis rxns occur with or without ___________
oxygen
during binary fission the ____________ cell enlarges
parents
during the cell cycle, the cell must _________ the DNA and cytoplasmic components by synthesizing a ____________.
partition, cytoplasmic, septum or crosswall
Bacteria do not maintain their __________ growth rate because in most systems it is influenced by ___________ factors- ____________ because bacteria in flasks or test tubes with just some media have _______ conditions
potential, env, esp in lab, limiting
Instead a population typically displays a ________________ pattern or ___________ over time.
predictable pattern or growth curve
the organisms divide at their most ____________ rate
rapid
Why do Industry/ Medicine/ Research use bacteria in log phase when most uniform?
reliable/comparible results
Leaving food at ________ temp even for a short period means that a ________ can grow to large #s in a _______ time
room, bacteria, short
during the cell cycle, the _______ is initiated by invaginations of the cell envelope layers ______ or ______
septum, invaginations, envelope, CM, CW
Each new fission cycle increases the population by a factor of ______
two
Microbial growth occurs at _______ levels
two
decline in the number of __________ cells characteristic of the death phase
viable
In stationary phase the total number of _______________ remains constant
viable microorgs
Actively growing cells are more __________ to conditions that disrupt ______________ and __________________
vulnerable, binary fission, cell metabolism
Mycobacterium leprae (leprosy) has a very _______ cell wall due to presence of _________ ________
waxy, mycolic acid
Vibrio sp. generation times
10 minutes
during the cell cycle At least ______ in E. coli are responsible for the occurrence of __________
12 proteins, septation
Mycobacterium leprae has a generation time of
14 days
However E. coli can reproduce every _____ minutes
20
E. Coli generation time
20 minutes
E. Coli can reproduce every _______ minutes because New _____ synthesis is initiated ________ a previous round of DNA synthesis is __________.
20, DNA, before, completed
Bacteria average generation time is ~___-___ minutes under _______ conditions.
20-60, optimum
DNA replication in E. coli takes ____minutes to completely copy the bacterial chromosome
40
Nf=(Ni)2^n
Formula used to predict number of cells that arise during a time period
Microorgs in the log phase of growth are more: ____ /______ / metabolically active/ rapidly growing (______ rate) /robust compared those in the death phase.
INSERT, INSERT, max
____________/______________/____________ use bacteria in log phase when most uniform
Industry /Medicine / Research