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