Microbial Growth Flashcards
____________ and product formation are exquisite complex processes that represent the overall
kinetics and stoichiometry of the thousands of __________ reactions that can be observed
within a cell.
Microbial growth , intracellular
It involves consumption of substrates which provide energy and raw
materials required for the __________ of additional cell mass.
Microbial growth, synthesis
defined as some fixed amount of cell material
System
The __________ as nutrients must be compatible with the available __________ of the cell for __________.
compounds supplied , enzymatic
machinery , catabolism and biosynthesis
obeys the laws of conservation of mass.
Microbial / Cell Growth
free energy of products formed must be ________ the free energy of substrate consumed
less than
this process requires that the cell environment contains elements needed to form additional cell mass
Microbial / Cell Growth (macroscopic view)
the free energy of substrates consumed should exceed the free energy of cells and metabolic products’ formed.
Microbial / Cell Growth (macroscopic view)
some fixed amount of cell material
System
The whole point of the macroscopic perspective is that certain ________ apply to this growth process independent of the particular
___________ which the “system” of cells employs to affect the overall
growth reaction
stoichiometric constraints , mechanism or reaction pathways
resolve the question of chemical suitability of certain nutrients by simply restricting our attention to
nutrients which are known to be acceptable substrates for growth of the cell strain of interest.
if cell growth were to continue according to the overall “reaction”, which substrate would be exhausted first.
- Stoichiometrically Limiting Compou
may be identified for a particular strain and environment (temperature, pH, and background of certain other nutrients) in the following operational way
Growth-Rate Limiting Medium Component
If the concentration of a particular medium component is increased suddenly, does the growth rate of the cells increase?
effect (medium component concentration –> growth rate of cell)
rearranged in the metabolic processes of the cell
Atoms of carbon, nitrogen, hydrogen, oxygen, and the other elements of life
total amounts of each of arbon, nitrogen, hydrogen, oxygen, and the other elements of life incorporated into cell material is ________________ from the environment.
equal to the amounts removed (total amt of elements into cell material = amts removed from the environment)
the amount of some metabolic product formed or the amount of heat released by cell growth is often __________to the amount of consumption of some substrate or the amount of __________
proportional, formation of another product such as CO2.
2 examinations
material balance (rigorous), empirical stoichiometric relationship (approximate)
stoichiometric considerations have broad implications in biochemical technology such as (ranging from)
o growth medium formulation to
o computer control and
o cooling requirements in bioreactors.
in reactor analysis in general, knowledge of stoichiometric relationships is critical in
o formulating bioreactor material balances and
o making most effective and systematic use of reaction kinetics.
Although the cell is ________, the ________________ of substrates into products and cellular materials is often represented by a ____________for it also obeys the law of conservation of mass.
complex, stoichiometry of conversion, simple pseudo-chemical equation
objectives
- how these equations can be written
- how useful estimates of key yield coefficients can be made.
____________ is founded upon the fundamental principle known as the ______________________________
Stoichiometry, Law of Conservation of Mass
____________ asserts that within an ___________, mass cannot be created nor destroyed; rather, it can only change forms or be transformed.
Law of Conservation of Mass or (Stoichiometry) , isolated system
In line with ______________ law, it is imperative that the total mass of the reactants remains ________the total mass of the products in the context of a low-energy thermodynamic process.
Law of Conservation of Mass, equal to
In biological reactions, the application of a _____________ becomes straightforward if we have_________________________________________
material balance,
o compositions of substrates
o products, and
o cellular materials.
in the realm of biochemical reactions, the determination of _________ often necessitates not only elemental balances but also _____________
stoichiometric coefficients, electron-proton balances
accurately establishing the quantitative relationships between the various components
elemental balances
electron-proton balances
All atoms of carbon, hydrogen, oxygen, nitrogen, and other elements consumed during growth incorporated into _____________________________________
new cells or excreted as products.
Once the identity of the substrate (carbon source) is known, ___________ and contains no unknown variables.
CwHxOyNz is fully specified
chemical ‘formula’ for dry cells.
CHαOβNδ
Escherichia coli Stoichiometric Equation Composition of Cells
C - 50
O - 20
N - 14
H - 8
P - 3
S -1
K -1
Na -1
Ca - 0.5
Mg - 0.5
Cl - 0.5
Fe - 0.2
Others - 0.3
__________ of the biomass can be accounted for by four major elements ___________________________
90 to 95%, C, H, O, and N
________ tend to have slightly higher _______ contents (11-14%) than _________ (6.39-9.0%).
Bacteria, nitrogen, fungi
