Microbial Growth

Question 1

____________ 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.

Answer 1

Microbial growth , intracellular

Question 2

It involves consumption of substrates which provide energy and raw
materials required for the __________ of additional cell mass.

Answer 2

Microbial growth, synthesis

Question 3

defined as some fixed amount of cell material

Answer 3

System

Question 4

The __________ as nutrients must be compatible with the available __________ of the cell for __________.

Answer 4

compounds supplied , enzymatic
machinery , catabolism and biosynthesis

Question 5

obeys the laws of conservation of mass.

Answer 5

Microbial / Cell Growth

Question 6

free energy of products formed must be ________ the free energy of substrate consumed

Answer 6

less than

Question 7

this process requires that the cell environment contains elements needed to form additional cell mass

Answer 7

Microbial / Cell Growth (macroscopic view)

Question 8

the free energy of substrates consumed should exceed the free energy of cells and metabolic products’ formed.

Answer 8

Microbial / Cell Growth (macroscopic view)

Question 9

some fixed amount of cell material

Answer 9

System

Question 10

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

Answer 10

stoichiometric constraints , mechanism or reaction pathways

Question 11

resolve the question of chemical suitability of certain nutrients by simply restricting our attention to

Answer 11

nutrients which are known to be acceptable substrates for growth of the cell strain of interest.

Question 12

if cell growth were to continue according to the overall “reaction”, which substrate would be exhausted first.

Answer 12

• Stoichiometrically Limiting Compou

Question 13

may be identified for a particular strain and environment (temperature, pH, and background of certain other nutrients) in the following operational way

Answer 13

Growth-Rate Limiting Medium Component

Question 14

If the concentration of a particular medium component is increased suddenly, does the growth rate of the cells increase?

Answer 14

effect (medium component concentration –> growth rate of cell)

Question 15

rearranged in the metabolic processes of the cell

Answer 15

Atoms of carbon, nitrogen, hydrogen, oxygen, and the other elements of life

Question 16

total amounts of each of arbon, nitrogen, hydrogen, oxygen, and the other elements of life incorporated into cell material is ________________ from the environment.

Answer 16

equal to the amounts removed (total amt of elements into cell material = amts removed from the environment)

Question 17

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 __________

Answer 17

proportional, formation of another product such as CO2.

Question 18

2 examinations

Answer 18

material balance (rigorous), empirical stoichiometric relationship (approximate)

Question 19

stoichiometric considerations have broad implications in biochemical technology such as (ranging from)

Answer 19

o growth medium formulation to
o computer control and
o cooling requirements in bioreactors.

Question 20

in reactor analysis in general, knowledge of stoichiometric relationships is critical in

Answer 20

o formulating bioreactor material balances and
o making most effective and systematic use of reaction kinetics.

Question 21

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.

Answer 21

complex, stoichiometry of conversion, simple pseudo-chemical equation

Question 22

objectives

Answer 22

• how these equations can be written
• how useful estimates of key yield coefficients can be made.

Question 23

____________ is founded upon the fundamental principle known as the ______________________________

Answer 23

Stoichiometry, Law of Conservation of Mass

Question 24

____________ asserts that within an ___________, mass cannot be created nor destroyed; rather, it can only change forms or be transformed.

Answer 24

Law of Conservation of Mass or (Stoichiometry) , isolated system

Question 25

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.

Answer 25

Law of Conservation of Mass, equal to

Question 26

In biological reactions, the application of a _____________ becomes straightforward if we have_________________________________________

Answer 26

material balance,

o compositions of substrates
o products, and
o cellular materials.

Question 27

in the realm of biochemical reactions, the determination of _________ often necessitates not only elemental balances but also _____________

Answer 27

stoichiometric coefficients, electron-proton balances

Question 28

accurately establishing the quantitative relationships between the various components

Answer 28

elemental balances
electron-proton balances

Question 29

All atoms of carbon, hydrogen, oxygen, nitrogen, and other elements consumed during growth  incorporated into _____________________________________

Answer 29

new cells or excreted as products.

Question 30

Once the identity of the substrate (carbon source) is known, ___________ and contains no unknown variables.

Answer 30

CwHxOyNz is fully specified

Question 31

chemical ‘formula’ for dry cells.

Answer 31

CHαOβNδ

Question 32

Escherichia coli Stoichiometric Equation Composition of Cells

Answer 32

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

Question 33

__________ of the biomass can be accounted for by four major elements ___________________________

Answer 33

90 to 95%, C, H, O, and N

Question 34

________ tend to have slightly higher _______ contents (11-14%) than _________ (6.39-9.0%).

Answer 34

Bacteria, nitrogen, fungi