Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemical Engineering > Cell Growth > Flashcards

Cell Growth Flashcards

1
Q

________ is autocatalytic

A

Growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Characterized by specific growth rate, μ

A

Cell Growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cell Growth

A

cells + substrate → extracellular products + new cells + original cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cell concentration can be measured directly and/or indirectly.

A

Measuring Cell Concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

__________: mass or cell number basis.

A

Direct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cell number counting: ______________

A

hemocytometer, plate counts and particle counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Advantage: accurate, typically low noise in measurement.

A

Counting Cells: Hemocytometer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Disadvantage: time consuming, carcinogenic, mutagenic stains.

A

Counting Cells: Hemocytometer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

petri dish or dilution plate counts: count colonies formed by individual cells (dilute sample)

A

Counting Cells: Plate Counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CFUs = ___________

A

colony forming units

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Advantages: counts viable cells, fairly accurate.

A

Counting Cells: Plate Counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Disadvantages: noisy, takes days.

A

Counting Cells: Plate Counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Particle counters (Coulter counter): measure particle size distributions.

A

Counting Cells: Particle Counters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Advantages: very quick, obtain a size distribution in addition to a count.

A

Counting Cells: Particle Counters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Disadvantages: solutions must be particle free for accurate count, hardware, expensive, complicated.

A

Counting Cells: Particle Counters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most common units to report biomass.

A

Mass Concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Obtained by centrifuging sample, drying and weighing.

A

Mass Concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Advantages: concentration Mass is typical variable in models, simple, low-tech method.

A

Mass Concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Disadvantages: Presence of solids makes inaccurate, difficult to measure low biomass concentrations.

A

Mass Concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Turbidimeter or spectrophotometer (most common).

A

Indirect Concentration Measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Substrate uptake or product evolution.

A

Indirect Concentration Measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Luciferin/ATP fluorescence

A

Indirect Concentration Measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Protein or DNA/RNA concentration measurements.

A

Indirect Concentration Measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Is a measure of the amount of light that passes through a turbid sample.

A

Optical density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Reported with the wavelength of the light used in the measurement. For example OD600 = optical density at 600 nm.

A

Optical density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

________ is often measured in OD and converted to mass per volume with a standard curve.

A

Biomass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Fixed amount of substrate (growth medium) present at beginning.

A

Batch Cultures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

_______ is seeded with an inoculum (small amount of live cells to start growth).

A

Batch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

5 phases of growth:___________

A

lag, exponential, deceleration, stationary, death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Adaptation as inoculum cells adjust enzyme systems to new environments (repression of unneeded systems, induction of useful enzyme systems).

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Growth is suppressed, duration 1-10 hours

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Extended by low temperature, small inoculum, radical substrate/temperature changes, low nutrient levels, inoculum “age”.

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Inoculum should be 5 volumes % and from exponential phase culture.

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

___________ can exist with multiple growth substrates (diauxic growth).

A

Multiple lag phases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Growth is balanced (intracellular concentrations remain constant).

A

Exponential Growth Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

No dependence on substrate concentration (growing at intrinsic maximum growth rate).

A

Exponential Growth Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Primary metabolites (growth associated) produced.

A

Exponential Growth Phase

38
Q

Growth rate is 1st order with respect to cell concentration, Oth order with respect to substrate concentration.

A

Exponential Growth Phase

39
Q

End of exponential phase.

A

Deceleration Phase

40
Q

Caused by either build-up of toxic products or depletion of substrate.

A

Deceleration Phase

41
Q

Cell physiology changes to favor survival overgrowth.

A

Deceleration Phase

42
Q

Net growth rate is zero.

A

Stationary phase

43
Q

Cells produce secondary metabolites (not growth associated).

A

Stationary phase

44
Q

Many products important to the biotechnology industry are produced during this phase.

A

Stationary phase

45
Q

Cells begin to lose ability to reproduce.

A

Stationary phase

46
Q

Cells begin to lyse, cryptic growth occurs.

A

Stationary phase

47
Q

Cells catabolize energy reserves (eg; PHB) in endogenous metabolism

A

Stationary phase

48
Q

Although growth slows or ceases, maintenance requirements still exist.

A

Stationary phase

49
Q

Death is relative to the population, death always occurs.

A

Death Phase

50
Q

Commonly modeled as a 1st order process with respect to biomass.

A

Death Phase

51
Q

Some portion of cells remain viable for a long time, but are altered

A

Death Phase

52
Q

Growth yield microorganisms = produced per unit substrate utilized

A

Growth Yield, Yield Coefficient

53
Q

_______________ is similarly affected relative to diffusion.

A

Biological reaction rate

54
Q

pH optima: _______________

A

bacteria 3-8, yeast 3-6 molds 3-7 plant cells 5-6, animal cells 6.5-7.5

55
Q

pH varies significantly during fermentation if system is not buffered or controlled for pH.

A

Effects of pH

56
Q

CO2 evolution and ammonium as nitrogen source both lower pH.

A

Effects of pH

57
Q

Nitrate utilization raises pH.

A

Effects of pH

58
Q

________ can become a limiting substrate.

A

DO

59
Q

At________ concentration, growth is independent of [O2].

A

high DO

60
Q

O₂ solubility in water ~____________

A

7 ppm (25°C, 1atm)

61
Q

Bacteria require ~___________

A

10% of saturation for [O2] independent growth, yeast 10-50%.

62
Q

_____________ is usually limited by stagnant liquid around bubbles.

A

Rate of O₂ transfer

63
Q

When O₂ transfer is limiting ____________ , so ….

A

OTR=OUR

64
Q

Very high maybe toxic to some organisms

A

Dissolved Carbon Dioxide

65
Q

Cells require certain DCO2 for proper metabolic functions

A

Dissolved Carbon Dioxide

66
Q

Controlled by changing CO2 conc. In air supply and agitation speed Ionic Strength

A

Dissolved Carbon Dioxide

67
Q

Affect the transport of certain nutrients in and out of the cell

A

Dissolved Carbon Dioxide

68
Q

Metabolic functions of cells

A

Dissolved Carbon Dioxide

69
Q

Solubility of certain nutrients

A

Dissolved Carbon Dioxide

70
Q

Structured versus unstructured (cell composition does not change with time).

A

Models for Growth Kinetics

71
Q

Segregated versus unsegregated (all cells are identical).

A

Models for Growth Kinetics

72
Q

_________ is an unstructured, unsegregated model.

A

Monod equation

73
Q

Single substrate controls growth. (low population density)

A

Monod equation

74
Q

Analogous to Michaelis-Menten enzyme kinetics and the Langmuir isotherm.

A

Monod equation

75
Q

Mechanistic if one enzyme system controlled growth

A

Monod equation

76
Q

Maintenance: _________________

A

energy expenditures for repair, transport, motility

77
Q

Endogenous metabolism: ____________

A

consumption of storage polymers for energy

78
Q

There are other nonsegregated, unstructured models for cell growth but the difference is not worth the work.

A

Other Models for Cell Growth

79
Q

___________ are not typically mechanistic, but are selected to fit data.

A

Inhibitory kinetic expressions

80
Q

__________ are analogous to inhibited enzyme kinetics.

A

Expressions

81
Q

If a substrate is inhibiting cell growth of a batch culture, the substrate should be added in a fed- batch mode.

A

Growth Inhibition by Substrate

82
Q

Inhibitory kinetic expressions are not typically mechanistic, but are selected to fit data.

A

Growth Inhibition by Product

83
Q

If a product inhibits cell growth of a batch culture, the product recovery will be expensive.

A

Growth Inhibition by Other Compounds

84
Q

Instrumentation

A

pH probe and controller
DO probe and controller
Antifoam probe and controller
Level probe and controller
Nutrient addition pump
Agitation rate controller

85
Q

Shuler uses ____ to represent changes in cell mass due to endogenous respiration and ka’ for changes in cell mass due to cell death and lysis.

A

Kd

86
Q

__________: catabolism of cellular reserves for continued maintenance and energy.

A

Endogenous respiration

87
Q

WWWebster’s Dictionary: 2.b) the quantitative relationship between two or more substances especially in processes involving physical or chemical change

A

Stoichiometry

88
Q

If cells have a characteristic molecular composition (i.e.; CH₂ON) then yield coefficients can be determined through stoichiometry. In practice, these estimates.

A

Stoichiometry

89
Q

The system is determinate and we can form the yield coefficients

A

Yield Coefficients

90
Q

from the stoichiometric coefficients and formula weights.

A

Yield Coefficients

Biochemical Engineering (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions