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CHE 339/BME 339/BIO 335
Exam I
Thursday, October 7, 2010
Your name ________________________________
ANSWERS IN PENCIL CANNOT BE SUBMITTED FOR REGRADE
Part 1: Short Questions:
ANSWER IN THE SPACE PROVIDED
1. Cell growth (20 points total)
A.
Name 4 ways for measuring cell growth
(4 points).
 Direct Counting
 Dry cell weights
 Turbidity measurements
 Indirect measurements (metabolites, COM)
B.
Briefly (no more than 5 words each) describe 4 important biochemical events that occur
when cells enter stationary phase
(6 points).
 Sigma factors (change of genetic profiles)
 Nutrient accumulations
 Quorum sensing
 Secondary metabolites (i.e. antibiotics)
C.
What are secondary metabolites and why are they important?
(2 points)
Secondary metabolites are not related to primary metabolism nor involved in normal
growth/cell viability. They are formed during stationary phase.
D.
Your boss asked you to determine the
μ
max
Ks and Y
x/s
values for the organism
Longhornious pestis
which was recently discovered at the Royal Memorial stadium and was shown
to grow with glucose as the C source.
You have in your disposal a continuous stirred tank
fermenter, growth media, a spectrophotometer and a kit that allows you to measure the conc of
glucose in a solution.
Describe what experiments you would need to do, the data you will have to
obtain and how you will plot the data to calculate the parameters you need
(8 points).
•
Use chemostat to grow bacteria at various inlet substrate levels (Sin) and dilution rates
(D)
•
Measure Sout
(S) at exponential phase
•
After obtaining
the various data points [substrate levels (S), dilution rates (D)], plot their
inverse values from the Monod Kinetics model
•
to fit the Lineweaver Burk equation
1/D = Ks/umax * 1/S + 1/umax
•
Yintercept gives 1/umax and Slope gives Ks/umax > Ks
•
Measure cell mass out (X) and Sout (S) during exponential phase and use X=Y
X/S
(SinS) to get Y
X/S
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View Full Document 2.
Oxygen transfer [8 points total]
A. How does the Oxygen Transfer Rate (OTR) depend on the interfacial area and the
driving force for mass transfer (i.e. write the equation and explain the meaning of the terms
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This note was uploaded on 12/13/2011 for the course BME 339 taught by Professor Georgiou during the Spring '11 term at University of Texas at Austin.
 Spring '11
 Georgiou

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