Chapter 8, How Cellular Information Is Altered Video Solutions, Bioprocess Engineering

03:45

Problem 1

Would a cell with a point mutation or a deletion be more likely to revert back to the original phenotype? Why?

Dennis Howard

Numerade Educator

00:55

Consider the metabolic pathway based on aspartic acid shown in Section 4.9. Describe the procedure you would use to obtain a methionine overproducer. Use mutation-selection procedures, detailing the experiments to be done and their sequence.

Emily Himsel

Numerade Educator

02:28

Problem 3

You wish to isolate temperature-sensitive mutants (e.g., those able to grow at $30^{\circ} \mathrm{C}$ but not at $37^{\circ} \mathrm{C}$ ). Describe experiments to isolate such a cell.

Ummatul Choudary

Numerade Educator

02:46

Problem 4

An important method for screening for carcinogens is called the Ames test. The test is based on the potential for mutant cells of a microorganism to revert to a phenotype similar to the nonmutant. The rate of reversion increases in the presence of a mutagen. Many compounds that are mutagens are also carcinogens, and vice versa. Describe how you would set up an experiment and analyze the data to determine if nicotine is mutagenic.

Maryam Riaz

Numerade Educator

00:24

Problem 5

How many different hybridization probes must you make to ensure that at least one corresponds to a set of four codons encoding the amino acid sequence val-leu-trp-lys?

Sam Limsuwannarot

Numerade Educator

04:05

Problem 6

You wish to develop a genetically engineered $E$. coli producing a peptide hormone. You know the amino acid sequence of the peptide. Describe the sequence of steps you would use to obtain a culture expressing the gene as a peptide hormone.

Jennifer Stoner

Numerade Educator

03:31

Problem 7

You wish to produce a small protein using E. coli. You know the amino acid sequence of the protein. The protein converts a colorless substrate into a blue product. You have access to a high-copy-number plasmid with a penicillin-resistant gene and normal reagents for genetic engineering. Describe how you would engineer $E$. coli to produce this protein. Consider: source of donor DNA; regulatory elements that need to be included; how the donor and vector DNA are combined; how the vector DNA is inserted; and how you would select for a genetically engineered cell to use in production.

Dennis Howard

Numerade Educator

04:35

Problem 8

You wish to express a particular peptide in $E$. coli using a high-copy-number plasmid. You have the amino acid sequence for the peptide.
a. Explain the experimental process for generating and selecting the genetically engineered $E$. coli using restriction enzymes, ligase, $E$ coli, plasmid with neomycin resistance, and the known amino acid sequence.
b. What control elements would you place on the plasmid to regulate expression and to prevent read-through?

Rachel Griffin

Numerade Educator

01:44

Problem 9

a. There are three primary methods for obtaining donor DNA when doing genetic engineering. What are those methods (two-to six-word descriptions of each are acceptable)?
b. You need to produce a protein from humans in $E$. coli. You do not know the primary amino acid sequence. You suspect that introns are present. Which method will you use to obtain the donor DNA?