Becker's World of the Cell (9th Edition)
9th Edition
ISBN: 9780321934925
Author: Jeff Hardin, Gregory Paul Bertoni
Publisher: PEARSON
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Chapter 8, Problem 1Q
A researcher is studying a fern that is shown to have a membrane protein that transports the arsenate ion (HAsO42−), a common pollutant in ground water, across membranes and may be useful to clean polluted sites. However, after having injected the correct mRNA for the protein, the researcher failed to detect arsenate transport in the oocytes. What are the possible reasons for this?
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Part A
Shown above is a schematic diagram of the E. coli leader peptidase (Lep) which has several basic amino acids in a cytoplasmic loop. Propose a mutant of Lep that
would be a test of the "inside positive" rule for the orientation of proteins in membranes.
Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting
your answer.
terminal
reversed
same
(+)
(-)
center
1. Make mutant Lep that substitutes noncharged residues for the
chains in the loop, and put
charged side chains in
2. If the inside-positive rule applies, the mutant ought to have the
membrane.
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charged side
positions.
orientation in the
Shown below is a schematic diagram of the E. coli leader peptidase (Lep), which has several basic amino acids in a cytoplasmic loop. Propose a mutant of Lep that would be a test of the “inside positive” rule for the orientation of proteins in membranes.
1. Peroxisomes are organelles surrounded by a single membrane. Soluble proteins that
reside within peroxisomes are imported post-translationally, and they often contain
the C-terminal tripeptide SKL (serine-lysine-leucine).
a) How would you confirm that a C-terminal SKL tripeptide is a peroxisomal
targeting signal?
b) If cells were engineered to produce a hybrid protein consisting of a mitochondrial
matrix protein (including its signal sequence) followed by a C-terminal SKL
signal, where in the cell would you expect the hybrid protein to be found? Explain
your reasoning.
Chapter 8 Solutions
Becker's World of the Cell (9th Edition)
Ch. 8 - What is the difference between the concentration...Ch. 8 - Prob. 8.2CCCh. 8 - A researcher is studying a fern that is shown to...Ch. 8 - How are carrier proteins and channel proteins...Ch. 8 - How would you determine whether a specific...Ch. 8 - Both the Na+/glucose symporter and the Na+/K+ pump...Ch. 8 - You are studying the energetics of transport of...Ch. 8 - True or False? Indicate whether each of the...Ch. 8 - Telling Them Apart. From the following list of...Ch. 8 - Mechanisms of Transport. For each of the following...
Ch. 8 - Prob. 8.4PSCh. 8 - Prob. 8.5PSCh. 8 - Prob. 8.6PSCh. 8 - QUANTITATIVE Sodium Ion Transport. A marine...Ch. 8 - Prob. 8.8PSCh. 8 - Prob. 8.9PSCh. 8 - QUANTITATIVE The Calcium Pump of the Sarcoplasmic...Ch. 8 - Inverted Vesicles. An important advance in...Ch. 8 - Ouabain Inhibition. Ouabain is a specific...
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