Homework Answers
In an aqueous medium, the amide groups forming the hydrogen bonds, which stabilize the alpha helix, prefer to form hydrogen bonds with the water molecules. This makes an isolated alpha helix unstable and rare in a soluble protein.
A fibrous protein from a tropical terrestrial gastropod (snail) has just been isolated and characterized. The...
A fibrous protein from a tropical terrestrial gastropod (snail) has just been isolated and characterized. The protein was found to consist of a single polypeptide chain in an α- helix, with a relatively long pitch of 8.3Å, much longer than is typical of proteins. There are a total of 623 amino acids in the protein. What is the approximate length of the polypeptide? (Assume the typical rotation of 100o per amino acid.)
A protein with the sequence below forms an alpha-helix. How many turns are made in the...
A protein with the sequence below forms an alpha-helix. How many turns are made in the helix? Explain why the properties of the amino acids in this helix result in an amphipathic protein. How might this amphipathic alpha-helix associate with the membrane? Leu-Lys-Arg-Ile-Val-Asp-Thr-Ile-Leu-Ser-Arg-Leu-Phe-Lys
(2%) Indicate which secondary structure or structures (α -helix, β -pleated, random coil) will the following...
(2%) Indicate which secondary structure or structures (α -helix,
β -pleated, random coil) will the following peptide adopt in an
aqueous solution at pH 7
(2%) The unfolding of the alpha helix of a polypeptide to a
randomly coiled conformation is accompanied by a large decrease in
a property called specific rotation, a measure of
a solution’s capacity to rotate circularly polarized light.
Polyglutamate, a polypeptide made up of only L-Glu residues, has
the alpha helical
conformation at pH 3....
If you had to mutate a Phe residue that occurs in a helix within a protein,...
If you had to mutate a Phe residue that occurs in a helix within a protein, but wanted to disturb the structure of the globular protein as little as possible, what amino acid might be a good choice, and why?
Protein usually present in the urine after intense exercise, but not seen normally. Why is that?
Protein usually present in the urine after intense exercise, but not seen normally. Why is that?
3. You are characterizing an isolated membrane protein. The protein is exposed on both sides of...
3. You are characterizing an isolated membrane protein. The protein is exposed on both sides of the membrane. Over much of the central part of its surface, there are hydrophobic amino acids, while the ends are hydrophilic. It crosses the membrane a number of times. There is an opening in the center of this protein lined by hydrophilic amino acids. What kind of protein is this and what is its probable function?
11.Which of the following mutations would most likely to disrupt the structure of an α-helix? Cys...
11.Which of the following mutations would most likely to disrupt the structure of an α-helix? Cys to Ala Lys to Arg Glu to Gly Val to Leu 12.Which amino acid combination is the most preferred to occupy positions 1 and 4 in an α-helix? Glu and Lys Phe and Pro Lys and Arg Asp and Glu 13.If each turn in the standard alpha helix extends 5.4 A and there are 3.6 amino acid residues per turn, how many amino acids...
2. Bacteriorhodopsin is a membrane protein that contains seven closely packed α helices that span a...
2. Bacteriorhodopsin is a membrane protein that contains seven closely packed α helices that span a membrane bilayer. Two fluorescent labels have been specifically placed onto different a helical sections of the protein to estimate the distance from one helix to another. The labels (DNS and Phe) are used such that R, is equal to 2.7 nm. The energy transfer efficiency is found to be equal to 0.045 Estimate the distance between these two labeled α helices of bacteriorhodopsin
Explain why α-helices are most commonly observed in transmembrane protein sequences when the distance from one...
Explain why α-helices are most commonly observed in
transmembrane protein sequences when the distance from one side of
a membrane to the other can be spanned by significantly fewer amino
acids in a β-strand conformation.
Match the items in the left column to the appropriate blanks in
the sentences on the right.
prevents within a The structure of an a-helix promotes stretch of amino acids, and at the same time contiguous interactions with other important molecules involved in in the...
Explain why α-helices are most commonly observed in transmembrane protein sequences when the distance from one...
Explain why α-helices are most commonly observed in
transmembrane protein sequences when the distance from one side of
a membrane to the other can be spanned by significantly fewer amino
acids in a β-strand conformation.
Match the items in the left column to the appropriate blanks in
the sentences on the right.
noncontiguous The structure of an a-helix promotes within a stretch of amino acids, contiguous and at the same time interactions with other important molecules involved in in the...
(2%) Indicate which secondary structure or structures (α -helix,
β -pleated, random coil) will the following peptide adopt in an
aqueous solution at pH 7
(2%) The unfolding of the alpha helix of a polypeptide to a
randomly coiled conformation is accompanied by a large decrease in
a property called specific rotation, a measure of
a solution’s capacity to rotate circularly polarized light.
Polyglutamate, a polypeptide made up of only L-Glu residues, has
the alpha helical
conformation at pH 3....
2. Bacteriorhodopsin is a membrane protein that contains seven closely packed α helices that span a membrane bilayer. Two fluorescent labels have been specifically placed onto different a helical sections of the protein to estimate the distance from one helix to another. The labels (DNS and Phe) are used such that R, is equal to 2.7 nm. The energy transfer efficiency is found to be equal to 0.045 Estimate the distance between these two labeled α helices of bacteriorhodopsin
Explain why α-helices are most commonly observed in
transmembrane protein sequences when the distance from one side of
a membrane to the other can be spanned by significantly fewer amino
acids in a β-strand conformation.
Match the items in the left column to the appropriate blanks in
the sentences on the right.
prevents within a The structure of an a-helix promotes stretch of amino acids, and at the same time contiguous interactions with other important molecules involved in in the...
Explain why α-helices are most commonly observed in
transmembrane protein sequences when the distance from one side of
a membrane to the other can be spanned by significantly fewer amino
acids in a β-strand conformation.
Match the items in the left column to the appropriate blanks in
the sentences on the right.
noncontiguous The structure of an a-helix promotes within a stretch of amino acids, contiguous and at the same time interactions with other important molecules involved in in the...
Most questions answered within 3 hours.
-
Find the complete optimal solution to this linear programming
problem. Max 5x + 3y s.t. 2x...
asked 53 seconds ago -
The pH of an acetate buffer was determined to be 4.76. Then, a
few drops of...
asked 3 minutes ago -
a sample of size 1500 is used to find a confidence
interval for the percentage of...
asked 12 minutes ago -
Explain in detail the differences between qualitative and
quantitative forecasts. Include at least two examples of...
asked 17 minutes ago -
Differentiate between response time and throughput.
Explain how the physical design of a database influences
performance...
asked 19 minutes ago -
Write MATLAB code to plot the following
waveforms.
Rectangular pulses:
????(?)
????(? − ?)
????(?/?) ...
asked 19 minutes ago -
4. Adam’s Inc.’s outstanding common stock is currently selling
in the market for $28. Dividends of...
asked 30 minutes ago -
question
you were
asked to create a regression that will predict the amount of saving
for...
asked 37 minutes ago -
If tcalc = -2.78, tcrit = 1.96, H0: Mu > Mu0, and Xbar <
Mu0, what...
asked 59 minutes ago -
Circular distribution
•Suppose two birds are flying, one is flying from the north and
the other...
asked 58 minutes ago -
please answer all... it all counts as a discussion problem
1a qualitative data and proportions: Suppose...
asked 1 hour ago -
Typing The Answer Is Mandatory
Temperature is a measure of heat. More heat means that more...
asked 52 minutes ago