Draw the structure of the N−phenylthiohydantoin formed by
initial Edman degradation of the peptide Ala―Gly―Phe―Phe. Do...
Draw the structure of the N−phenylthiohydantoin formed by
initial Edman degradation of the peptide Ala―Gly―Phe―Phe. Do not
draw wedges or dashes in your answer.
Examine the following peptide then answer parts a-c
Lys-Asp-Pro-Leu-Trp-Ala-His-Met-Gln-Phe-Gly-Arg
a.estimate the net charge at pH 7
B.estimate the net charge at pH 12
For the peptide below
Thr, Ser, Tyr, Met, Asp, Phe, His, Lys, Trp, Gly, Pro, Arg, Ile,
Glu
Calculate overall charge for pH=5 and pH=11 Calculate overall
pI
QUESTION 6 Which of the following peptides is most likely an
alpha helix?
Arg-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Asp
Glu-Ala-Tyr-Pro-Met-Gly-Val-Leu-Ser-Lys
Glu-Ala-Tyr-Phe-Met-Gln-Val-Leu-Ser-Lys
Arg-Ala-Tyr-Phe-Met-Gln-Val-Leu-Ser-Asp
A peptide has the following sequence: A-K-R-H-G-E-E-R
(Ala-Lys-Arg-His-Gly-Glu-Glu-Arg). What is the pI for this peptide?
You can use even integer approximations for pKa values:
I know the answer is 9.5 but I need to know how to get to this
answer.
The amino acid sequence of human adrenocorticotropin, a
polypeptide hormone, is:
Ser-Tyr-Ser-Met-Glu-His-Glu-Arg-Trp-Gly-Lys-Pro-Val-Gly-Lys-Lys-Arg-Arg-Pro-Val-Lys-Val-Tyr-Pro-Asp-Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Glu-Pro-Leu-Glu-Phe
a)What is the approximate net charge of this molecule at pH 3? ph
7? ph 9? Assume that the pKs of the terminal -NH3+ and -COOH groups
are 7.8 and 3.6, respectively.
which rptoleyic enzye would cleave this peptide into the most
fragments?
Asn-Met-Thr-Gln-Gly-Arg-Cys-Lys-Val-Asn-Thr-Phe-Val-His-Glu-Leu-Val-Asp-Val-Cys-Phe-Lys-Glu
A. Trypsin B.Chymotrypsin C.Thermolysint D.they would all given an
equal amou
a) Draw the complete covalent structure of the tripeptide
Met-Tyr-Arg, with trans peptide bonds, as it would exist at pH
7.
b) Write the 1-letter code for each of the three amino acids
below the structure.
c) What is the overall charge of this peptide at pH 7?
d) What is the overall charge at pH 12?
e) This tri-peptide is reacted with 6M HCl and heat, which
breaks-up the individual peptide bonds. The mixture of the 3 amino
acids...
Draw the complete Lewis structure (including lone pairs of
electrons) for the anion that is formed after acetic acid has lost
its acidic hydrogen. Can you draw more than one structure? What do
you call it when more than one Lewis Structure is possible for an
ion or a molecule
1) Draw the structure of the product formed by addition of
vitamin B1 and benzaldehyde.
2) Ammonia adds to carbonyl groups but is ineffective as a
catalyst for the benzoin condensation. Explain.
3) Write a balanced oxidation-reduction equation for the
oxidation of benzoin by ammonium nitrate (the cupric ion
catalysis need not to be considered).
4) In the benzil oxidation the initial blue color changes to
gren as the reaction proceeds. Why?
5) In dilantin sodium it is the imide...
1) Draw the structure of the product formed by addition of
vitamin B1 and benzaldehyde.
2) Ammonia adds to carbonyl groups but is ineffective as a
catalyst for the benzoin condensation. Explain.
3) Write a balanced oxidation-reduction equation for the
oxidation of benzoin by ammonium nitrate (the cupric ion
catalysis need not to be considered).
4) In the benzil oxidation the initial blue color changes to
gren as the reaction proceeds. Why?
5) In dilantin sodium it is the imide...