Researchers have described the
“binary patterning” of polar and nonpolar amino acids in the
sequences of proteins. In their code, polar and charged residues
like D, N, E, Q, K, H, and R are represented as open circles (○)
and nonpolar residues like F, L, I, M, and V as closed circles (●).
Thus, a polypeptide with the sequence asp-ile-his-phe-gln would be
represented as ○●○●○. Researchers analyzed the binary patterns of
isolated secondary structure elements (short pieces) from native
proteins....
Complete the table below and classify the following salts
(acidic, basic or neutral) and their pH ranges.
Salt
Ions
Reactions with water
Occurs?
Acidic/basic/neutral
pH ranges
(=7 or >7 or <7)
KF
K+
K+ + H2O ® KOH + H+
no
basic
pH > 7
F-
F+ + H2O ® HF + OH-
yes
NaBr
NH4I
NaBrO2
NaCH3COO
KNO3
FeBr3
Classify the following each of the 0.10 M solutions as either
acidic, basic, or neutral. Show equations and determine/calculate
the pH of each solution. You may need Ka or
Kb of original acid or base and Kw value to
perform each substance.
a) NaCl
b) NH4Cl
c) KNO2
d) NaF
e) KNO3
f) NH4NO3
g) KC2H3O2
Classify each of the following as a polar or a nonpolar bond. If
the bond is polar, represent the bond using delta notation.
Electronegativity vaules: N=3.0, O=3.5,S=2.5,Cl=3.0
N-O,N-Cl,N-S
1. Classify each bond as nonpolar covalent, polar covalent, or
ionicA. C-BrB. S-ClC. C-P2. What is the charge on each ion in these compounds?a. CaSb. MgF2 (small number 2 next to F)c. Cs2Od.ScCl3e.Al2S33. How many covalent bonds are normally formed by each
element?a. Nb.Fc.Cd.Bre.O
Given the following sequence: LHYEAIAKAWNDAF
a. Classify each amino acid into polar, non-polar, & charged
(at pH 7.0)–put a letter above each to show if polar (p), non-polar
(n), or charged (c).
b.What are the ionizable groups?
c.What is the order of the pKaʼs going from low to high pH
d.What is the isoelectric point (pl) of this peptide?
e.At the pHʼs of 3, 6, & 9, what is the charge state?
f.What type of secondary structure would this peptide...
For each of the following, is the solution acidic, basic,
neutral, or cannot be determined? For each, write the equation for
the dominant equilibrium which determined the pH, and justify your
pH prediction. Kw = 1.0 x 10-14
100 mL of 0.10 M NaH3P2O7; Ka1 = 3.0 x 10-2, Ka2 = 4.4 x 10-3,
Ka3 = 2.5 x 10-7, and Ka4 = 5.6 x 10-10 for H4P2O7.
100 mL of 0.10 M K2H2P2O7; see Part a for Ka values
100...