Bio chem Exam 2 Solved Papers - Questions with Complete Solutions.

Bio chem Exam 2 Solved Papers - Questions
with Complete Solutions
What is the highest level of protein structure in each of the protein
examples below:

-Gly-Ala-Val-Leu
C
on


-A single helical chain of collagen
fid


-myoglobin with heme
en


-hemoglobin - Correct Answers ✅Primary: Gly-Ala-Val-Leu
tia
l



Secondary: a single helical chain of collagen
co
nt
ac



Tertiary Structure: myoglobin with heme
tB
ria



Quaternary Structure: hemoglobin
nr
ey
an



draw the structure for the peptide bond below:
y@
gm



+H3N-C(CH3)H-C(=O)-NH-CH2-COO- - Correct Answers ✅+H3N-
ai


C(CH3)H-CO=N+H-CH2-COO-
l.c
om



based on the chemical properties of the residues, which of the
following

sequences could form the following:

,Bio chem Exam 2 Solved Papers - Questions
with Complete Solutions

-most likely an amphipathic alpha helix

-most likely an amphipathic beta sheet
C
on


-most likely a turn/loop
fid



-not amphipathic
en
tia
l


ala-phe-leu-val-ile-trp-phe-val-ala
co


lys-gln-asn-glu-pro-arg-ala-asn-glu
nt


gln-ile-thr-phe-thr-leu-gln-val-ser
ac
tB


asn-leu-ala-asp-ser-phe-arg-gln-ile - Correct Answers ✅-most
likely an amphipathic alpha helix:
ria



asn-leu-ala-asp-ser-phe-arg-gln-ile
nr
ey
an



-most likely an amphipathic beta sheet:
y@



gln-ile-thr-phe-thr-leu-gln-val-ser
gm
ai


-most likely a turn/loop:
l.c
om


lys-gln-asn-glu-pro-arg-ala-asn-glu



-not amphipathic:

,Bio chem Exam 2 Solved Papers - Questions
with Complete Solutions
ala-phe-leu-val-ile-trp-phe-val-ala



a small generic section of the primary structure of an alpha helix
C
on


is given below:
fid
en


AA1-AA2-AA3-AA4-AA5-AA6-AA7
tia
l



a. which amino acid residue's backbone forms a hydrogen bond
co



with the backbone of the 7th residue?
nt
ac
tB



b. which of the following peptide segments is most likely to be
ria


part of a stable alpha helix at physiological pH?
nr


-glu-leu-ala-lys-phe
ey



-glu-glu-glu-glu-glu
an
y@


-gly-gly-gly-ala-gly

-pro-leu-thr-pro-trp
gm



-gly-arg-lys-his-gly
ai
l.c


-tyr-trp-phe-val-ile
om



-lys-lys-ala-arg-ser - Correct Answers ✅a. 3



b. glu-leu-ala-lys-phe

, Bio chem Exam 2 Solved Papers - Questions
with Complete Solutions

alhpa helices are a type of secondary structure in proteins. what is
the length of a 39-kDa single stranded alpha helical protein
C


segment.
on
fid


assume the residue mass is 110Da - Correct Answers ✅531.82 A
en
tia


a segment of a single chain in an antiparallel beta sheet has a
l


length of 144A. how many residues are in this segment - Correct
co


Answers ✅41
nt
ac



sort the following as descriptions of alpha helices, beta sheets,
tB



beta turns, or all.
ria
nr
ey


-successive R groups point in opposite directions
an



-1st residue hydrogen-bonded to 5th residue (that is, residue n is
y@


H-bonded to residue n+4)
gm


-all -NH groups point in the same direction
ai


-1st residue HB to the 4th residue(residue n is Hbonded to residue
l.c


n +3)
om



-contains -NH hydrogen bonded to c=o - Correct Answers ✅Beta
sheets:

-successive R groups point in opposite directions