BIOCHEM ACS STUDY GUIDE questions with verified
answers
_____ adds new nucleotides to the _____ end of the elongating strand during
DNA
replication.
a. Polynucleotide phosphorylase; 3′
b. DNA polymerase: 3′
c. Sequenase; 5′
d. Replicase; 5′ Ans✓✓✓ B
________ acts as a structural disruptor in the middle of regular secondary
structure
elements such as alpha helices and beta sheets.
a. Serine
b. Glycine
c. Cysteine
d. Methionine
e. Proline Ans✓✓✓ E
________ reads the 3' to 5' strand of DNA creating an RNA copy by adding
nucleotides to
the ______ end of the new RNA strand.
a. Transcriptase, 5'
b. RNA polymerase, 3'
c. RNAse, 5'
,d. Polynucleotide phosphorylase, 3' Ans✓✓✓ B
A BLAST search compares a sequence of __________ to a database of known
sequences.
[Q42]
a. Proteins
b. Proteins or Amino Acids
c. Nucleotides or Amino -acids
d. Amino Acids
e. Nucleotides Ans✓✓✓ C
A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6 mol. wt.
247,500), lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt.
64,500) were applied in a pH 6.5 buffer to a DEAE-cellulose chromatography
column and eluted with the same buffer.
What was their order of elution?
A. urease, lactoglobin, catalase, hemoglobin
B. hemoglobin, catalase, lactoglobin, urease
C. urease, catalase, hemoglobin, lactoglobin
D. lactoglobin, hemoglobin, catalase, urease
E. cannot be determined from the information given Ans✓✓✓ B
A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6, mol. wt.
247,500),
lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt. 64,500)
were applied in a
,pH 6.5 buffer to a DEAE-cellulose chromatography column and eluted with the
same buffer.
What was their order of elution?
a. urease, lactoglobin, catalase, hemoglobin
b. lactoglobin, hemoglobin, catalase, urease
c. hemoglobin, catalase, lactoglobin, urease
d. urease, catalase, hemoglobin, lactoglobin
e. cannot be determined from the information given Ans✓✓✓ C
A peptide was found to have a molecular mass of about 650 and upon hydrolysis
produced Ala, Cys, Lys, Phe, and Val in a 1:1:1:1:1 ratio. The peptide upon
treatment with Sanger's reagent produced DNP-Cys and exposure to
carboxypeptidase produced valine. Chymotrypsin treatment of the peptide
produced a dipeptide that contained sulfur and has a UV absorbance, and a
tripeptide. Exposure of the peptide to trypsin produced a dipeptide and a
tripeptide. Deduce the sequence of the peptide.
A. Val-Ala-Lys-Phe-Cys
B. Cys-Lys-Phe-Ala-Val
C. Cys-Ala-Lys-Phe-Val
D. Cys-Phe-Lys-Ala-Val
E. Val-Phe-Lys-Ala-Cys Ans✓✓✓ D
A reagent commonly employed to cleave disulfide bonds in proteins is
A. 2,4-dinitrofluorobenzene
B. urea
C. 2-mercaptoethanol
, D. phenylisothiocyanate
E. cyanogen bromide Ans✓✓✓ C
A size extraction column...
a. tags larger molecules for separation
b slows down smaller molecules, allowing larger ones to flow through more
readily
c tags smaller molecules for separation
d slows down larger molecules, allowing smaller ones to flow through more easily
Ans✓✓✓ B
A β-D-aldopentofuranose has how many chiral carbons?
A. 0
B. 2
C. 3
D. 4
E. 5 Ans✓✓✓ D
According to the Second Law of Thermodymnamics,
A. the total entropy change in any reaction that occurs spontaneously must be
greater than 0.
B. the total entropy change in any reaction that occurs spontaneously must be
less than 0.
C. the total entropy of the universe remains constant.
D. the total entropy of the universe is always decreasing. Ans✓✓✓ A
answers
_____ adds new nucleotides to the _____ end of the elongating strand during
DNA
replication.
a. Polynucleotide phosphorylase; 3′
b. DNA polymerase: 3′
c. Sequenase; 5′
d. Replicase; 5′ Ans✓✓✓ B
________ acts as a structural disruptor in the middle of regular secondary
structure
elements such as alpha helices and beta sheets.
a. Serine
b. Glycine
c. Cysteine
d. Methionine
e. Proline Ans✓✓✓ E
________ reads the 3' to 5' strand of DNA creating an RNA copy by adding
nucleotides to
the ______ end of the new RNA strand.
a. Transcriptase, 5'
b. RNA polymerase, 3'
c. RNAse, 5'
,d. Polynucleotide phosphorylase, 3' Ans✓✓✓ B
A BLAST search compares a sequence of __________ to a database of known
sequences.
[Q42]
a. Proteins
b. Proteins or Amino Acids
c. Nucleotides or Amino -acids
d. Amino Acids
e. Nucleotides Ans✓✓✓ C
A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6 mol. wt.
247,500), lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt.
64,500) were applied in a pH 6.5 buffer to a DEAE-cellulose chromatography
column and eluted with the same buffer.
What was their order of elution?
A. urease, lactoglobin, catalase, hemoglobin
B. hemoglobin, catalase, lactoglobin, urease
C. urease, catalase, hemoglobin, lactoglobin
D. lactoglobin, hemoglobin, catalase, urease
E. cannot be determined from the information given Ans✓✓✓ B
A mixture of urease (pI = 5.1, mol. wt. 482,700), catalase (pI = 5.6, mol. wt.
247,500),
lactoglobin (pI 5.2, mol. wt. 37,100) and hemoglobin (pI 6.9, mol. wt. 64,500)
were applied in a
,pH 6.5 buffer to a DEAE-cellulose chromatography column and eluted with the
same buffer.
What was their order of elution?
a. urease, lactoglobin, catalase, hemoglobin
b. lactoglobin, hemoglobin, catalase, urease
c. hemoglobin, catalase, lactoglobin, urease
d. urease, catalase, hemoglobin, lactoglobin
e. cannot be determined from the information given Ans✓✓✓ C
A peptide was found to have a molecular mass of about 650 and upon hydrolysis
produced Ala, Cys, Lys, Phe, and Val in a 1:1:1:1:1 ratio. The peptide upon
treatment with Sanger's reagent produced DNP-Cys and exposure to
carboxypeptidase produced valine. Chymotrypsin treatment of the peptide
produced a dipeptide that contained sulfur and has a UV absorbance, and a
tripeptide. Exposure of the peptide to trypsin produced a dipeptide and a
tripeptide. Deduce the sequence of the peptide.
A. Val-Ala-Lys-Phe-Cys
B. Cys-Lys-Phe-Ala-Val
C. Cys-Ala-Lys-Phe-Val
D. Cys-Phe-Lys-Ala-Val
E. Val-Phe-Lys-Ala-Cys Ans✓✓✓ D
A reagent commonly employed to cleave disulfide bonds in proteins is
A. 2,4-dinitrofluorobenzene
B. urea
C. 2-mercaptoethanol
, D. phenylisothiocyanate
E. cyanogen bromide Ans✓✓✓ C
A size extraction column...
a. tags larger molecules for separation
b slows down smaller molecules, allowing larger ones to flow through more
readily
c tags smaller molecules for separation
d slows down larger molecules, allowing smaller ones to flow through more easily
Ans✓✓✓ B
A β-D-aldopentofuranose has how many chiral carbons?
A. 0
B. 2
C. 3
D. 4
E. 5 Ans✓✓✓ D
According to the Second Law of Thermodymnamics,
A. the total entropy change in any reaction that occurs spontaneously must be
greater than 0.
B. the total entropy change in any reaction that occurs spontaneously must be
less than 0.
C. the total entropy of the universe remains constant.
D. the total entropy of the universe is always decreasing. Ans✓✓✓ A
