MMSC490 UPDATED SCRIPTED EXAM QUESTIONS AND
SOLUTIONS GUARANTEE A+
Which of the following regulates genes by binding directly to transcription factor
proteins?
Insulin
Epinephrine
Steroid hormones
Growth hormone - ✔✔Steroid hormones
Binding of the activating nucleotide di- or triphosphate causes the Ras protein to (first)
undergo a conformational change.
separate into subunits.
split the terminal phosphate from the nucleotide-phosphate.
attach a farnesyl tail. - ✔✔undergo a conformational change.
Monomeric G proteins, such as Ras and several elongation factors, are usually in the
active state when a molecule of .................... is bound to them.
ADP
ATP
GTP
GDP - ✔✔GTP
Proteins are often regulated by phosphorylation by enzymes called
phosphoproteases.
protein phosphatases.
protein phosphorylases.
protein kinases. - ✔✔protein kinases.
Which of the following amino acids is not commonly phosphorylated to regulate protein
activity?
Tryptophan
Serine
Tyrosine
Threonine - ✔✔Tryptophan
Proteins can be regulated by the removal of phosphates by
protein kinases.
protein phosphorylases.
protein phosphatases.
,phosphoproteases. - ✔✔protein phosphatases
Which of the following is an example of a protein that is inhibited when bound to its
regulatory subunit(s) but becomes active when free?
Adenylyl cyclase
Phosphorylase kinase
cAMP-dependent protein kinase
Protein kinase C - ✔✔cAMP-dependent protein kinase
What happens to ubiquitin in proteosomes?
It has a GTP group added.
It is released and recycled.
It is phosphorylated.
It is degraded. - ✔✔It is released and recycled.
Which of the following statements regarding tRNAs is false?
There are several modified bases present in mature tRNAS.
tRNAS are approximately 70-80 bases long and form a cloverleaf structure.
tRNAs differ in sequence only at the anticodon.
All tRNAs have a CCA sequence at their 3ʹ terminus. - ✔✔tRNAs differ in sequence only
at the anticodon.
Which of the following statements about the attachment of amino acids to tRNAs is
false?
The amino acid is transferred to the 3ʹ end of the tRNA.
Two molecules of ATP are required for the process, one at each step.
The amino acid is first joined to AMP, forming an aminoacyl AMP intermediate.
Aminoacyl tRNA synthetases catalyze the reaction. - ✔✔Two molecules of ATP are
required for the process, one at each step.
The primary function of rRNAs in the ribosome is
to assist in the proper folding of ribosomal proteins.
to catalyze peptide bond formation.
to serve as a scaffold for the ribosomal proteins.
to assist in the proper positioning of tRNAs along the mRNA template. - ✔✔to catalyze
peptide bond formation.
The initiator codon in prokaryotes is
the first 5ʹ AUG of the mRNA.
recognized by scanning of the ribosome downstream of the 5ʹ methylguanosine cap.
, the first codon located at the 5ʹ end of the mRNA.
recognized via the Shine-Dalgarno sequence. - ✔✔recognized via the Shine-Dalgarno
sequence.
Which of the following statements about translational initiation is false?
5ʹ 7-methylguanosine caps serve as the point of recognition and binding for ribosomes
in eukaryotic cells.
In prokaryotes, ribosomes often bind the mRNA and can scan 5ʹ or 3ʹ until recognizing a
Shine-Dalgarno sequence.
Initiation codons in prokaryotic cells are preceded by Shine-Dalgarno sequences.
Viral mRNAs contain internal ribosome entry sites that allow ribosomes to bind to an
internal site of the mRNA. - ✔✔In prokaryotes, ribosomes often bind the mRNA and can
scan 5ʹ or 3ʹ until recognizing a Shine-Dalgarno sequence.
Antibiotics are powerful medications that inhibit the growth of bacteria. They work at a
variety of levels, but many target the process of protein synthesis in the bacterial cell. In
the developing of an antibiotic, which of the following would be an effective strategy or
target for the drug?
Inhibition of aminoacyl tRNA binding
All of the above
Induction of premature polypeptide chain termination
Inhibition of translational initiation - ✔✔All of the above
Which of the following processes does not require the assistance of chaperones?
Protein transport into the ER
Protein transport into the nucleus
Folding during protein synthesis
Assembly of proteins consisting of multiple polypeptide chains - ✔✔Protein transport
into the nucleus
The proteins shaped like a "double chamber" that are involved in protein folding are
called
peptidyl prolyl isomerases.
chaperonin proteins.
protein disulfide isomerases.
Hsp70 proteins. - ✔✔chaperonin proteins.
Signal sequences are sequences of hydrophobic amino acids that target membrane
translocation. Signal sequences are found
on the amino terminus of the 28S of certain ribosomal complexes associated with
secretion.
SOLUTIONS GUARANTEE A+
Which of the following regulates genes by binding directly to transcription factor
proteins?
Insulin
Epinephrine
Steroid hormones
Growth hormone - ✔✔Steroid hormones
Binding of the activating nucleotide di- or triphosphate causes the Ras protein to (first)
undergo a conformational change.
separate into subunits.
split the terminal phosphate from the nucleotide-phosphate.
attach a farnesyl tail. - ✔✔undergo a conformational change.
Monomeric G proteins, such as Ras and several elongation factors, are usually in the
active state when a molecule of .................... is bound to them.
ADP
ATP
GTP
GDP - ✔✔GTP
Proteins are often regulated by phosphorylation by enzymes called
phosphoproteases.
protein phosphatases.
protein phosphorylases.
protein kinases. - ✔✔protein kinases.
Which of the following amino acids is not commonly phosphorylated to regulate protein
activity?
Tryptophan
Serine
Tyrosine
Threonine - ✔✔Tryptophan
Proteins can be regulated by the removal of phosphates by
protein kinases.
protein phosphorylases.
protein phosphatases.
,phosphoproteases. - ✔✔protein phosphatases
Which of the following is an example of a protein that is inhibited when bound to its
regulatory subunit(s) but becomes active when free?
Adenylyl cyclase
Phosphorylase kinase
cAMP-dependent protein kinase
Protein kinase C - ✔✔cAMP-dependent protein kinase
What happens to ubiquitin in proteosomes?
It has a GTP group added.
It is released and recycled.
It is phosphorylated.
It is degraded. - ✔✔It is released and recycled.
Which of the following statements regarding tRNAs is false?
There are several modified bases present in mature tRNAS.
tRNAS are approximately 70-80 bases long and form a cloverleaf structure.
tRNAs differ in sequence only at the anticodon.
All tRNAs have a CCA sequence at their 3ʹ terminus. - ✔✔tRNAs differ in sequence only
at the anticodon.
Which of the following statements about the attachment of amino acids to tRNAs is
false?
The amino acid is transferred to the 3ʹ end of the tRNA.
Two molecules of ATP are required for the process, one at each step.
The amino acid is first joined to AMP, forming an aminoacyl AMP intermediate.
Aminoacyl tRNA synthetases catalyze the reaction. - ✔✔Two molecules of ATP are
required for the process, one at each step.
The primary function of rRNAs in the ribosome is
to assist in the proper folding of ribosomal proteins.
to catalyze peptide bond formation.
to serve as a scaffold for the ribosomal proteins.
to assist in the proper positioning of tRNAs along the mRNA template. - ✔✔to catalyze
peptide bond formation.
The initiator codon in prokaryotes is
the first 5ʹ AUG of the mRNA.
recognized by scanning of the ribosome downstream of the 5ʹ methylguanosine cap.
, the first codon located at the 5ʹ end of the mRNA.
recognized via the Shine-Dalgarno sequence. - ✔✔recognized via the Shine-Dalgarno
sequence.
Which of the following statements about translational initiation is false?
5ʹ 7-methylguanosine caps serve as the point of recognition and binding for ribosomes
in eukaryotic cells.
In prokaryotes, ribosomes often bind the mRNA and can scan 5ʹ or 3ʹ until recognizing a
Shine-Dalgarno sequence.
Initiation codons in prokaryotic cells are preceded by Shine-Dalgarno sequences.
Viral mRNAs contain internal ribosome entry sites that allow ribosomes to bind to an
internal site of the mRNA. - ✔✔In prokaryotes, ribosomes often bind the mRNA and can
scan 5ʹ or 3ʹ until recognizing a Shine-Dalgarno sequence.
Antibiotics are powerful medications that inhibit the growth of bacteria. They work at a
variety of levels, but many target the process of protein synthesis in the bacterial cell. In
the developing of an antibiotic, which of the following would be an effective strategy or
target for the drug?
Inhibition of aminoacyl tRNA binding
All of the above
Induction of premature polypeptide chain termination
Inhibition of translational initiation - ✔✔All of the above
Which of the following processes does not require the assistance of chaperones?
Protein transport into the ER
Protein transport into the nucleus
Folding during protein synthesis
Assembly of proteins consisting of multiple polypeptide chains - ✔✔Protein transport
into the nucleus
The proteins shaped like a "double chamber" that are involved in protein folding are
called
peptidyl prolyl isomerases.
chaperonin proteins.
protein disulfide isomerases.
Hsp70 proteins. - ✔✔chaperonin proteins.
Signal sequences are sequences of hydrophobic amino acids that target membrane
translocation. Signal sequences are found
on the amino terminus of the 28S of certain ribosomal complexes associated with
secretion.
