BCH5413 Exam 3 Exam A+ Questions and
Answers Verified Solutions Latest Update
2026/2027
Answer:
The structure of the ribosome is dependent on the ribosomal RNA and how they might base pair
with each other at different segments.
●● The ribosome consists of both ribosomal RNA and ribosomal proteins.
Which part contains the peptidyl transferase activity?.
Answer:
The 50S subunit (large subunit) contains the peptidyl transferase activity.
●● The ribosome consists of both ribosomal RNA and ribosomal proteins.
Which part contains the GTP hydrolysis activity?.
Answer:
The 50S subunit (large subunit) contains GTPase activity.
●● During protein synthesis, what kind of bond joins the amino acids? Which parts (functional
groups) of the amino acids are bonded together?.
Answer:
The 50S subunit links amino acids together through peptide bonds. Amino acids connect to form a
peptide bond through a reaction between the amino group and carboxyl group. A peptide bond is
formed through a dehydration reaction. This involves the removal of two hydrogens and an oxygen.
●● tRNA Charging: How does the aminoacyl-tRNA synthetases recognize which tRNA gets its
amino acid?.
Answer:
Recognition will depend on nucleotides within the tRNA and binding sites within the protein.
●● tRNA Charging: Describe the 2-step process for charging the tRNA..
Answer:
,The first step is the activation of the amino acid with the help of ATP to form aminoacyl-AMP. The
second step will use the energy from the aminoacyl-AMP bond to transfer the amino acid onto the
acceptor stem of the tRNA.
●● tRNA charging: Where does the amino acid get added to the tRNA? Be specific about the end
of the RNA and the position of binding on the RNA..
Answer:
The high-energy bond between the aminoacyl and AMP will be used to transfer the amino acid to
the 3' end of the tRNA; specifically, the amino acid will form an ester bond between the 3'carbon
hydroxyl
group on the adenosine of the tRNA and the carboxyl group of the amino acid.
●● What is the wobble hypothesis? What is its significance?.
Answer:
The wobble hypothesis is: The 3rd position base on a codon which is allowed to be different to
accommodate different tRNA, this exception allows it to form a non Watson-Crick base pair with
the anticodon.
This is significant because the wobble allows some aminoacyl-tRNAs to pair with more than one
codon
●● True/False: Protein synthesis requires GTP..
Answer:
TRUE, When binding an aminoacyl-tRNA to the A site
●● True/False: Wobble allows the different aminoacyl-tRNA to pair with same codon..
Answer:
TRUE, 3rd base of a codon is allowed to move slightly from it snormal position, allowing same
aminoacryl-tRNAs to pair with more than one codon
●● True/False: Ligase enzyme joins the amino acids to the respective tRNAs.
Answer:
FALSE, AA attached by ester bond between 2'-OH of terminal adenosine of tRNA
●● True/False: Aminoacylation of tRNAs requires GTP.
Answer:
, FALSE, 2 step process reuire AMP from ATP to activate AA, then,AMP is used to transfer the AA
to tRNA
●● True/False: Fmet-tRNA is the initiator tRNA in Eukaryotes.
Answer:
FALSE, N-Formylmethionine=Fmet-tRNA is the initiator of Prokaryotes
●● What differences are there between the ribosome binding in prokaryotes vs. eukaryotes?.
Answer:
During translation in prokaryotes, the ribosome binds an operon at a ribosome binding site that
precedes an open reading frame. Once the ribosome binds, there are various soluble factors that
ensure the ribosome reads the correct code to make the correct protein.During translation in
eukaryotes, the ribosome binds the 5' cap, then scans the mRNA for the AUG start site. The
ribosome also requires soluble factors to initiate translation.
●● What is the function of IF1?.
Answer:
binds to the A site and keeps the fmet-tRNA from binding there
●● What is the function of IF2?.
Answer:
binds to the fmet-tRNA and GTP and brings the complex to the P site
●● What is the function of IF3?.
Answer:
binds to 30S subunit to keep it separate from the large subunit
●● What is the function of hydrolysis of GTP after 70s initiation complex is formed?.
Answer:
releases IF2 and GDP from the complex so polypeptide chain elongation can begin
●● Explain the three steps in formation of 70s complex..
Answer:
Answers Verified Solutions Latest Update
2026/2027
Answer:
The structure of the ribosome is dependent on the ribosomal RNA and how they might base pair
with each other at different segments.
●● The ribosome consists of both ribosomal RNA and ribosomal proteins.
Which part contains the peptidyl transferase activity?.
Answer:
The 50S subunit (large subunit) contains the peptidyl transferase activity.
●● The ribosome consists of both ribosomal RNA and ribosomal proteins.
Which part contains the GTP hydrolysis activity?.
Answer:
The 50S subunit (large subunit) contains GTPase activity.
●● During protein synthesis, what kind of bond joins the amino acids? Which parts (functional
groups) of the amino acids are bonded together?.
Answer:
The 50S subunit links amino acids together through peptide bonds. Amino acids connect to form a
peptide bond through a reaction between the amino group and carboxyl group. A peptide bond is
formed through a dehydration reaction. This involves the removal of two hydrogens and an oxygen.
●● tRNA Charging: How does the aminoacyl-tRNA synthetases recognize which tRNA gets its
amino acid?.
Answer:
Recognition will depend on nucleotides within the tRNA and binding sites within the protein.
●● tRNA Charging: Describe the 2-step process for charging the tRNA..
Answer:
,The first step is the activation of the amino acid with the help of ATP to form aminoacyl-AMP. The
second step will use the energy from the aminoacyl-AMP bond to transfer the amino acid onto the
acceptor stem of the tRNA.
●● tRNA charging: Where does the amino acid get added to the tRNA? Be specific about the end
of the RNA and the position of binding on the RNA..
Answer:
The high-energy bond between the aminoacyl and AMP will be used to transfer the amino acid to
the 3' end of the tRNA; specifically, the amino acid will form an ester bond between the 3'carbon
hydroxyl
group on the adenosine of the tRNA and the carboxyl group of the amino acid.
●● What is the wobble hypothesis? What is its significance?.
Answer:
The wobble hypothesis is: The 3rd position base on a codon which is allowed to be different to
accommodate different tRNA, this exception allows it to form a non Watson-Crick base pair with
the anticodon.
This is significant because the wobble allows some aminoacyl-tRNAs to pair with more than one
codon
●● True/False: Protein synthesis requires GTP..
Answer:
TRUE, When binding an aminoacyl-tRNA to the A site
●● True/False: Wobble allows the different aminoacyl-tRNA to pair with same codon..
Answer:
TRUE, 3rd base of a codon is allowed to move slightly from it snormal position, allowing same
aminoacryl-tRNAs to pair with more than one codon
●● True/False: Ligase enzyme joins the amino acids to the respective tRNAs.
Answer:
FALSE, AA attached by ester bond between 2'-OH of terminal adenosine of tRNA
●● True/False: Aminoacylation of tRNAs requires GTP.
Answer:
, FALSE, 2 step process reuire AMP from ATP to activate AA, then,AMP is used to transfer the AA
to tRNA
●● True/False: Fmet-tRNA is the initiator tRNA in Eukaryotes.
Answer:
FALSE, N-Formylmethionine=Fmet-tRNA is the initiator of Prokaryotes
●● What differences are there between the ribosome binding in prokaryotes vs. eukaryotes?.
Answer:
During translation in prokaryotes, the ribosome binds an operon at a ribosome binding site that
precedes an open reading frame. Once the ribosome binds, there are various soluble factors that
ensure the ribosome reads the correct code to make the correct protein.During translation in
eukaryotes, the ribosome binds the 5' cap, then scans the mRNA for the AUG start site. The
ribosome also requires soluble factors to initiate translation.
●● What is the function of IF1?.
Answer:
binds to the A site and keeps the fmet-tRNA from binding there
●● What is the function of IF2?.
Answer:
binds to the fmet-tRNA and GTP and brings the complex to the P site
●● What is the function of IF3?.
Answer:
binds to 30S subunit to keep it separate from the large subunit
●● What is the function of hydrolysis of GTP after 70s initiation complex is formed?.
Answer:
releases IF2 and GDP from the complex so polypeptide chain elongation can begin
●● Explain the three steps in formation of 70s complex..
Answer:
