BISC 261 Bolded Terms exam with Questions
Solved with 100% Correct Answers
polyribosome - Answer A complex of several ribosomes translating a single messenger
RNA.
amino acid activation - Answer The preparatory step of protein synthesis in which
amino acids are attached to transfer RNA molecules. The reaction is catalyzed by
aminoacyl-tRNA synthetases.
anticodon - Answer The three bases on a tRNA that are complementary to the codon
on mRNA.
aminoacyl/ acceptor site - Answer The ribosomal site that contains an aminoacyl-
tRNA at the beginning of the elongation cycle during protein synthesis.
peptidyl/ donor site - Answer The site on the ribosome that contains the peptidyl-
tRNA at the beginning of the elongation cycle during protein synthesis.
exit site - Answer The location on a ribosome to which an empty (uncharged)
tRNA moves from the P site before it finally leaves during protein synthesis.
,ribosome-binding site (RBS) - Answer Nucleotide sequences on mRNA recognized by
a ribosome, so that it orients properly on the mRNA and begins translation at the
appropriate codon.
initiator tRNA - Answer The tRNA that binds to the start codon during initiation
of translation.
initiation factors - Answer Proteins that function during initiation of protein synthesis.
deoxyribonucleic acid (DNA) - Answer A polynucleotide that constitutes the genetic
material of all cellular organisms. It is composed of deoxyribonucleotides connected
by phosphodiester bonds.
complementary - Answer Refers to the matching of two strands of DNA or RNA based
on the base-pairing rules.
ribonucleic acid (RNA) - Answer A polynucleotide composed of ribonucleotides joined
by phosphodiester bonds.
origin of replication - Answer A site on a chromosome or plasmid where DNA
replication is initiated.
replication fork - Answer The Y-shaped structure where DNA is replicated.
replicon - Answer A unit of the genome that contains an origin of replication and in
which DNA is replicated.
replisome - Answer A large protein complex that copies the DNA double helix to
form two daughter chromosomes.
, DNA polymerase - Answer An enzyme that synthesizes new DNA using a parental
nucleic acid strand (usually DNA) as a template.
helicases - Answer Enzymes that use ATP energy to unwind DNA ahead of the replication
fork.
topoisomerases - Answer Enzymes that change the topology of DNA molecules by
transiently breaking one or both strands. They play an important role in DNA
replication and transcription.
DNA gyrase - Answer A topoisomerase enzyme that relieves tension generated by
the rapid unwinding of DNA during DNA replication or transcription.
primosome - Answer in bacteria, a complex of proteins that includes the enzyme
primase, responsible for synthesizing the RNA primers needed for DNA replication.
leading strand - Answer The strand of DNA that is synthesized continuously during
DNA replication
lagging strand - Answer The strand of DNA synthesized discontinuously during
DNA replication.
okazaki fragments - Answer Short stretches of polynucleotides produced during
discontinuous DNA replication.
DNA ligase - Answer An enzyme that joins two DNA fragments through the formation of
a new phosphodiester bond.
Solved with 100% Correct Answers
polyribosome - Answer A complex of several ribosomes translating a single messenger
RNA.
amino acid activation - Answer The preparatory step of protein synthesis in which
amino acids are attached to transfer RNA molecules. The reaction is catalyzed by
aminoacyl-tRNA synthetases.
anticodon - Answer The three bases on a tRNA that are complementary to the codon
on mRNA.
aminoacyl/ acceptor site - Answer The ribosomal site that contains an aminoacyl-
tRNA at the beginning of the elongation cycle during protein synthesis.
peptidyl/ donor site - Answer The site on the ribosome that contains the peptidyl-
tRNA at the beginning of the elongation cycle during protein synthesis.
exit site - Answer The location on a ribosome to which an empty (uncharged)
tRNA moves from the P site before it finally leaves during protein synthesis.
,ribosome-binding site (RBS) - Answer Nucleotide sequences on mRNA recognized by
a ribosome, so that it orients properly on the mRNA and begins translation at the
appropriate codon.
initiator tRNA - Answer The tRNA that binds to the start codon during initiation
of translation.
initiation factors - Answer Proteins that function during initiation of protein synthesis.
deoxyribonucleic acid (DNA) - Answer A polynucleotide that constitutes the genetic
material of all cellular organisms. It is composed of deoxyribonucleotides connected
by phosphodiester bonds.
complementary - Answer Refers to the matching of two strands of DNA or RNA based
on the base-pairing rules.
ribonucleic acid (RNA) - Answer A polynucleotide composed of ribonucleotides joined
by phosphodiester bonds.
origin of replication - Answer A site on a chromosome or plasmid where DNA
replication is initiated.
replication fork - Answer The Y-shaped structure where DNA is replicated.
replicon - Answer A unit of the genome that contains an origin of replication and in
which DNA is replicated.
replisome - Answer A large protein complex that copies the DNA double helix to
form two daughter chromosomes.
, DNA polymerase - Answer An enzyme that synthesizes new DNA using a parental
nucleic acid strand (usually DNA) as a template.
helicases - Answer Enzymes that use ATP energy to unwind DNA ahead of the replication
fork.
topoisomerases - Answer Enzymes that change the topology of DNA molecules by
transiently breaking one or both strands. They play an important role in DNA
replication and transcription.
DNA gyrase - Answer A topoisomerase enzyme that relieves tension generated by
the rapid unwinding of DNA during DNA replication or transcription.
primosome - Answer in bacteria, a complex of proteins that includes the enzyme
primase, responsible for synthesizing the RNA primers needed for DNA replication.
leading strand - Answer The strand of DNA that is synthesized continuously during
DNA replication
lagging strand - Answer The strand of DNA synthesized discontinuously during
DNA replication.
okazaki fragments - Answer Short stretches of polynucleotides produced during
discontinuous DNA replication.
DNA ligase - Answer An enzyme that joins two DNA fragments through the formation of
a new phosphodiester bond.
