MMG 301 Exam 2 questions with verified
answers passed
Describe the central dogma of molecular biology - correct answer ✔✔DNA → RNA → Proteins
The Central Dogma is the process by which the instructions in DNA are converted into a
functional product (the protein) with the intermediary of the RNA.
The central dogma of molecular biology explains the flow of genetic information, from DNA to
RNA to Proteins
DNA→ RNA = transcription
They are the same "language" of nucleic acids
RNA → Proteins = translated
They are not the same language so it needs to be translated to this new language
List the types of genetic elements found in bacteria - correct answer ✔✔Chromosomes
Circular thread like structures made of DNA molecules that contain genes.
Plasmids
genetic element that can replicate separately from the chromosome
Double stranded circular DNA (few are linear)
,few thousand to hundreds of thousand of base pairs
have a region called the origin of replication (replication proceeds bidirectionally)
replication requires RNA primer
have genes such as those for antibiotic resistance
genes for conjugation (pilus and enzymes)
Describe the basic structure of an operon - correct answer ✔✔Single transcription unit.
(multiple genes being transcribed together)
Promoter (starts)
Coding genes ORF (g1g2 etc)
Terminator (stops)
Describe how a change in a nucleotide propagates through the various steps of information
transfer, especially for frame shifts and changes in key features. - correct answer ✔✔If you
change a single nucleotide in the DNA, you change the RNA and then you change the protein
made. If this change causes the codon to change, the whole protein could be wrong, not work,
or not be functional
Arrange in order the following DNA features and how they correspond to mRNA and protein. -
correct answer ✔✔The promoter (35 and 10)
+1 of transcription
Shine Dalgarno sequence (RBS)
Start Codon
Operators
coding sequence
stop codon
transcriptional terminator
, Diagram an RNA molecule including sites needed for translation initiation and termination -
correct answer ✔✔In bacteria the small ribosomal subunit attaches directly to certain
sequences in the mRNA. These Shine-Dalgarno sequences come just before start codons and
"point them out" to the ribosome.
In initiation, the ribosome assembles around the mRNA to be read and the first tRNA (carrying
the amino acid methionine, which matches the start codon, AUG). This setup, called the
initiation complex, is needed in order for translation to get started.
Draw a tRNA and indicate the anticodon region - correct answer ✔✔
Describe how a ribosome initiates translation - correct answer ✔✔The initiator tRNA interacts
with the start codon AUG of the mRNA and carries a formylated methionine (fMet).
fMet is inserted at the beginning (N terminus) of every polypeptide chain synthesized by E. coli.
In E. coli mRNA, a leader sequence upstream of the first AUG codon, called the Shine-Dalgarno
sequence (also known as the ribosomal binding site AGGAGG), interacts through
complementary base pairing with the rRNA molecules that compose the ribosome.
This interaction anchors the 30S ribosomal subunit at the correct location on the mRNA
template. At this point, the 50S ribosomal subunit then binds to the initiation complex, forming
an intact ribosome.
Describe how a polypeptide chain is formed - correct answer ✔✔Elongation is the stage where
the amino acid chain gets longer. In elongation, the mRNA is read one codon at a time, and the
amino acid matching each codon is added to a growing protein chain.
Each time a new codon is exposed:
A matching tRNA binds to the codon
answers passed
Describe the central dogma of molecular biology - correct answer ✔✔DNA → RNA → Proteins
The Central Dogma is the process by which the instructions in DNA are converted into a
functional product (the protein) with the intermediary of the RNA.
The central dogma of molecular biology explains the flow of genetic information, from DNA to
RNA to Proteins
DNA→ RNA = transcription
They are the same "language" of nucleic acids
RNA → Proteins = translated
They are not the same language so it needs to be translated to this new language
List the types of genetic elements found in bacteria - correct answer ✔✔Chromosomes
Circular thread like structures made of DNA molecules that contain genes.
Plasmids
genetic element that can replicate separately from the chromosome
Double stranded circular DNA (few are linear)
,few thousand to hundreds of thousand of base pairs
have a region called the origin of replication (replication proceeds bidirectionally)
replication requires RNA primer
have genes such as those for antibiotic resistance
genes for conjugation (pilus and enzymes)
Describe the basic structure of an operon - correct answer ✔✔Single transcription unit.
(multiple genes being transcribed together)
Promoter (starts)
Coding genes ORF (g1g2 etc)
Terminator (stops)
Describe how a change in a nucleotide propagates through the various steps of information
transfer, especially for frame shifts and changes in key features. - correct answer ✔✔If you
change a single nucleotide in the DNA, you change the RNA and then you change the protein
made. If this change causes the codon to change, the whole protein could be wrong, not work,
or not be functional
Arrange in order the following DNA features and how they correspond to mRNA and protein. -
correct answer ✔✔The promoter (35 and 10)
+1 of transcription
Shine Dalgarno sequence (RBS)
Start Codon
Operators
coding sequence
stop codon
transcriptional terminator
, Diagram an RNA molecule including sites needed for translation initiation and termination -
correct answer ✔✔In bacteria the small ribosomal subunit attaches directly to certain
sequences in the mRNA. These Shine-Dalgarno sequences come just before start codons and
"point them out" to the ribosome.
In initiation, the ribosome assembles around the mRNA to be read and the first tRNA (carrying
the amino acid methionine, which matches the start codon, AUG). This setup, called the
initiation complex, is needed in order for translation to get started.
Draw a tRNA and indicate the anticodon region - correct answer ✔✔
Describe how a ribosome initiates translation - correct answer ✔✔The initiator tRNA interacts
with the start codon AUG of the mRNA and carries a formylated methionine (fMet).
fMet is inserted at the beginning (N terminus) of every polypeptide chain synthesized by E. coli.
In E. coli mRNA, a leader sequence upstream of the first AUG codon, called the Shine-Dalgarno
sequence (also known as the ribosomal binding site AGGAGG), interacts through
complementary base pairing with the rRNA molecules that compose the ribosome.
This interaction anchors the 30S ribosomal subunit at the correct location on the mRNA
template. At this point, the 50S ribosomal subunit then binds to the initiation complex, forming
an intact ribosome.
Describe how a polypeptide chain is formed - correct answer ✔✔Elongation is the stage where
the amino acid chain gets longer. In elongation, the mRNA is read one codon at a time, and the
amino acid matching each codon is added to a growing protein chain.
Each time a new codon is exposed:
A matching tRNA binds to the codon
