BIOMG 3300 - Unit 8 Questions with Correct Answers
What is the minimum number of nucleotides per amino acid required to
specify all 20 amino acids? Correct Answer-3 nucleotide bases per
amino acid
Codon Correct Answer-a triplet of nucleotides that codes for a specific
amino acid
Translation occurs in such a way that these nucleotide triplets are read in
a successive, nonoverlapping
the key to the translation of genetic information, directing the synthesis
of specific proteins
Overlapping Correct Answer-AUACGAGUC -> is read like AUA,
UAC...
Non-overlapping Correct Answer-AUACGAGUC -> is read like AUA,
CGA...
Reading frame Correct Answer-A contiguous, nonoverlapping set of
three-nucleotide codons in DNA or RNA
a new codon begins every three nucleotide residues
,Are individual codewords delimited, as for example words in a sentence
are delimited by spaceAre individual codewords delimited, as for
example words in a sentence are delimited by spaces? Correct Answer-
NO
There is no punctuation between codons for successive amino acid
residues. The amino acid sequence of a protein is defined by a linear
sequence of contiguous triplets
What establishes the reading frame in RNA? Correct Answer-The
reading frame is set when translation of an mRNA molecule begins, and
it is maintained as the synthetic machinery reads sequentially from one
triplet to the next
If the initial reading frame is off by one or two bases, or if translation
somehow skips a nucleotide in the mRNA, all the subsequent codons
will be out of register resulting into a "missense" protein with a garbled
amino acid sequence
What are the expected consequences of a one or two base addition or
deletion within the above sequence? Correct Answer-- Inserting or
deleting one base pair alters the sequence of triplets in a non-overlapping
code
- all amino acids coded by the mRNA following the change are affected
- Combining insertion and deletion mutations affects some amino acids
but can eventually restore the correct amino acid sequence
- Adding or subtracting three nucleotides leaves the remaining triplets
intact
, Why are such additions or deletions (when they occur in the DNA)
called frameshift mutations? Correct Answer-A programmed change in
the reading frame during translation of an mRNA on a ribosome
a mechanism either to allow two or more related but distinct proteins to
be produced from a single transcript or to regulate the synthesis of a
protein
Example: The reading frame for pol is offset to the left by one base pair
(−1 reading frame) relative to the reading frame for gag
Initiation codon Correct Answer-AUG is the most common signal for
the beginning of a polypeptide in all cells - the coding for Met residues
in internal positions of polypeptides
Termination codon Correct Answer-stop codons or nonsense codons,
normally signal the end of polypeptide synthesis and do not code for any
known amino acids
There are 3 stop codons - UAA, UAG, and UGA
Open reading frame Correct Answer-a reading frame without a
termination codon among 50 or more consecutive codons
What is the minimum number of nucleotides per amino acid required to
specify all 20 amino acids? Correct Answer-3 nucleotide bases per
amino acid
Codon Correct Answer-a triplet of nucleotides that codes for a specific
amino acid
Translation occurs in such a way that these nucleotide triplets are read in
a successive, nonoverlapping
the key to the translation of genetic information, directing the synthesis
of specific proteins
Overlapping Correct Answer-AUACGAGUC -> is read like AUA,
UAC...
Non-overlapping Correct Answer-AUACGAGUC -> is read like AUA,
CGA...
Reading frame Correct Answer-A contiguous, nonoverlapping set of
three-nucleotide codons in DNA or RNA
a new codon begins every three nucleotide residues
,Are individual codewords delimited, as for example words in a sentence
are delimited by spaceAre individual codewords delimited, as for
example words in a sentence are delimited by spaces? Correct Answer-
NO
There is no punctuation between codons for successive amino acid
residues. The amino acid sequence of a protein is defined by a linear
sequence of contiguous triplets
What establishes the reading frame in RNA? Correct Answer-The
reading frame is set when translation of an mRNA molecule begins, and
it is maintained as the synthetic machinery reads sequentially from one
triplet to the next
If the initial reading frame is off by one or two bases, or if translation
somehow skips a nucleotide in the mRNA, all the subsequent codons
will be out of register resulting into a "missense" protein with a garbled
amino acid sequence
What are the expected consequences of a one or two base addition or
deletion within the above sequence? Correct Answer-- Inserting or
deleting one base pair alters the sequence of triplets in a non-overlapping
code
- all amino acids coded by the mRNA following the change are affected
- Combining insertion and deletion mutations affects some amino acids
but can eventually restore the correct amino acid sequence
- Adding or subtracting three nucleotides leaves the remaining triplets
intact
, Why are such additions or deletions (when they occur in the DNA)
called frameshift mutations? Correct Answer-A programmed change in
the reading frame during translation of an mRNA on a ribosome
a mechanism either to allow two or more related but distinct proteins to
be produced from a single transcript or to regulate the synthesis of a
protein
Example: The reading frame for pol is offset to the left by one base pair
(−1 reading frame) relative to the reading frame for gag
Initiation codon Correct Answer-AUG is the most common signal for
the beginning of a polypeptide in all cells - the coding for Met residues
in internal positions of polypeptides
Termination codon Correct Answer-stop codons or nonsense codons,
normally signal the end of polypeptide synthesis and do not code for any
known amino acids
There are 3 stop codons - UAA, UAG, and UGA
Open reading frame Correct Answer-a reading frame without a
termination codon among 50 or more consecutive codons
