(46 pts) Answer True or False for each of the following questions. a) The most c
ID: 252998 • Letter: #
Question
(46 pts) Answer True or False for each of the following questions. a) The most commonly seen form of DNA double helix in the cell is the A form belix b) In E coli, the DNA double helix is a circular molecule that is twisted into a superhelix by the process of supercoiling c) In DNA replication, one of the two chains of each daughter DNA molecule is newly synthesized, and the other is from the parent DNA _ d) Bases stacked in a double helix absorb more UV light than bases in a single-stranded molecule. e) Many DNA polymerases have nuclease activity, allowing the removal of mismatched bases -f) Translation begins near promoter sites and ends at terminator sites. g) Prokaryotic mRNA undergoes postranslational processing, but there is no postranslational processing in eukaryotic mRNA h) The anticodon, consisting of three bases in transfer RNA, recognizes a complementary 3 base sequence in the mRNA called the codon. i) The geneti? code is overlapping and non-degenerate. j) The restriction enzymes recognize cleavage sites of 4 to 8 nucleotides in length that are palindromic. k) Fluorescence detection of oligonucleotide fragments produced by the dideoxy method requires radioactive labeling of the nucleotides DPCR cycles will amplify the target sequence (short strand) exponentially and the parent sequence (long strand) arithmetically m) If the concentration of salt in solution increases, the melting temperature of DNA decreases. n) As the percentage of the G-C base pairs increases, the melting temperature of DNA decreases o) In the lung, the presence of higher concentration of O, promotes the release of H and CO from hemoglobin. p) The affinity of hemoglobin for O, increases with increase of the CO2 concentration q) The oxidation state of Fe in the functional myoglobin is +3. r) The acidic environment of an exercising muscle makes hemoglobin bind to Oz more strongly s) A single amino acid substitution in the p-chain of hemoglobin causes sickle-cell anemia. ) Myoglobin is an allosteric protein, whereas hemoglobin is not. u) The affinity of hemoglobin for O, is regulated by an organic phosphate (2.3-BPG), whereas the affinity of myoglobin for O, is not v) In the lung, the presence of higher concentration of O, promotes the release of H and coExplanation / Answer
a. FALSE: The most common form, present in most DNA at neutral pH and physiological salt concentrations, is B-form.
In E.coli, the DNA helix is a circular molecule that is twisted into a superhelix by the process of supercoiling
b. FALSE: because, if the DNA making up a closed-circular molecule conforms closely to the B-form structure, with one turn of the double helix for each 10.5 base pairs, the DNA will be relaxed rather than supercoiled
In the DNA replication, one of the two chain of each daughter DNA molecule is newly synthesized, and the other is from the parent DNA.
c. TRUE: Because of Semiconservative method of replication.
Basic stacked in a double helix absorb more UV light than bases in a single stranded molecule.
d. False: Because, Double-strandedDNA absorbs less strongly than denatured DNA due to the stacking interactions between the bases.
Many DNA polymerases have nuclease activity, allowing the removal of mismatched bases
e. False: because, not many but Some of the DNA polymerases are provided with proofreading activities that allows the removal of misincorporated dNTP molecules by a 5? 3? exonuclease
Translation begins near promoter sites and ends at terminator sites
f. TRUE:
Prokaryotic mRNA undergoes posttranslational processing, but there is no posttranslational processing in eukaryotic mRNA
g. FALSE: mRNA undergoes posttranscriptional modification and not posttranslational modification
The anticodon , consisting of three bases in transfer RNA recognises a complimentary 3 bases sequence in the mRNA called the codon.
h. TRUE
The genetic code is overlapping and non degenerate
i. FALSE:
The restriction of recognizes cleavage site of 4 to 8 nucleotides in length that are palindromic.
j. FALSE: because, not all restriction enzymes cut at palindromic sequences. ... Recognising a palindromic sequence enables them to cut both strands of DNA at the "same" site, because the strand will have the same sequence only in different directions at that site.
Fluorescent detection of oligonucleotides fragments produced by the dideoxymethod requires radioactive labeling of the nucleotides
k. TRUE
PCR cycles will amplify the targets sequences ( short strand) exponentially and the parent sequence( long strand) arithmetically
l. FALSE
If the concentration of salt solution increases, the melting temperature of DNA decreases.
m. False: because, The melting temperature also depends on the salt concentration: in low salt, a given DNA will melt at a lower temperature than in a higher salt concentration. This is because DNA is a polyanionic molecule. The salt "shields" the negative charges on each phosphate.
As the percentage of G-C base pair increases the melting temperature of DNA decreases
n. False: because as the G-C base pair increases the melting temperature of DNA increases
In the lung the presence of higher concentrationof O2 promotes the release of H+ and CO2 from heamoglobin
The affinity heamoglobin for O2 increases with increase of the CO2 concentration.
p. False. Because the High concentrations of CO2 stabililze the T state, which decreases the oxygen affinity of hemoglobin.
The oxidation state of Fe in the myoglobin is +3
q. False: Because the oxidation state of Fe in the myoglobin is +2
The acidic environment of an excersing mussle makes heamoglobin bind to O2 more strongly
r. FALSE. Because the lowered pH (more acidic environment) decreases hemoglobin’s affinity for oxygen.
A single amino acid substitution in the Beta chain of hemoglobin causes sickle cell anemia.
s. TRUE: Because, Sickle cell anemia is caused by a single amino acid substitution at the 6th amino acid residue in the beta chains of hemoglobin where in a glutamate is replaced by a valine due to a point mutation in the beta globin gene
Myoglobin is an allosteric protein whereas hemoglobin is not
t. False: Because the hemoglobin is an allosteric protein whereas the myoglobin is not
u. TRUE. The affinity of hemoglobin for O2 is regulated by an organic phosphate (2-3 BPG) whereas the affinity of myoglobin for O2 is not
v. TRUE. In the lung the presence of higher concentration of O2 promotes the release of H+ and CO2
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.