9'6 Are the following nucleotide sequences DNA or RNA and are they

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9.6 Are the following nucleotide sequences DNA or
RNA and are they single or double
stranded? molecule A G T C U a. 33 17 33 17
0 double strand DNA b. 33 33 17 17 0 single
strand DNA c. 26 24 0 24 26 double strand
RNA d. 21 40 21 18 0 single strand
DNA e. 15 40 0 30 15 single strand RNA f.
30 20 15 20 15 DNA RNA duplex
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9.8 5 DNA molecules (assume equal length) melt
at 73, 69, 84, 78, 82 oC. Arrange these in
increasing percentage of GC content. AT base
pairs are weaker than GC base pairs and therefore
melt sooner therefore 69, 73, 78, 82, 84 oC
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9.12 What would the Meselson and Stahl experiment
have shown if DNA replication was a) conservative
and b) dispersive. A. Conservative replication
would maintain a double strand of parental DNA
and a new double stranded daughter DNA. This
would give one full heavy band and one light band
after 1 division. After 2 divisions, the light
DNA band would be 3x (one 1st replication, 2 2nd)
with 1 heavy. B. Dispersive replication is any
kind of mixture of the other models. This model
would have the heavy band move to a medium
intensity band after 1 division, and go to a
somewhat lighter band after 2 divisons (staying 1
band), a somewhat lighter yet band after 3
divisions, etc). Or instead staying as a single
band, it could go to a very diffuse band (ie.
spread out over many different densities).
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9.14 Given the DNA strand below, what DNA
sequence would convert this into a double helix
(ie. normal DNA). What would the primase
RNA bases look like if this segment initiated an
Okazaki fragment? In which direction does
replication proceed? 5'-ATTCTTGGCATTCGC-3' dna
5'-GCGAATGCCAAGAAT-3' rna 5'-GCGAAUGCCAAGAAU-3'
the polymerase will move from the 5' to 3'
direction ie. to the left
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9.18 Describe the enzymology of the origin,
continuation, and termination of DNA replication
in E. coli. DNA replication starts at the origin
and proceeds in both directions as the strands
separate. Single stranded binding protein
stabilizes the single stranded DNA while DNA
helicases unwind the DNA at the replication forks
and DNA gyrase relieves the tension by cleaving
the DNA and untwisting it in the reverse
direction. RNA polymerase then sets down a short
RNA primer in the 5' to 3' direction. DNA
polymerase III then adds nucleotides in both
directions in the 5' to 3' direction along the
leading strand of DNA (one for each replication
fork). Once replication has proceeded for a
length along the one strand, a new RNA
polymerase binds on the single stranded DNA near
the replication fork and initiates DNA
replication along the lagging strand in the 5' to
3' direction until it fills in nucleotides to the
next bound nucleotide, called an
Okazaki fragment. DNA polymerase I removes the
RNA primers and replaces them with DNA, then DNA
ligase seals the single stranded nicks between
the Okazaki fragments.