Download Relationships between Structure and Function of the DNA _AP_

Relationships between
Structure and Function
of the DNA
Structure of the DNA
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Two antiparallel strands,
containing Deoxyribose
Joined by complementary bases (A,T, C, G)
Hydrogen bonds allow for easy separation of the
two strands. (A-T the easiest to separate)
Complementary bases and hydrogen bond allow for
the easy reunification of the two strands.
Chemical structures of the deoxyriboses,
phosphates and bases created an asymmetrical
helix, with a small groove and a big groove.
The helix structure allows for topological
manipulation.
Supercoiling of the DNA
molecule in the chromosome
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Supercoiling:
coiling of a double
helix in which
neither strand has
a free end or any
breaks.
It causes the
double helix to
cross over its own
axis.
DNA Replication is
Semiconservative
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Separation of the
parental strands of DNA.
Each strand acts as a
template for the
synthesis of new DNA
The sequences of the
daughter strand is
determined by
complementary base
pairing with the parental
strands
The Meselson-Stahl
Experiment
Nucleic acids hybridize by base
pairing
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Heating causes the two strands of DNA to separate
(denaturation)
The denaturation temperature depends on the
proportion of C-G base pairs in the DNA.
Complementary single strands renature when the
temperature is reduced
Denaturation, Renaturation and hybridization can
happen with DNA-DNA, DNA-RNA, and RNA-RNA.
They can be intermolecular or intramolecular.
The ability of two stranded single nucleic acids is a
measure of their complementarity.
The structure of DNA allows for
many manipulations
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The helix structure allows the cell to
“choose” the spot to separate two strands of
DNA.
The base pair sequence has “weakened”
points which can denaturate easily.
DNA can combine with other DNA, RNA.
RNA can also combine with other RNA in
special circumstances (tRNA)
DNA can combine within its own molecule.