Nucleic acids:
Information molecules
Regents Biology
2006-2007
Nucleic Acids
Examples

DNA
 DeoxyriboNucleic
Acid

RNA
 RiboNucleic Acid
Regents Biology
RNA
Nucleic Acids
 Function:

genetic material
 stores information
 genes
 blueprint for building proteins

DNA
DNA  RNA  proteins
 transfers information
 blueprint for new cells
 blueprint for next generation
Regentsproteins
Biology
Genes (DNA)
are needed
to run bodies every day…
to make you and me…
to make new cells…
to make babies!
G
C
T
A
Regents Biology
A
C
G
T
A
C
G
T
A
Nucleic acids
 Building block = nucleotides
nucleotide – nucleotide – nucleotide – nucleotide

5 different nucleotides


different nitrogen bases
A, T, C, G, U
sugar
phosphate
Regents Biology
N base
Nitrogen bases
I’m the
A,T,C,G or U
part!
Nucleotide chains
 Nucleic acids

N base
sugar
N base
phosphate
nucleotides chained
into a polymer
 DNA
phosphate
 double-sided
 double helix
 A, C, G, T
strong bonds
 RNA
sugar
N base
sugar
N base
phosphate
 single-sided
 A, C, G, U
phosphate
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sugar
RNA
DNA
 Double strand twists into a double helix
weak bonds between nitrogen bases join
the 2 strands
 A pairs with T
 A :: T
weak bonds
 C pairs with G
 C :: G
 the two strands can
separate when our
cells need to make
copies of it

Regents Biology
Copying DNA
 Replication
copy DNA
 2 strands of DNA helix are
complementary

 they are matching
 have one, can build other
 have one, can rebuild the whole
Regents Biology
DNA replication
 Copying DNA

pairing of the bases
allows each strand to
serve as a pattern for
a new strand
Newly copied
strands of DNA
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1953 | 1962
Watson and Crick … and others…
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HELIXHELIX
Let’s build some
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DNA!