1. Nucleic Acids
Information storage

2. Nucleic Acids Function: Examples: Structure:
store & transmit hereditary information
Examples:
RNA (ribonucleic acid)
DNA (deoxyribonucleic acid)
Structure:
monomers = nucleotides

3. Are nucleic acids charged molecules?
Nucleotides
3 parts
nitrogen base (C-N ring)
pentose sugar (5C)
ribose in RNA
deoxyribose in DNA
phosphate (PO4) group
DNA & RNA are negatively charged:
Don’t cross membranes.
Contain DNA within nucleus
Need help transporting mRNA across nuclear envelope.
Also use this property in gel electrophoresis.
Are nucleic acids charged molecules?

4. Dangling bases? Why is this important?
Nucleic polymer
Backbone
sugar to -PO4 bond
phosphodiester bond
new base added to sugar of previous base
polymer grows in one direction
N bases hang off the sugar-phosphate backbone
Dangling bases? Why is this important?

5. Pairing of nucleotides
Nucleotides bond between DNA strands
H bonds
purine :: pyrimidine
A :: T
2 H bonds
G :: C
3 H bonds
The 2 strands are complementary.
One becomes the template of the other & each can be a template to recreate the whole molecule.
Matching bases? Why is this important?

6. Passing on information? Why is this important?
Information polymer
Function
series of bases encodes information
like the letters of a book
stored information is passed from parent to offspring
need to copy accurately
stored information = genes
genetic information
All other biomolecules we spoke about served physical or chemical functions. DNA & RNA are information storage molecules.
DNA well-suited for an information storage molecule:
chemically stable
stores information in the varying sequence of nucleotides (the genetic code)
its coded sequence can be copied exactly by the synthesis of complementary strands; easily unzipped & re-zipped without damage (weak H bonds)
damage to one strand can be repaired by addition of bases that match the complementary strand
Passing on information? Why is this important?

7. Interesting note… Ratio of A-T::G-C affects stability of DNA molecule
2 H bonds vs. 3 H bonds
biotech procedures
more G-C = need higher T° to separate strands
high T° organisms
many G-C
parasites
many A-T (don’t know why)
At the foundation of biology is chemistry!!

8. Another interesting note…
ATP Adenosine triphosphate
modified nucleotide
adenine (AMP) + Pi + Pi + +

9. Let’s build some DNA, baby!