2. AP Biology Nucleic Acids Information storage

3. proteins DNA Nucleic Acids  Function:  genetic material  stores information  genes  blueprint for building proteins DNA  RNA  proteins  transfers information  blueprint for new cells  blueprint for next generation

4. A A A A T C G C G T G C T

5. Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)  double helix  Structure:  monomers = nucleotides RNADNA

6. Nucleotides  3 parts  nitrogen base (C-N ring)  pentose sugar (5C)  ribose in RNA  deoxyribose in DNA  phosphate (PO 4 ) group Nitrogen base I’m the A,T,C,G or U part!

7. Types of nucleotides  2 types of nucleotides  different nitrogen bases  purines  double ring N base  adenine (A)  guanine (G)  pyrimidines  single ring N base  cytosine (C)  thymine (T)  uracil (U)

8. Nucleic polymer  Backbone  sugar to phosphate group (PO 4 ) bond  phosphodiester bond  strong covalent bonds between a phosphate group and 2 pentose sugars  Formed by dehydration synthesis reaction  Allows the polymer to grow in one direction  N bases hang off the sugar-phosphate backbone

9. Pairing of nucleotides  Nucleotides bond between DNA strands  H bonds  purine :: pyrimidine  A :: T  2 H bonds  G :: C  3 H bonds

10. DNA molecule  Double helix  Hydrogen bonds between nitrogenous bases join the 2 strands  A :: T  C :: G  Significance of H Bonds:  Weak (easily broken)  Thus, they are susceptible to enzymes in both building and breaking bonds.  The DNA molecule itself is negatively charged…this will come up later.

11. Directionality  Anti-Parallel  Flip flopped arrangement  The numbered carbon atoms in the nucleotide sugar- ring gives rise to a 5'-end and a 3'-end (pronounced "five prime end" and "three prime end").

12. Interesting note…  ATP Adenosine triphosphate ++  modified nucleotide  adenine (AMP) + P i + P i