2. AP Biology 2006-2007 Nucleic acids

3. AP Biology 2006-2007 Nucleic Acids

4. AP Biology proteins DNA Nucleic Acids  Function:  Stores all genetic material of an organism  In the form of genes  Provides the blueprint for building proteins DNA  RNA  proteins  transfers information  blueprint for new cells  blueprint for next generation

5. AP Biology A A A A T C G C G T G C T

6. Nucleic Acids  Examples:  RNA (ribonucleic acid)  3 forms serving different functions in building protiens:  mRNA – carries the blueprint to build proteins  tRNA – carries amino acid to build proteins  rRNA – assists the ribosome to build protein  DNA (deoxyribonucleic acid)  Spiraled double helix  Stores the organism’s entire genome (all genetic information) RNA DNA

7. AP Biology Nucleotides  Are the monomers of nucleic acids  Has 3 parts:  nitrogen base  5 (pentose) carbon sugar  Sugar in RNA is ribose  Sugar in DNA is deoxyribose  phosphate (PO 4 ) group

8. AP Biology 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) Purine = AG Pure silver!

9. AP Biology Nucleic polymer  Backbone  sugar to PO 4 bond  phosphodiester bond  new base added to sugar of previous base  polymer grows in one direction  N bases hang off the sugar-phosphate backbone

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

11. AP Biology DNA molecule  Double helix  H bonds between bases join the 2 strands  A :: T  C :: G

12. AP Biology double helix 1 st proposed as structure of DNA in 1953 by James Watson & Francis Crick