2. DNA: The Genetic Material The instructions for inherited traits are called genes DNA: primary material that causes recognizable, inheritable characteristics in related groups of organisms

3. The Shape of DNA A DNA molecule looks like a spiral staircase and is composed of two parallel strands of linked subunits called nucleotides

4. The Shape of DNA A nucleotide has 3 parts: phosphate group, sugar (deoxyribose), and a base The phosphate and sugar link together to form the back bone The bases pair together to connect the two strands

5. DNA Replication Step 1: Unwind and Separate the DNA Strands – Two complementary strands of DNA separate from each other and form Y shapes called replication forks Step 2: Add Complementary Bases – At the replication fork, new nucleotides are added to each side according to the base-pairing rules Step 3: Formation of Two Identical DNA Molecules – Each double-stranded DNA helix is made of one new strand of DNA and one original strand of DNA

6. Base Pairing Rules

7. Replication Proteins DNA Helicase – enzyme that unwinds DNA DNA Polymerase – enzyme that adds nucleotides to each base to form two new double helixes; proofreads http://www.youtube.com/watch?v=zdDkiRw1PdU

8. Gene Expression The manifestation of genes into specific traits Two Steps: Transcription Translation

9. Transcription Location: nucleus Makes mRNA from DNA After mRNA is made it travels into the cytoplasm

10. Codon 3 letter code on mRNA Pairing rules with DNA – A – U (Uracil) – T – A – C - G

11. Translation Makes protein from mRNA in cytoplasm on a ribosome tRNA carries anticodons to codons which code for an amino acid rRNA helps to make protein

12. Translation

13. What amino acid does each codon represent? UUG GUA CAC ACU AGG CCG = Leucine = Valine = Histidine = Threonine = Arginine = Proline