1. DNA & RNA Replication & Transcription Central Dogma: DNA—RNA--Protein

2. Review DNA What are some of the characteristics of DNA? (Think about structure and function)

3. DNA What makes up the code in DNA? If there is 40% Adenine, how much Guanine is present? Compare and contrast hydrogen and covalent bonding in a DNA molecule. Strands in opposite direction (anti- parallel)

4. DNA Replication What is the end result? Identical copies of DNA Mitosis

5. DNA Replication Occurs in the nucleus Copies chromosomes After “un-zipping”, strand serves as a template Final result=1 new strand: 1 original

6. DNA Replication

7. Role of enzymes: Helicase: breaks Hydrogen-bonds (H-bonds) DNA Polymerase: attaches free nucleotides

8. RNA Why do we need RNA? DNA is trapped in the nucleus Where are proteins made? The ribosomes mRNA is literally a messenger How do we make mRNA? Compare and contrast DNA & RNA

10. DNA & RNA DNA Nucleotides (phosphate, deoxyribose, nitrogen bases) Adenine Guanine Cytosine Thymine Double Stranded(double helix) RNA Nucleotides (phosphate, ribose, nitrogen bases) Adenine Guanine Cytosine Uracil (Thymine gone) Single Stranded

12. Transcription The process of making RNA using DNA as a template How much of the DNA molecule is utilized? Only a part Occurs in the nucleus Makes RNA

13. Transcription RNA polymerase bonds free nucleotides. Creates a RNA molecule with free nucleotides (No Thymine..Uracil) 3 types: mRNA: messenger (This will later be translated into a polypeptide.) rRNA: ribosomal (This will be used in the building of ribosomes: machinery for synthesizing proteins by translating mRNA.) tRNA: transfer (RNA molecules that carry amino acids to the growing polypeptide.)

14. Transcription continued… RNA polymerase is used Start and stop signals on the DNA strand Complimentary base pairing A-U & G-C A T T G C C A T U A A C G G U A

15. Genetic Code mRNA has a nucleotide sequence, taken from DNA strand mRNA carrying a genetic message Determines order of amino acids…which make up your proteins!!! The genetic code consists of 64 triplets of nucleotides. These triplets are called codons on mRNA. Each codon encodes for one of the 20 amino acids used in the synthesis of proteins 3 exceptions: UAA, UAG, UGA = STOP Start codon=methionine….AUG

16. More Genetic Code