1. DNA in the Genomic era

2. Review of Chapter 12
Each group will focus on particular scientists. Take about minutes to review the experiment(s) and conclusion(s) before presenting to the class.
Molly & Tulip – Hammerling; Briggs & King
Dali & Sarah – Griffith; Avery
Gabriel & Cody – Hershey & Chase
Tela & Xander - Fraenkel-Conrat
Chris & Nathan – Chargaff; Wilkins; Franklin
James & Nathalie – Watson & Crick
Sam & Griffin– Meselson & Stahl
Jacob & Katie – Beadle & Tatum

3. DNA
Deoxyribonucleic acid (DNA) is a macromolecule in the nucleic acid group.
Contains the genetic information for the development and function of an organism

4. Nucleotides Monomers of DNA Each Nucleotide has 3 parts
Phosphate group
Sugar (Deoxyribose)
Nitrogenous Base

5. Nucleotides (cont) 4 different DNA bases: A, T, C, G Purines: A and G
Pyrimidines: C and T

6. Nucleotide Bonding
What type of reaction connects the phosphate group from one nucleotide to the sugar group from another nucleotide?
What’s wrong with the diagram?

7. Base Pairing
What type of bonds connect the bases? Why is it advantageous to have this type of bond?

8. Genes
Gene - section of DNA that contains the information to make a specific protein/ polypeptide.
In other words…..
A gene is a set of instructions for making a protein
Proteins have specific sequences of amino acids
Hemoglobin - carries oxygen
Actin and myosin - make up muscles
Polymerase - replicates DNA

9. Gene Expression Steps to Gene Expression
What is transcription?
What is translation?
Process by which a cell uses genetic information
Not all genes are expressed all the time
Ex. Hemoglobin gene is expressed in red blood cells but not in nerve cells

10. Transcription Process of converting the DNA code into an RNA code
Why….?
DNA is stuck in the nucleus
RNA carries the message to the ribosomes

11. RNA Ribonucleic acid Almost structurally identical to DNA 3 types
Ribose sugar rather than deoxyribose
Single strand rather than double strand (mostly!)
3 types
Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)

12. RNA (cont) 4 RNA nucleotides. Base Pairing still occurs Guanine (G)
Cytosine (C )
Adenine (A)
Uracil (U) - replaces thymine
Base Pairing still occurs
G to C
A to U

13. Transcription
Very similar to DNA replication except a single strand of mRNA is produced.
RNA polymerase - enzyme responsible for connecting RNA bases together
DNA message is “transcribed” to mRNA

14. Introns and Exons
Introns - sections of mRNA transcripts that are removed before translation begins
Exons - sections of mRNA that is kept.

15. Translation
Process of converting the mRNA code into a specific sequence of amino acids
Also called, Protein synthesis
Ribosomes - cellular structures that “read” the mRNA code
tRNA - molecules that carry amino acids to the ribosomes

16. The Genetic Code Three mRNA bases identify each amino acid.
Ex. AUG equals the amino acid methionine
Codon - name for each three mRNA nucleotide sequence

18. 2nd codon letter
1st codon letter
20 different Amino Acid
3rd codon letter

19. Central Dogma of Biology
Genotype: DNA
Messenger: mRNA
Phenotype: Protein
Transcription
Translation (Protein synthesis)
regulation
Replication
Trait