1. Why do we study DNA?
DNA is the
blueprint
for life

2. The Central Dogma of Molecular Biology
Genes code  protein  perform functions in the cell that results in a phenotype
DNA  RNA  Protein
Transcription
Translation

3. Example of Phenotypes Created by Proteins
Hair color
Eye color
Hair texture
Blood type (A, B, O)
Shoe size
Eyelash length

4. How much DNA is in our body?
Our DNA makes up 1% of our body weight, so a 150 lb. person would have 1.5 lbs. of DNA.
In one cell – 3 meters of DNA.
If you typed out your entire DNA sequence in Times 12pt font you would fill enough paper to reach the top of the Washington Monument in D.C.

5. How the Cell Stores DNA Double helix Nucleosomes DNA and histones
Folds long strands of DNA
Regulates what is expressed
Chromatin – Packed DNA and histones (type of protein)
Supercoils
Chromosomes – most tightly packaged DNA
Packaging Movie

6. I supercoiled myself into this box!

7. Chromosome Numbers
Humans: 46
Mouse: 40
Dog: 78
Corn: 20
Ant: 2

8. The Structure of DNA Nucleotides
DNA: DeoxyriboNucleic Acid
Found in the nucleus
Three subunits for each building block:
Deoxyribose (5 carbon sugar)
Phosphate
Nitrogen Base (can be 1 of 4)
Guanine
Cytosine
Adenine
Thymine

9. Base Pair Matching
The two strands are held together by hydrogen bonds.
G and C – form 3 hydrogen bonds
A and T – form 2 hydrogen bonds
DNAtris

10. DNA Game
The Double Helix
James Watson, Francis Crick, and Maurice Wilkins were awarded the Nobel prize.
Rosalie Franklin died before she could be awarded with the Nobel prize.
Chargraff identified that G and C pair, and T and A pair.

11. DNA Replication Double helix must unzip
H-bonds break
Each original strand becomes a template strand (white)
Bases fill in to form Complementary strands (black)
DNA polymerase – building enzyme – adds new bases
Occurs in the nucleus

12. fills in new nucleotide bases
DNA Replication
A-T
T-A
C-G
G-C A- T- C- G- -T -A -G -C
Enzyme
(Helicase) Unzips
DNA Workshop A- T- C- G- -T -A -G -C
T A A G C
A T T C G
Enzyme
(DNA Polymerase)
fills in new nucleotide bases
New Strands

13. RNA Structure RNA: RiboNucleic Acid Found in the nucleus (nucleolus)
Can leave the nucleus
Single stranded!
Building blocks made of:
Ribose (5 carbon sugar)
Phosphate
Nitrogen Base (1 of 4)
Guanine
Cytosine
Adenine
Uracil (Instead of Thymine)

14. Three Kinds of RNA Messenger RNA (mRNA)
conveys genetic information to the rest of the cell
Ribosomal RNA (rRNA)
structural, part of ribosome
Transfer RNA (tRNA)
carries amino acids to site of protein synthesis

15. Transcription Occurs in the nucleus
Animation
Transcription
Occurs in the nucleus
RNA polymerase adds complementary nucleotides
Forms from one of the DNA strands (template strand)
RNA is a blue print for proteins

16. fills in new nucleotide bases
DNA Workshop
Transcription A- T- C- G-
A-T
T-A
C-G
G-C -T -A -G -C
Enzyme
Unzips
Template Strand
U A A G C
Enzyme
(RNA Polymerase)
fills in new nucleotide bases
RNA Strand

17. ATGTCGGACTCAGAAGTCAATCAAGAAGCTAAGCCAGAGGTCAAGCCAGAAGTCAAGCCTGAGACTCACATCAATTTAAAGGTGTCCGATGGATCTTCAGAGATCTTCTTCAAGATCAAAAAGACCACTCCTTTAAGAAGGCTGATGGAAGCGTTCGCTAAAAGACAGGGTAAGGAAATGGACTCCTAAGATTCTTGTACGACGGTATTAGAATTCAAGCTGATCAGACCCCTGAAGATTTGGACATGGAGGATAACGATATTATTGAGGCTCACAGAGAACAGATTGGTGGTGCTACGTATTAG
Not all of this DNA sequence will make a protein, some of it is nonsense and some of it gives information about when the protein should be made.

18. The Genetic Code DNA is a code to make proteins Proteins:
Made by Amino Acids
There are 20 types of amino acids
Each amino acid has it’s own special character.

20. Translation: mRNA to Protein
Firefly
Movie
Think of each base as a letter (G, C, A, U)
Three bases = “a word”
Each “word” codes for an amino acid - codon
Start codon - AUG
Stop codons
Many codons together make a gene
Where does each step take place?

21. Forming Polypeptide Chain
Translation
Forming Polypeptide Chain
Lysine
tRNA
mRNA
Ribosome
Location: ribosomes
mRNA has codons (3 bases)
tRNA carries an amino acid to the forming polypeptide (3 bases on tRNA - anti-codon)
The anti-codons complement the codons in the mRNA
Begins at start codons
Ends at stop codons
Codon

22. Translation Animation

23. TAC GGC TAT CCA

24. What Do Mutations Cause?
What Causes Mutations?
Carcinogens
Radiation
Viruses
Heredity
What Do Mutations Cause?
Cancer
Slight frequent changes = polymorphisms
Genetic Diseases
Cystic fibrosis (effects mucus production)
Hemophilia (blood won’t clot)
Sickle cell anemia

25. Mutations Point mutations (Substitutions)
Original: The fat cat ate the wee rat.
Point Mutation: The fat hat ate the wee rat.
Frameshift mutations (Insertion, Deletion)
Original: The fat cat ate the wee rat.
Frame Shift: The fat caa tet hew eer at.
Deletion
Substitution
Insertion

26. Gene Regulation Not all genes are expressed in every cell
Not all genes are expressed at the same time.
An operon is a group of genes that operate together
A skin cell expresses different genes than a nerve cell
Regulatory sites
DNA strand
Promoter
Stop transcription
Start transcription

27. Chapter Objectives
Know the scientists involved with the discovery of the structure and function of DNA
Know the structure and function of DNA.
Know how DNA is packaged in the cell.
Know how DNA is replicated.
Know the structure and function of RNA.
Know how RNA is made.
Know the three types of RNA.
Know how RNA makes proteins.
Be able to go from a sequence of DNA to RNA to protein.
Give examples of types of proteins and what they do.
Differentiate between replication, transcription and translation.
List, demonstrate, and identify types of mutations.
Be able to discuss the potential outcomes of mutations.