1. DNA
By: Mr. Kauffman

2. Outline DNA background information Discovering DNA DNA structure
How DNA works
Storing DNA

3. DNA Background Information
DNA: Deoxyribonucleic Acid
DNA is the genetic/hereditary material found in all cells
Stored in the nucleus
Contains the information that determines what we look like

4. DNA Background Information
Contains the information to control a cell’s growth and function, but…
Only tells how to make things
Other parts (proteins) of the cells actually do the work

5. DNA Background Information
DNA Analogy
DNA is like a cookbook
It tells how to make something, but it doesn’t actually make it
Your DNA contains the instructions for how to make you

6. DNA Background Information
Every “normal” cell in your body has the same exact DNA in it
Skin and muscle cells are normal cells
When a cell divides, the DNA inside the cell is copied and each new cell gets 1 copy of it

7. Discovering DNA Scientists have known about DNA since the 1800’s 1952
Rosalind Franklin discovered that DNA was made up of 2 chains in a spiral shape
1953
James Watson and Francis Crick made a model of DNA

8. DNA Structure Known as a Double Helix
Meaning there are 2 sides in a spiral shape
More commonly called a twisted ladder

9. DNA Structure
Outer parts of the DNA ladder are called the sugar-phosphate backbone
Alternating sections of sugar and phosphate

10. DNA Structure
The rungs of the DNA ladder are made up of nitrogen bases
There are 4 types of nitrogen bases
1. Adenine (A)
2. Cytosine (C)
3. Guanine (G)
4. Thymine (T)
The bases are always found in pairs
Adenine (A) always pairs with Thymine (T)
Cytosine (C) always pairs with Guanine (G)
They fit together like puzzle pieces

11. DNA structure

12. DNA structure Draw the picture on the left in your notes
Provide the base that each base you have been given would pair with A G C T

13. How DNA works
The sequence of the DNA bases (A,C,G,T) determines the information contained in the DNA
A sequence of 3 bases is called a codon
ACGGCAATTGCTTTTAAGCCA
ACG , GCA , ATT , GCT , TTT, AAG , CCA

14. 20 Amino Acids Amino Acid DNA Codon Isoleucine ATT, ATC, ATA Serine
TCT, TCC, TCA, TCG, AGT, AGC
Leucine
CTT, CTC, CTA, CTG, TTA, TTG
Tyrosine
TAT, TAC
Valine
GTT, GTC, GTA, GTG
Tryptophan
TGG
Phenylalanine
TTT, TTC
Glutamine
CAA, CAG
Methionine
ATG
Asparagine
AAT, ACC
Cysteine
TGT, TGC
Histidine
CAT, CAC
Alanine
GCT, GCC, GCA, GCG
Glutamic Acid
GAA, GAG
Glycine
GGT, GGC, GGA, GGG
Aspartic Acid
GAT, GAC
Proline
CCT, CCC, CCA, CCG
Lysine
AAA, AAG
Threonine
ACT, ACC, ACA, ACG
Arginine
CGT, CGC, CGA, CGG, AGA, AGG

15. Storing DNA DNA is stored in the nucleus of the cell
Stored as chromosomes
How many chromosomes do humans have?
Every “normal” human cell has 46 single chromosomes, or 23 pairs of chromosomes
Each chromosome contains DNA with different information in it

16. Human Chromosome Chart
Storing DNA
Human Chromosome Chart

17. Actual Human Chromosomes
Storing DNA
Actual Human Chromosomes