1. What Does DNA Look Like?
Chapter 6: Section 1

2. DNA
- Deoxyribonucleic Acid
- Genetic material
- Determines inherited traits
Nucleotides
- Subunits of DNA
- Made from sugar, phosphate, and a base

3. Erwin Chargaff
- Amount of Adenine always equals amount of Thymine
- Amount of Guanine always equals amount of Cytosine
- Chargaff’s Rule
- A paired with T
- C paired with G
- Took images of DNA
Rosalind Franklin
- Used X-Ray Diffraction

4. - Used work of Franklin and Chargaff
Watson and Crick
- Devised model of DNA
- Model looked like a twisted ladder
- Model helped explain functions of DNA
Double Helix
- Shape of DNA strand
- Sides alternate between phosphate and sugar
- Rungs of ladder are the pairs of bases

6. Making Copies of DNA Replication - Making a copy
- DNA molecule split down the middle
- Bases are used as a pattern
- New strand contains part old and part new
- Complete copies of DNA are made every time the cell divides
- New cell receives full copy of DNA

9. Unraveling DNA - DNA is wrapped around proteins - Coiled into strands
- Forms chromosomes
Gene
Contains information for specific traits
- A specific section of DNA that contains a code for a protein
Proteins
Helps chemical reactions to occur
- Large molecules made up of chains of amino acid
- 20 different amino acids that combine into thousands of different proteins
Help determine traits

10. Unraveling DNA Nucleus DNA codes for proteins which determine traits
DNA is made of chromatin which is bundled
loosely
A single strand of chromatin is made up of
a long strand of DNA wrapped around protein
Each DNA strand contains 2 halves 
connected in the middle and twisted 
double helix
Cell Division
Chromatin is packaged into chromatids
2 identical chromatid chromosome
Chromosome is ready to divide

12. - Ribonucleic Acid, is a single strand
RNA
- Ribonucleic Acid, is a single strand
- Helps DNA make proteins
- Similar to DNA
- Acts as a temporary copy of DNA
-Copies the information from the DNA inside the nucleus then travels outside of the cytoplasm
mRNA
- Messenger RNA, carries the message or code outside of the nucleus
- The copy of DNA
- Made of RNA and proteins
Ribosome
- Uses mRNA, tRNA, and Amino Acids
- Makes proteins

13. - Transfer RNA
tRNA
- Brings Amino Acids to ribosome
- Shaped like a T
- Fits into specific codon

14. Codon –
A triplet sequence of DNA or RNA

15. Making a Protein Copy one side of DNA-only genes are copied
- mRNA is the copy moves out of nucleus into
cytoplasm
- mRNA is fed through the ribosome 3 bases at a
time
- tRNA translates the RNA message
- Each tRNA picks up a specific amino acid in
cytoplasm
- In the ribosome, bases of tRNA are paired
with bases of mRNA
- tRNA releases amino acids linked in growing
chain
- Entire mRNA passes through ribosome 
amino acid chain folds up into new protein

19. Changes in Genes Mutation - Change in DNA sequence
- Changes in number, type, or order of bases
- Mutations occur during DNA replication
- Random errors
Mutagen
- Physical or chemical agent that causes a mutation
3 Types of Consequences
1. Improved Trait
2. No Change
3. Harmful Trait

20. 3 Types of Mutations
1. Replacement
2. Addition
3. Deletion

21. - Caused by a substitution-valine for glutamic acid
Sickle Cell Anemia
- Mutation causes the wrong protein to be made
- Red blood cell changes shape and cannot carry
oxygen well

22. - Scientists can change an organism’s genes
Genetic Engineering
- Can manipulate desired changes
- Everyone’s DNA is unique
DNA Fingerprinting
- It can used to identify you
- Identifies unique pattern’s in DNA
- DNA sequences can act like a fingerprint