1. DNA

2. DNA Functions
Stores genetic information to build and maintain a living organism
Copies itself

3. James Watson & Francis Crick 1953
Determined the three-dimensional structure of DNA
One of the greatest discoveries in the history of science
Nobel prize in 1962

4. Rosalind Franklin
X-ray diffraction (x-rays bounce of atoms in DNA to make an image) images of DNA
Which led to the discovery of the DNA double helix.
By Watson and Crick

5. The Cell
The “nucleus” (one of many organelles) contains genetic information the cell needs to exist and reproduce
- most cells organize genetic information into chromosomes

6. Chromosomes
our body’s way of organizing all the information that our genetic material contains
23 pairs in humans
- each pair contains one from mother and one from father

7. Genes
Each chromosome contains 100s to 1000s of information blocks called genes
Each gene is the blueprint for a specific protein in the body
- may tell our body what color our eyes are supposed to be, dozens of proteins are responsible for synthesis of ATP, digesting food, etc, etc etc

8. DNA Made of repeating units called nucleotides
Each nucleotide made of a sugar (deoxyribose), a phosphate and a Nitrogen base
The sequence of nucleotides carries the genetic information of an organism
DNA is shaped in a double helix.

9. = DNA Nucleotide Phosphate Nitrogen Base Pairs:
Deoxyribose
Phosphate
Nitrogen Base
Nitrogen Base Pairs:
Adenine pairs with Thymine
Guanine pairs with Cytosine

10. Nucleotides Form a Double Strand -The sequence of nucleotides carries the genetic information of an organism
Deoxyribose
Phosphate
Base

11. DNA Molecule is Double Stranded

12. Base Pairing Rule Adenine pairs with Thymine
Guanine pairs with Cytosine
The order of nitrogen bases along a gene forms a genetic code that specifies what protein is produced

13. DNA Total length of DNA in each cell is about 6 feet
Wraps around proteins called histones
Over 3 billion nucleotide pairs in human DNA!

14. DNA Replication DNA nucleotides attach to each strand
DNA strands separate
DNA nucleotides attach to
each strand

15. First, DNA strands separate by an enzyme called DNA helicase

16. Second, An enzyme called DNA Polymerase adds paired bases to “single stranded” - A with T - C with G

17. Third, the strands finally detaches and each new DNA molecule will be an exact copy of the original

18. The Role of RNA Protein replication takes place outside of nucleus
A messenger (RNA) must carry the code from the nucleus to the cytoplasm
RNA: has only a single strand and contains different sugars than DNA and nitrogen bases
Nitrogen Bases:
Adenine pairs with Uracil
Guanine pairs with Cytosine

19. Types of RNA
Messenger RNA (mRNA): copies the message from the DNA inside the nucleus and carries the message to the ribosome in the cytoplasm
Transfer RNA (tRNA): carries amino acids to the ribosomes and adds them to the growing protein.

20. DNA Errors Replication is not 100% accurate
Errors occur when copying DNA
DNA damaged
Ultraviolet light
X-rays
Cigarette smoke
Nitrates (smoked meat)
Pesticides & Herbicides

21. Mutations It is any change in the DNA of a gene or chromosome
Cell produces incorrect protein during synthesis.
Resulting in different traits from what is considered normal.
Types of mutations:
Deletion: one base pair is removed
Addition: base pair added
Substitution: a base pair is switched for another.

23. The End