1. Genetics

2. What is DNA?
DNA is a nucleic acid (a macromolecule) made up of monomers called nucleotides
Deoxyribonucleic Acid can be found in the nucleus of eukaryotic cells but is free- floating in a prokaryote’s cells
DNA’s job is to store all of an organism’s genetic information

3. History of DNA
Rosalind Franklin and Wilkins used new X-ray diffraction pictures of DNA in order to determine the structure of DNA
Watson and Crick are credited with finally piecing together all the information previously gathered on DNA’s shape and structure.
They determined DNA’s structure is a double helix
Another scientist named Chargaff analyzed the amounts of different nucleotides found in DNA and noticed a pattern.
The amount of A-T was always the same and the amount of C- G was always the same
Video

4. DNA Structure Each nucleotide monomer in DNA is made up of 3 parts
A phosphate
A sugar (deoxyribose)
Nitrogenous base (adenine, thymine, cytosine, guanine)
DNA’s double helix structure is made up of 2 strands of nucleotides twisted around each other like a spiral ladder
The sides of the ladder are made of phosphates and sugar
The rungs of the ladder are made of nitrogenous bases

5. Nitrogenous Bases Adenine and Guanine are called purines
Thymine, Cytosine and Uracil (found on RNA) are pyrimidines

6. DNA Structure Hydrogen Bonds are found between the bases
Adenosine (A) always pairs with Thymine (T) and Guanine (G) always pairs with Cytosine (C)
This is called Complementary base pairing
Each side of DNA has an opposite orientation. One side ends in a free sugar (3’) and the other side ends in a phosphate (5’)
This makes the two strands of DNA antiparallel
How the code works? The nucleotide sequence forms your genetic code. Each individual has a different sequence, but about 99.9% of your DNA is identical to one another

7. What would the complementary base pairs be for this strand of DNA?

8. DNA Semiconservative Replication
Cells prepare for division by replicating DNA
Doubles the amount of DNA in the cell by making an exact copy of the existing DNA
DNA is in the form of chromatin (loose coils) in the nucleus
Enzymes like DNA polymerase and Helicase are needed for replication
Free nucleotides are also found in the nucleus

9. DNA Semiconservative Replication
Because DNA is double stranded, one strand can act as a template during replication
DNA Replication happens in 3 basic steps
Enzymes start to separate or unzip the 2 strands of DNA
The enzyme Helicase unzips a portion of DNA called the origin of replication
Free nucleotides pair up with a complementary base pair on the original strand of DNA with the help of DNA Polymerase
The other unzipped strand also acts as a template for the formation of another new strand of DNA
This process is called semi-conservative replication because ½ of a pre-existing DNA molecule is saved
No DNA molecule is ever completely new

12. Accuracy of Replication
Replication can occur up to 4000 nucleotides per second
Complex organisms replicate DNA with multiple origins of replication, simple organisms like bacteria need only one
Repair enzymes detect and correct errors (mutations) that can occur during replication
DNA Replication Simulation

13. RNA- Ribonucleic Acid RNA is composed of monomers called nucleotides
Each Nucleotide consists of:
A phosphate
A sugar (ribose)
Nitrogenous base (Adenine, URACIL, guanine, cytosine)
RNA is a single stranded Nucleic Acid used for protein synthesis
There are 3 types of RNA: Messenger RNA (mRNA), Transfer RNA (tRNA), Ribosomal RNA (rRNA)

14. http://www.popsci.com/science/article/2013-03/watch- absolutely-beautiful-animated-explainer-dna