Warm Up What are enzymes made of? What is the process of putting two glucose molecules together? Breaking them apart? What does Chargaff’s Rule say?. Monday 11/5/12. DNA Structure QQ (TOC#. QQ#1: What do you know about the structure of DNA? Be as detailed as Possible .
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Warm Up What are enzymes made of? What is the process of putting two glucose molecules together? Breaking them apart? What does Chargaff’s Rule say? Monday 11/5/12
DNA Structure QQ (TOC# • QQ#1: • What do you know about the structure of DNA? • Be as detailed as Possible
Deoxyribose Nucleic Acid: Structure Notes Called a double helix (a spiral ladder)
DNA is a Polymer • DNA’s Monomers: • repeating subunits called NUCLEOTIDES • Nucleotidesconsist of three parts: • Phosphate Group • Sugar Group • Nitrogenous Base QQ#2 What are the three parts of the nucleotide?
Nucleotide Structure Copy the Diagram In your notes: • The phosphate bonds to what is called the 5’ (five prime) carbon of the sugar molecule. • The base bonds with the sugar at the 1’ carbon. • Can be one of four bases: • Adenine, Thymine, Cytosine, Guanine Discuss: How do you think these may link together to form a polymer?
QQ#3 • Draw a visual to represent two nucleotides bonding together
DNA’s Repeating Structure • DNA is directional • The nucleotides are connected together by a phosphodiester bond between phosphate groups at the 3’ and 5’ carbon on the the sugar molecule. • These bonds create one side of the strand of DNA. • The other (complementary) strand runs in the opposite direction connected in the middle by the bases • called anti-parallel chain
Bases • In general • bases can accept hydrogen ions or more generally, donate a pair of valence electronswhen bonding • The opposite of an acid • Categories of Bases • pyrimidines – one ring • Cytosine and Thymine • purines – two rings • Adenine and Guanine
QQ#4: • Can you think of a way to remember which bases are purines and which are pyrimidines? • Categories of Bases • pyrimidines – one ring • Cytosine and Thymine • purines – two rings • Adenine and Guanine
Hydrogen Bonds • A Purine always bonds with a Pyrimidine • Bases are connected across middle of helix: • Adenine forms (2) h-bonds with Thymine • Guanine forms (3) h-bonds with Cytosine • These bonds hold the two strands of DNA together and cause the twisting to occur
The entire code that instructs our cells depends on the order of Adenine, Guanine, Thymine, Cytosine • The specific bonding angles of the nucleotides forces the helix shape. • Within the helix there is a major and minor groove
Major and Minor Grooves • Caused by bonding angles • Major groove allows proteins to bond: important for replication. • Each full twist of the helix has 10 nucleotides
Putting it All together http://www.youtube.com/watch?v=ZGHkHMoyC5I
Exit Slip • On a separate scratch piece of paper, answer the following questions. 1. What do you know now about DNA structure? 2. Compare this knowledge with what you knew before? 3. Why is the structure of DNA important to the essential questions: In what way(s) does your DNA define you? 4. Predict how the structure of DNA relates to how all organisms have the same exact DNA in all cells
Your Model • You may create a model with our without the major and minor grooves. All other components of DNA structure must be included for accuracy