Download 2_Notes_DNA Structure and Replication

Packet 8: DNA
Name: _____________________________
Hour: _______
Notes: DNA Structure and Replication
What is DNA?
• DNA:
– 1. molecule that has the ________________ for all cell activity
– 2. molecule that is ___________ from generation to generation
– 3. located in the ________________
Structure of DNA
• Made of __________________ (monomer)
Nucleotide consists of:
___________________ sugar (sugar)
Phosphate group (_____________________)
Nitrogen containing base (_____________________)
–
Review Questions
• 1. What makes up DNA? ________________________________________
• 2. Where is DNA located? ________________________________________
• 3. What three parts make up a nucleotide? _______________________
• 4. What type of sugar is in DNA? ___________________________________
Sugar-Phosphate Backbone
• ____________-________________ Backbone of DNA:
– Formed by the ____________ and ____________
of each nucleotide bonded together
– Sides of the ladder
Nitrogeneous (Nitrogen) Bases
• Nitrogen Bases: Rungs or Steps of Ladder
– ______________________
– ______________________
– ______________________
– ______________________
• __________________ ALWAYS pairs with ____________________
• __________________ ALWAYS pairs with ____________________
Double Helix: The “_______________ _________________”
• Discovered by Watson and Crick
• Double: _______ __________ ____ _____ connected by nitrogen bases
(hydrogen bonds)
• Helix: Nucleotides _________ together
• Always an ___________ ______________ of A and T
• Always an equal number of ____ and ____
Review Questions
 1. What two parts of a nucleotide make up the “backbone”?
 2. How many different bases exist in DNA? What are they?
 3. What bases bond together in DNA?
 4. Why is DNA called a “double helix”?
How Does Replication Occur?
• The _________ ____________ of DNA must be “_______________”
– “Unzipping” occurs when the _______________ ________ between
the nitrogen bases are _____________
• DNA ________________: enzyme (protein) that _____________ hydrogen
bonds and _________________ DNA
• DNA ____________________: enzyme (protein) that ___________ ______
_____________________ and attaches them to old strand
• Each strand is duplicated _____________________
– __________ bases are brought in to complement the old
(______________) strand
– New strand of ________ consists of an ______, parent __________
and a ____________, daughter ____________________
Review
 1. What two parts of a nucleotide make up the “backbone”?
 2. How many different bases exist in DNA? What are they?
 3. What bases bond together in DNA?
 4. Why is DNA called a “double helix”?