DNA Structure and Replication DNA Rap Song .
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Transcript of DNA Structure and Replication DNA Rap Song .
DNAStructure and Replication
DNA Rap Song
http://www.youtube.com/watch?v=d1UPf7lXeO8
Student Expectations
B 6.A1
Identify components of DNA.
DNA Structure
DNA stands for Deoxyribonucleic Acid
Shape: Double helix
Monomers: Nucleotides (has 3 parts) Sugar, (deoxyribose), phosphate nitrogenous base
Bases are held together by hydrogen bonds.
Four Nitrogenous Bases Adenine (A) Guanine (G) Cytosine (C) Thymine (T)
Purines (double ring) Adenine and Guanine
Pyrimidines (single ring) – Cytosine and Thymine
Chargaff’s rule: Adenine pairs with thymine. A –T T – A Guanine pairs with cytosine. G – C C – G
Nucleotides: Purines Pyrimidines
Adenine Guanine
Cytosine Thymine
Phosphate group
Sugar:
Deoxyribose
Thymine Cytosine
Build a DNA molecule
http://learn.genetics.utah.edu/content/begin/dna/builddna/
A Closer Look at DNA: Page 294
Hydrogen bonds
Nucleotide
Sugar-phosphate backbone
Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
A closer look at DNA:How DNA condenses
Chromosome
Supercoils
ChromatinHistones
DNA
double
helix
Centromere
Student Expectation
B 5.A1
Describe the stages of the cell cycle, including
deoxyribonucleic acid (DNA) replication.
What is Replication?
The process of copying DNA during S phase of interphase in the nucleus
Makes sure that a daughter cell will have a complete set of chromosomes
Original strand of DNA serves as a template for 2 new strands Template: a pattern; an original model
Each new strand will be identical to the original strand because of Chargaff’s rule.
How does replication work?
1) Helicase unwinds the double helix, forming a “replication fork,” where replication takes place
2) DNA polymerase bonds the necessary nucleotides to the original DNA strand to complete 2 new DNA molecules
3) DNA polymerase also “proofreads” the new DNA strand to make sure it is an exact copy of the original DNA
DNA Replication Facts:
DNA polymerase can only work in one direction so: 2 new strands of DNA are made in opposite
directions One strand is made in sequence of nucleotides The other strand is what we call the “lagging
strand” because nucleotides are added in fragments
DNA Replication: Page 298
Growth
Growth
Replication fork
DNA polymerase
New strand
Original strand DNA
polymerase
Nitrogenous
bases
Replication
fork
Original strand
New strand
Videos
http://www.youtube.com/watch?NR=1&feature=fvwp&v=bW5JnYZImJA
http://www.youtube.com/watch?v=5VefaI0LrgE&feature=related