dna structure. objectives describe 3 parts of a nucleotide describe a dna molecule demonstrate...
TRANSCRIPT
DNA Structure
OBJECTIVES
• Describe 3 parts of a NUCLEOTIDE
• Describe a DNA molecule
• Demonstrate COMPLIMENTARY base pairing
DNA is Genetic Material
• DNA stands for: DEOXYRIBONUCLEIC ACID
– Controls protein production in cells
– Made up of many genes which control traits
Why DNA is Important
• Passes genetic information from generation to generation
• Traits are controlled by DNA
• DNA replicates with little error
• Can’t live with out DNA because it part of everything in the body
DNA structure
• DNA is a double Helix • Meaning DNA has two
strands. It looks like a twisted ladder
• DNA is polymer made up of units called NUCLEOTIDES
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DNA StructurePO4
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A molecule of DNA is formed by millions monomers called nucleotides joined together in a long chain
Nucleotide Structure3 important parts:
1. Phosphate group
2. Sugar (Deoxyribose)
3. Nitrogenous base (G,C,A,T)
Phosphate &
sugar m
ake up
the “back
bone”.
4 Nitrogenous Bases
ADENINE (A)
THYMINE (T)
CYTOSINE (C)
GUANINE (G)
2 PURINES
The PURINES form hydrogen bonds with the PYRIMIDINES
PYRIMIDINES
Base Pairing
ADENINE always pairs with THYMINE
CYTOSINE always pairs with GUANINE
Notice the number of hydrogen bonds formed
DNA structure
Each strand is COMPLEMENTARY to the other
Complementary Strands
• If we know the DNA sequence of one strand, we can predict the DNA sequence of it’s complement
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C C GG A AT T
PO4
C
PO4
CPO4
A
PO4
A
PO4
T
PO4
T
PO4
G
PO4
G
DNA Structure• DNA strands are
ANTI-PARALLEL– Phosphates run in
different directions
What to do next
• Complete worksheet in class
• When done call me over so I can stamp your sheet
• Homework: BRING YOUR BOOK TO CLASS!!
Replication
• http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html#