8.2 Structure of DNA Set up Cornell Notes on pg. 67 Topic: 8.2 Structure of DNA Essential Question:...
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8.2 Structure of DNA •Set up Cornell Notes on pg. 67 •Topic: 8.2 Structure of DNA •Essential Question: Explain the base- pairing rules. How many types of nucleotides are there? How do they differ? •Don’t forget to 2.1 Atoms, Ions, and Molecules Explain the base-pairing rules. How many types of nucleotides are there? How do they differ? 8.2 Structure of DNA Key Concept:DNA structure is the same in all organisms
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Transcript of 8.2 Structure of DNA Set up Cornell Notes on pg. 67 Topic: 8.2 Structure of DNA Essential Question:...
8.2 Structure of DNA
•Set up Cornell Notes on pg. 67
•Topic: 8.2 Structure of DNA
•Essential Question:
Explain the base-pairing rules. How many types of nucleotides are there? How do they differ?
•Don’t forget to add it to your T.O.Contents!
2.1 Atoms, Ions, and Molecules
Explain the base-pairing rules. How many types of nucleotides are there? How do they differ?
8.2 Structure of DNA
Key Concept:DNA structure is the same in all organisms
8.2 Structure of DNA
KEY CONCEPT DNA structure is the same in all organisms.
8.2 Structure of DNA
DNA is composed of four types of nucleotides.• Each nucleotide has three parts.
1. a phosphate group
2. a deoxyribose sugar
3. a nitrogen-containing basephosphate group
deoxyribose (sugar)
nitrogen-containingbase
1
2
3
Covalent bonds
base
backbone
8.2 Structure of DNA
• The nitrogen containing bases are the only difference in the four nucleotides.
•Thymine- T
•Adenine- A
•Guanine- G
•Cytosine-C
BASES
8.2 Structure of DNA
8.2 Structure of DNA
Watson and Crick determined the three-dimensional structure of DNA by building models.
• They realized that DNA is a double helix– backbone on the outside– bases on the inside.
backbone
bases
8.2 Structure of DNA
• Watson and Crick’s discovery built on the work of Rosalind Franklin and Erwin Chargaff.
– Franklin’s x-ray images suggested that DNA was a double helix of even width.
– Chargaff’s rules stated that A=T and C=G.
8.2 Structure of DNA
TAC
G
Nucleotides always pair in the same way.
• the helix has a uniform width.– Ex: ladder
– A pairs with T
– C pairs with G
8.2 Structure of DNA
• The backbone is connected by covalent bonds.
hydrogen bond covalent bond
• The bases are connected by hydrogen bonds.
backbone
Hydrogen bond
Bases (A,T,G,C)
8.2 Structure of DNA
A
T
CC G
ATG
A
T
G C
8.2 Structure of DNA
GATTACAATCGATCGATCTAATGTTAGCTAGCTA
TAGGACTACTAGTCGTA
ATCCTGATGATCAGCAT
Using the base pairing rules- complete the DNA strand:
8.2 Structure of DNA
Adenine (A) = GreenThymine (T) = PinkCytosine (C) = YellowGuanine (G) = Orange
Have Your DNA & Eat It Too
* I need to check your work before you eat the DNA!!!!!
