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DNA Model Cut and Color the DNA pieces.

Do not cut the triangle out of C, you need it for

gluing

When you are done with your nucleotides

connect to your partner.

Work on the Discovering DNA worksheet.

Before the end of the period connect your set

to at least 4 other partners.

Cover Page due TOMORROW1

Warm up 11/15

What are the 4 DNA nucleotide nitrogen bases?

What are the pairing rules for the bases?

What parts do all nucleotides have in common?

What is a purine? A pyrimidine?

Checking:

Cover Page &

Discovering DNA/Vocab2

Chapter 10 NotesStructure of DNA

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Structure of DNADNA is Made up repeating units of nucleotides

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Structure of DNADNA is Made up repeating units of nucleotides

Three parts of a Nucleotide are:

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Structure of DNADNA is Made up repeating units of nucleotides

Three parts of a Nucleotide are:

1. . . . Deoxyribose sugar Deoxyribose sugar Deoxyribose sugar Deoxyribose sugar 2. Phosphate group2. Phosphate group2. Phosphate group2. Phosphate group

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Structure of DNADNA is Made up repeating units of nucleotides

Three parts of a Nucleotide are:

1. . . . Deoxyribose sugar Deoxyribose sugar Deoxyribose sugar Deoxyribose sugar 2. Phosphate group2. Phosphate group2. Phosphate group2. Phosphate group3. Nitrogen3. Nitrogen3. Nitrogen3. Nitrogen----containing containing containing containing

basebasebasebase 7

Nitrogen Containing Bases

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Base Pairing Rules

Adenine pairs with Thymine

(2 hydrogen bonds)

Guanine pairs with Cytosine

(3 hydrogen bonds)

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Base Pairing Rules

Chargaff’s Rule: The amount of adenine always

equals the amount of thymine, and the amount of

guanine equals cytosine.

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Assignment

Homework: PQRST pg. 200-203 (due Monday)

Due in Notebook

Class work: DNA Book–cover page and page 1 (Due tomorrow)

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DNA Shape and Structure

Described as a Double

Helix: Double

stranded, coiled like a

spiral stair

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The Double Helix

Described as a Double

Helix: Double

stranded, coiled like a

spiral stair

The backbone of the

strands are alternating

phosphate and

deoxyribose sugars 13

Histones

DNA is tightly coiled around proteins

called histones to make the long DNA

molecule easier to manage.

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What are the three parts of a

nucleotide?

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What Base Bonds to Adenine?

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What Base Bonds to Guanine?

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http://www.youtube.com/watch?v=VegLVn_1oCE

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Purpose of DNA ReplicationWhy would DNA replicate?

When would DNA replication occur?

To make a copy of it’s DNA for the To make a copy of it’s DNA for the To make a copy of it’s DNA for the To make a copy of it’s DNA for the cell to divide.cell to divide.cell to divide.cell to divide.

Mitosis

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Steps of DNA Replication

1. Helicase unzips and

unwinds the DNA

strands by breaking

the hydrogen bonds

a. Sugar-Phosphate=

Covalent Bonds

b. Nitrogen Bases =

Hydrogen bonds 22

Steps of DNA Replication

2. Enzymes called DNA

Polymerase add

complementary

nucleotides.

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Steps of DNA Replication

3. Process continues until entire strand is copied

Result is two strands of DNA

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AAT CC A AA G

A T T T T TGG C

1. First the DNA must unzip:Enzymes split apart the base pairs and unwind the DNA.

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AAT CC A AA G

A T T T T TGG C

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AAT CC A AA G

A T T T T TGG C

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AAT CC A AA G

A T T T T TGG C

TT

2. Bases pair up: Free nucleotides in the cell find their complementary bases along the original strand.

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AAT CC A AA G

A T T T T TGG C

T

A C

T

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AAT CC A AA G

A T T T T TGG C

T A

C T

AT

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AAT CC A AA G

A T T T T TGG C

T A

C T

A

T

C

G

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AAT CC A AA G

A T T T T TGG C

T A

C T

A

T

C

G

A C A

TGT

T

G

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AAT CC A AA G

A

A T T T T TGG C

T A

C T

A

T

C

G

A C A

TGTT

G

A

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AAT CC A AA G

A

A T T T T TGG C

T A

C T

A

T

C

G

A C A

TGTT

G

A

The DNA is now duplicated:

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End Result

Two identical molecules of DNA

They have one new and one old

strand

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Mechanism of DNA

ReplicationDNA is said to be

semiconservative since

each new DNA

molecule made has one

parent strand and one

daughter strand.

Can also be said: one old strand and one new strand 36

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Accuracy and Repair

Copies must be 100% accurate

Mutation= change in nucleotide at one location

Enzymes proofread and fix errors

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Assignment

Homework: PQRST pg. 200-203 (due Monday)

Due in Notebook

Class work: DNA Book–cover page and pages 1-2 (Due Tuesday)

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