12-1 structure and Rosland 2016

Views:
 
Category: Education
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

Slide1:

DNA : History and Structure

Slide2:

Shape is called double helix.

Slide10:

10 Our genes are on our chromosomes. Chromosomes are made up of a chemical called DNA.

Slide11:

What EXACTLY is DNA?

Slide12:

DNA _______ _________ __________ in cells Stores genetic information

DNA:

DNA is the blueprint of life . DNA contains the instructions for making proteins in a cell . DNA is made of smaller units called Nucleotides

contain: _______, _________, _______, _______ and ________ :

contain: _______, _________, _______, _______ and ________ NUCLEOTIDE are built from ___________ subunits CARBON HYDROGEN OXYGEN PHOSPHORUS NITROGEN DNA is a NUCLEIC ACID

ONE SPECIAL KIND of NUCLEOTIDE is used by cells to _______________________:

ONE SPECIAL KIND of NUCLEOTIDE is used by cells to _______________________ ATP Sugar =_____________ Nitrogen base =__________ +___ PHOSPHATE groups Image by: Riedell RIBOSE ADENINE 3 Store and transport ENERGY RIBOSE

Slide16:

RNA _______________________ __________ out ________ Helps with _________________ Image from: Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved CARRIES INFORMATION from DNA to cell PROTEIN SYNTHESIS

Slide17:

The DNA in cells can hold lots of information and are very long. Each cell has about 6 feet of DNA.

The Double Helix Molecule:

18 The Double Helix Molecule The DNA double helix has two strands twisted together.

One Strand of DNA:

19 One Strand of DNA One strand of DNA is a polymer of nucleotides. One strand of DNA has many millions of nucleotides. nucleotide

One Strand of DNA:

20 One Strand of DNA The backbone of the molecule is alternating phosphates and deoxyribose sugar The teeth are nitrogenous bases . phosphate deoxyribose bases

Four nitrogenous bases:

21 Four nitrogenous bases Guanine G Adenine A Cytosine C Thymine T DNA has four different bases:

Two Kinds of Bases in DNA:

22 Two Kinds of Bases in DNA Pyrimidines are single ring bases . Purines are double ring bases. C C C C N N O N C C C C N N N N N C

Thymine and Cytosine are pyrimidines:

23 Thymine and Cytosine are pyrimidines Thymine and cytosine each have one ring of carbon and nitrogen atoms. C C C C N N O N cytosine C C C C N N O O thymine C

Adenine and Guanine are purines:

24 Adenine and Guanine are purines Adenine and guanine each have two rings of carbon and nitrogen atoms. C C C C N N N Adenine N N C C C C C N N O N Guanine N N C

Two Stranded DNA:

25 Two Stranded DNA Remember, DNA has two strands that fit together something like a zipper. The teeth are the nitrogenous bases but why do they stick together?

Hydrogen Bonds:

26 C C C C N N O N C C C C N N O N N N C Hydrogen Bonds The bases attract each other because of hydrogen bonds. Hydrogen bonds are weak but there are millions and millions of them in a single molecule of DNA. The bonds between cytosine and guanine are shown here with dotted lines

Hydrogen Bonds, cont.:

27 Hydrogen Bonds, cont. When making hydrogen bonds, cytosine always pairs up with guanine Adenine always pairs up with thymine Adenine is bonded to thymine here C C C C N N N N N C C C C C N N O O C

Write this down! Chargraff’s Rule::

Write this down! Chargraff’s Rule: Adenine and Thymine always join together A T Cytosine and Guanine always join together C G

Slide29:

This is NUCLEOTIDE

2 KINDS of NUCLEIC ACIDS:

2 KINDS of NUCLEIC ACIDS DNA= __________________ Deoxyribonucleic acid Image from: http://www.tokyo-med.ac.jp/genet/picts/dna.jpg ______________ STRANDED SUBUNITS: A, T, G, C (No U) DOUBLE

2 KINDS of NUCLEIC ACIDS:

2 KINDS of NUCLEIC ACIDS RNA= ________________ Ribonucleic acid _________STRANDED Subunits: A, U, G, C (NO T) Image from: http://www.makingthemodernworld.org.uk/learning_modules/biology/01.TU.03/illustrations/01.IL.09.gif SINGLE

Slide32:

Image by: Riedell NUCLEOTIDES 2 SUGARS can be used: ____________ (_____) ________ (____) DEOXYRIBOSE DNA RIBOSE RNA Sugars: http://fig.cox.miami.edu/~cmallery/150/chemistry/fig5x27b.jpg Arrow: http://www.gifanimations.com/action/ImageDisplay/1/2/11/next

5 NITROGEN BASES:

5 NITROGEN BASES _____________ = A _____________ = G _____________ = C _____________ = T (only in DNA) _____________ = U (only in RNA) ADENINE GUANINE CYTOSINE THYMINE URACIL

Slide34:

These Nitrogen bases: _____________ NO __________ Image by: Riedell MAKING _____ USES: uracil DEOXYRIBOSE DNA A, T, C, or G SUGAR = _______________ Sugars: http://fig.cox.miami.edu/~cmallery/150/chemistry/fig5x27b.jpg

Slide35:

SUGAR = __________ These Nitrogen bases _____________ NO __________ Image by: Riedell Making _____ uses” thymine RIBOSE RNA A, U, C, or G Sugars: http://fig.cox.miami.edu/~cmallery/150/chemistry/fig5x27b.jpg

DNA molecule forms a HELIX or “twisted ladder”:

DNA molecule forms a HELIX or “twisted ladder” __________ bonds _________ with _________ bonds __________ with Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif ADENINE THYMINE CYTOSINE GUANINE

Slide37:

The structure, base-pairing, and model of DNA was discovered by several people. Rosalind Franklin used a technique called X-ray diffraction and showed that DNA consisted of two strands wrapped around each other with the nitrogenous bases in the middle and the distance between the two strands being consistent. Erwin Chargaff discovered that regardless of the sample of DNA, the percentages of C ’ s and G ’ s are almost equal and the same thing is true between A ’ s and T ’ s.

Slide38:

Write the complementary bases for the following strand: CGATACAGTTAA

Slide39:

Watson and Crick (1953) Discovered structure of DNA. One of the most important biological discoveries in the last 100 years .

Slide40:

Rosalind Franklin? Who is she?

Slide41:

She took X-Ray pictures of DNA’s structure and lectured about phosphate being a part of the outside of the molecule. - actual picture of DNA

Slide42:

She took X-Ray pictures of DNA’s structure and lectured about phosphate being a part of the outside of the molecule. Watson attended her lectures.

Slide43:

Maurice Wilkins who was working with Rosalind Franklin showed Watson her experiments.

Slide44:

Watson and Crick used her photographs, and information from lectures and experiements to create a model of the helix.

Slide45:

In 1962,

Slide46:

In 1962, Watson,

Slide47:

In 1962, Watson, Crick,

Slide48:

In 1962, Watson, Crick, and Wilkins

Slide49:

In 1962, Watson, Crick, and Wilkins won the Nobel Prize for physiology/medicine.

Slide50:

In 1962, Watson, Crick, and Wilkins won the Nobel Prize for physiology/medicine. Franklin had died of Ovarian Cancer.

Slide51:

The cancer that killed her may have been caused by working with X-Rays.

Slide52:

The Nobel Prize only goes to living recipients, and can only be shared among three winners.

Slide54:

Who thinks we should give an honorary Nobel Prize to Rosalind Franklin?

Slide55:

Who thinks we should give an honorary Nobel Prize to Rosalind Franklin? “The Lady of DNA”

Slide56:

Activity! Draw DNA in Detail.

Slide61:

A A A G T C T T Copyright © 2010 Ryan P. Murphy

Slide62:

Each unit called a nucleotide of DNA consists of 3 parts. - - - Copyright © 2010 Ryan P. Murphy Phosphate backbone A 5-carbon sugar (deoxyribose) A nitrogen base attached to the sugar

Slide63:

A A A G T C T T Nucleotide

Slide64:

A A A G T C T T Phosphate Backbone

Slide65:

A A A G T C T T Ribose Sugar Copyright © 2010 Ryan P. Murphy

Slide66:

A A A G T C T T Nitrogen Base Copyright © 2010 Ryan P. Murphy

Slide67:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine Copyright © 2010 Ryan P. Murphy

Slide68:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine Copyright © 2010 Ryan P. Murphy

Slide69:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine Copyright © 2010 Ryan P. Murphy

Slide70:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine Copyright © 2010 Ryan P. Murphy

Slide71:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine Copyright © 2010 Ryan P. Murphy

Slide72:

There are four different types of nucleotides found in DNA A is for adenine G is for guanine C is for cytosine T is for thymine

Slide73:

A goes with T C goes with G WRONG! T – C or G - A

Slide74:

Activity! Which of the base pairs below is incorrect. Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Adenine Adenine – Thymine Adenine – Thymine Guanine – Cytosine

Slide75:

Answers! Which of the base pairs below is incorrect. Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Adenine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Same challenge next slide 

Slide76:

Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Adenine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine

Slide77:

Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Adenine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine

Slide78:

The almost final challenge on next slide, find the incorrect base pairing.

Slide79:

Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Thymine - Cytosine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine – Adenine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine – Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Guanine – Cytosine

Slide80:

Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Thymine - Cytosine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine – Adenine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine – Adenine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Guanine – Cytosine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Adenine – Thymine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Adenine -- Thymine Cytosine – Guanine Adenine – Thymine Guanine – Cytosine Adenine –- Thymine Guanine –- Cytosine Thymine - Adenine Thymine - Adenine Cytosine - Guanine Adenine –- Thymine Guanine –- Cytosine Guanine – Cytosine

Slide81:

Try and figure out the picture under the boxes. Raise your hand when you think you know. You only get one guess.

Slide89:

“Remember me.” “I’m Rosalind Franklin and I took X-ray pictures of DNA.”

Slide90:

Activity! What is the mystery animal in the box below? G - ___ T - ___ A - ___ Copyright © 2010 Ryan P. Murphy

Slide91:

Answer! What is the mystery animal in the box below? G - __ T - __ A - __ CATGAA! C A T

Slide92:

Activity! What is best game to play in the whole wide world? A - ___ T - ___ C - ___

Slide93:

Answer! What is best game to play in the whole wide world? A - _ T __ T - _ A __ C - _ G __

Slide94:

What are differences between DNA and RNA? Copyright © 2010 Ryan P. Murphy

Slide95:

RNA - Single strand - Uracil replaces Thymine Copyright © 2010 Ryan P. Murphy

Slide96:

RNA - Single strand. - Uracil replaces Thymine Copyright © 2010 Ryan P. Murphy

Slide97:

RNA - Single strand. - Uracil replaces Thymine. Copyright © 2010 Ryan P. Murphy Just Ribose sugar, not deoxy like DNA

Slide98:

RNA - Single strand. - Uracil replaces Thymine. Copyright © 2010 Ryan P. Murphy

authorStream Live Help