SlideShare a Scribd company logo
MOLECULAR BIOLOGY
GENE ORGANIZATION
TODAY WE GO THOUGH THE TOPICS
 Structural aspects of DNA
 The double helix model
 Conformations of DNA
QUESTIONS WE COVER
 What is DNA ?
 Structure of DNA ?
 History of DNA?
 Types of DNA?
 Double helix model of DNA?
 Who discovered the DNA?
 With what DNA is made up of?
STRUCTURAL ASPECTS OF DNA
DNA
 Deoxyribonucleic acid, or DNA, is a molecule that
contains the instructions an organism needs to develop,
live and reproduce.
 These instructions are found inside every cell, and are
passed down from parents to their children.
 Its one long molecule that contains our genetic ‘code’.
DEFINITION OF DNA
 Deoxyribonucleic acid is a molecule composed of two
polynucleotide chains that coil around each other to form
a double helix carrying genetic instructions for the
development, functioning, growth and reproduction of all
known organisms many viruses.
 It is a carrier of all genetic information.
 DNA and RNA are nucleic acids.
HISTORY OF DNA
 Many people believe that American biologist James Watson and
English physicist Francis Crick discovered DNA in the 1950’s. In
reality, this is not the case. Rather, DNA was first identified in the late
1860’s by Swiss chemist Friedrich Miescher.
 The discovery in 1953 of the double helix, the twisted- ladder structure
of deoxyribonucleic acid(DNA), by James Watson and Francis Crick
marked a milestone in the history of science and gave rise to modern
molecular biology, which is largely concerned with understanding how
genes control the chemical processes.
STRUCTURE OF DNA
 DNA is made up of molecules known as nucleotides.
 Each nucleotide contains a sugar and phosphate group as well as nitrogen
bases.
 These nitrogen bases are further broken down into four types, including
• Adenine (A)
• Cytosine (C)
• Guanine (G)
• Thymine (T)
 DNA’s structure is a double stranded helix, and it resembles
the look of a twisted ladder.
 The sugar and phosphates are nucleotide strands that form the
long sides.
 The nitrogen bases are rungs.
 Every rung is actually two types of nitrogen bases that pair
together to form a complete rung and hold the long strands of
nucleotides together.
 Remember, there are four types of nitrogen bases, and they
pair together specifically-adrenaline pairs with thymine, and
guanine with cytosine.
 T=A AND G=C
DNA
BACKBONE
PHOSPHATE SUGAR
BASE
NITROGEN
BASE
• Human DNA is unique in that it is made up of nearly 3
billion base pairs, and about 99 percent of them are the
same in every human.
• However, it’s the sequence of these bases that determines
what information is available to both build and maintain
any organism.
DOUBLE HELIX STRUCTURE
 Double helix is the description of the structure of a DNA molecule.
 A DNA molecule consists of two strands that wind each other like a
twisted ladder.
 Each strand has a backbone made of alternating groups of sugar(de-
oxy-ribose) and phosphate groups.
 Attached to each sugar is one of four bases: adenine(A), cytosine(C),
guanine(G), or thymine(T).
 The two strands are held together by bonds between the bases, adenine
forming a base pair with thymine, and cytosine forming a base pair with
guanine.
ILLUSTRATION
CONFORMATIONS OF DNA
 The different types of DNA are:
• B-DNA
• A-DNA
• Z-DNA
• C-DNA
• D-DNA
• E-DNA
B-DNA
 B-form DNA is a right handed double helix, which
was discovered by Watson and crick based on the x-
ray patterns.
 It is the common form of DNA exists under normal
physiological condition.
 The double strands of B-DNA run in opposite
directions.
 Most common, originally deduced from X-ray
diffraction of sodium salt of DNA fibers at 92%
relative humidity.
 DNA molecule consists of 2 helical polynucleotide
chains coiled around common axis.
 The 2 chains run in opposite direction, they are
antiparallel, the plane of bases are perpendicular to
helix axis. Complementary base pairing.
 The grooves provide surface with which proteins,
chemicals, drugs can interact.
 The proteins access genetic information easily
through the major groove of B-DNA.( So it is more
stable).
A-DNA
 A-form DNA is a right handed double helix,
which was discovered by Rosalind franklin,
who was named the A and B forms.
 A-DNA originally identified by X-ray
diffraction of analysis of DNA fibers at 75%
relative humidity.
 Occur only in dehydrated sample of DNA,
such those used in crystallographic
experiments.
 It is one of possible double helical structure
which DNA can adopt along with other two
biological active helix structure.(B-DNA,Z-
DNA)
 Short and fat compared B-DNA.
 The bases are not tilted and are grooves are
also not as deep as B-DNA.
Z-DNA
 It is a left handed double helix structure
winds to left in zig-zag manner.so they
termed as Z-DNA.
 It is discovered by Rich, Nordheim &Wang
in 1984
 It has antiparallel strands as DNA and it is
long and thin compared to B-DNA
 Adjacent sugar have alternating orientation.
And has one deep helical groove
 Z-DNA has both purines and Pyramidines.
 purines has Syn conformation (bases &
sugar are near and on same side).
 Pyramidines has anti conformation ( bases
& sugar are distant and on opposite sides).
C-DNA, D-DNA, AND
E-DNA ARE THE
FORMS OF DNA.
A-DNA, B-DNA AND Z-
DNA ARE THE TYPES OF
DNA.
C-DNA
 It is often used to clone eukaryotic genes
in prokaryotes.
 C-DNA has it’s own significance in PCR
technique.
 C-DNA strands for complementary DNA.
 It is synthesized from a single-stranded
RNA.
 It is formed at 66% relative humidity and
in presence of Li+ and Mg2+.
 It is a right handed DNA.
 It has smaller diameter than that of A-
DNA and B-DNA.
D-DNA
 It is a rare variant with 8 base pairs per
helical turn.
 These forms of DNA found in some
DNA molecules devoid of guanine.
 The tilt of 16.7° from the axis of the
helix.
 The axis rise of 3.03A° per base pairs.
 Actually 2 different forms of D-DNA.
• D(A): takes part in D-A-B
transition.
• D(B): associated with D-B change
of conformation.
E-dna
 Extended or eccentric DNA.
 E-DNA has a long helical axis rise
and base perpendicular to the
helical axis.
 E-DNA allowed to crystallize for a
period time longer, the methylated
sequence forms standard A-DNA.
 E-DNA is the intermediate in the
crystallographic pathway from B-
DNA to A-DNA.
DNA structure, history , definition and double helix model
DNA structure, history , definition and double helix model

More Related Content

What's hot

Nucleic acid database
Nucleic acid database Nucleic acid database
Nucleic acid database bhargvi sharma
 
Dna replication
Dna replicationDna replication
Dna replication
Avishek Majumder
 
DNA Replication
DNA ReplicationDNA Replication
DNA Replication
PRABAL SINGH
 
Structure of DNA
Structure of DNAStructure of DNA
Structure of DNA
Jenson Samraj
 
DNA double helix
DNA double helixDNA double helix
DNA double helix
Abdul Rehman
 
Chemistry of DNA
Chemistry of DNAChemistry of DNA
Chemistry of DNA
Ashok Katta
 
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic material
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic materialNucleic acid and its chemistry - DNA, RNA, DNA as genetic material
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic material
Dhanuja Kumar
 
DNA & RNA
DNA & RNADNA & RNA
DNA & RNA
Eneutron
 
DNA POLYMERASE
DNA POLYMERASE DNA POLYMERASE
DNA POLYMERASE
Rabia Khan Baber
 
Double helix model of dna (kailash)
Double helix model of dna (kailash)Double helix model of dna (kailash)
Double helix model of dna (kailash)
kailash saini
 
DNA structure
DNA structureDNA structure
Various types RNA
Various types RNAVarious types RNA
Various types RNA
gohil sanjay bhagvanji
 
Structure and function of dna
Structure and function of dnaStructure and function of dna
Structure and function of dnaUsmanShahzad1977
 
DNA damage and repair mechanism
DNA damage and repair mechanismDNA damage and repair mechanism
DNA damage and repair mechanism
deepti maheshwari
 
Structure of dna
Structure of dnaStructure of dna
Structure of dna
Ankit Kumar Dubey
 
Nucleic Acids and DNA
Nucleic Acids and DNA Nucleic Acids and DNA
Nucleic Acids and DNA
Garry D. Lasaga
 
Dna the thread of life watson crick model characteristics 2
Dna the thread of life watson crick model characteristics 2Dna the thread of life watson crick model characteristics 2
Dna the thread of life watson crick model characteristics 2
manoj Joshi
 
Basics of DNA Replication
Basics of DNA ReplicationBasics of DNA Replication
Basics of DNA Replication
Riddhi Datta
 
Dna replication
Dna replicationDna replication
Dna replication
naveenagirish
 
DNA structure and it's forms
DNA structure and it's formsDNA structure and it's forms
DNA structure and it's forms
Abid Hussain
 

What's hot (20)

Nucleic acid database
Nucleic acid database Nucleic acid database
Nucleic acid database
 
Dna replication
Dna replicationDna replication
Dna replication
 
DNA Replication
DNA ReplicationDNA Replication
DNA Replication
 
Structure of DNA
Structure of DNAStructure of DNA
Structure of DNA
 
DNA double helix
DNA double helixDNA double helix
DNA double helix
 
Chemistry of DNA
Chemistry of DNAChemistry of DNA
Chemistry of DNA
 
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic material
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic materialNucleic acid and its chemistry - DNA, RNA, DNA as genetic material
Nucleic acid and its chemistry - DNA, RNA, DNA as genetic material
 
DNA & RNA
DNA & RNADNA & RNA
DNA & RNA
 
DNA POLYMERASE
DNA POLYMERASE DNA POLYMERASE
DNA POLYMERASE
 
Double helix model of dna (kailash)
Double helix model of dna (kailash)Double helix model of dna (kailash)
Double helix model of dna (kailash)
 
DNA structure
DNA structureDNA structure
DNA structure
 
Various types RNA
Various types RNAVarious types RNA
Various types RNA
 
Structure and function of dna
Structure and function of dnaStructure and function of dna
Structure and function of dna
 
DNA damage and repair mechanism
DNA damage and repair mechanismDNA damage and repair mechanism
DNA damage and repair mechanism
 
Structure of dna
Structure of dnaStructure of dna
Structure of dna
 
Nucleic Acids and DNA
Nucleic Acids and DNA Nucleic Acids and DNA
Nucleic Acids and DNA
 
Dna the thread of life watson crick model characteristics 2
Dna the thread of life watson crick model characteristics 2Dna the thread of life watson crick model characteristics 2
Dna the thread of life watson crick model characteristics 2
 
Basics of DNA Replication
Basics of DNA ReplicationBasics of DNA Replication
Basics of DNA Replication
 
Dna replication
Dna replicationDna replication
Dna replication
 
DNA structure and it's forms
DNA structure and it's formsDNA structure and it's forms
DNA structure and it's forms
 

Similar to DNA structure, history , definition and double helix model

DNA forms and Structures 0723bh-e-zoo-20.pptx
DNA forms and Structures 0723bh-e-zoo-20.pptxDNA forms and Structures 0723bh-e-zoo-20.pptx
DNA forms and Structures 0723bh-e-zoo-20.pptx
malik830559
 
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptxDNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
JohairahPangadapunMe
 
DNA structure and replication molecular biology
DNA structure and replication molecular biologyDNA structure and replication molecular biology
DNA structure and replication molecular biology
MSGAZAAR1
 
Dna
DnaDna
DNA structure
DNA structureDNA structure
DNA structure
KARTHIK REDDY C A
 
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
BernardoReyMoreno
 
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
AKSHAYMAGAR17
 
DNA strcture and function
DNA strcture and functionDNA strcture and function
DNA strcture and function
vruddhi desai
 
DNA PRESENTATION.pptx
DNA PRESENTATION.pptxDNA PRESENTATION.pptx
DNA PRESENTATION.pptx
Misbahidrees1
 
Nucleic acid..biochem
Nucleic acid..biochemNucleic acid..biochem
Nucleic acid..biochem
dr nainika sharma
 
DNa Deoxyribonucleic acid- code of life
DNa Deoxyribonucleic acid-  code of lifeDNa Deoxyribonucleic acid-  code of life
DNa Deoxyribonucleic acid- code of life
annie160
 
DNA Sequence..pdf
DNA Sequence..pdfDNA Sequence..pdf
DNA Sequence..pdf
NoshiNosheen2
 
Genetics
GeneticsGenetics
Genetics
nobantu pulati
 
STRUCTURE OF DNA.pptx
STRUCTURE OF DNA.pptxSTRUCTURE OF DNA.pptx
STRUCTURE OF DNA.pptx
Santosh Kumar Sahoo
 
Dna Power Point
Dna Power PointDna Power Point
Dna Power Point
patosita
 
Basics of DNA
Basics of DNA Basics of DNA
Basics of DNA
Gauri Jindal
 
Dna structure.jpg
Dna structure.jpgDna structure.jpg
Dna structure.jpg
Praveen Garg
 
DNA STRUCTURE.pptx
DNA STRUCTURE.pptxDNA STRUCTURE.pptx
DNA STRUCTURE.pptx
MaryAnnFrias3
 
Dna (deoxyribonucleic acid) structure and functions
Dna (deoxyribonucleic acid)  structure and functionsDna (deoxyribonucleic acid)  structure and functions
Dna (deoxyribonucleic acid) structure and functions
Namrata Chhabra
 

Similar to DNA structure, history , definition and double helix model (20)

DNA forms and Structures 0723bh-e-zoo-20.pptx
DNA forms and Structures 0723bh-e-zoo-20.pptxDNA forms and Structures 0723bh-e-zoo-20.pptx
DNA forms and Structures 0723bh-e-zoo-20.pptx
 
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptxDNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
DNA STRUCTURE AND INTRODUCTION TO THE REPLICATION.pptx
 
DNA structure and replication molecular biology
DNA structure and replication molecular biologyDNA structure and replication molecular biology
DNA structure and replication molecular biology
 
Dna
DnaDna
Dna
 
DNA structure
DNA structureDNA structure
DNA structure
 
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
CLASE 1 ADN GENERALIDADES.pdfcccccccccccccccccccccccccccccccccccccccccccccccc...
 
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
DNA and RNA , Structure, Functions, Types, difference, Similarities, Protein ...
 
DNA strcture and function
DNA strcture and functionDNA strcture and function
DNA strcture and function
 
DNA structure
DNA structureDNA structure
DNA structure
 
DNA PRESENTATION.pptx
DNA PRESENTATION.pptxDNA PRESENTATION.pptx
DNA PRESENTATION.pptx
 
Nucleic acid..biochem
Nucleic acid..biochemNucleic acid..biochem
Nucleic acid..biochem
 
DNa Deoxyribonucleic acid- code of life
DNa Deoxyribonucleic acid-  code of lifeDNa Deoxyribonucleic acid-  code of life
DNa Deoxyribonucleic acid- code of life
 
DNA Sequence..pdf
DNA Sequence..pdfDNA Sequence..pdf
DNA Sequence..pdf
 
Genetics
GeneticsGenetics
Genetics
 
STRUCTURE OF DNA.pptx
STRUCTURE OF DNA.pptxSTRUCTURE OF DNA.pptx
STRUCTURE OF DNA.pptx
 
Dna Power Point
Dna Power PointDna Power Point
Dna Power Point
 
Basics of DNA
Basics of DNA Basics of DNA
Basics of DNA
 
Dna structure.jpg
Dna structure.jpgDna structure.jpg
Dna structure.jpg
 
DNA STRUCTURE.pptx
DNA STRUCTURE.pptxDNA STRUCTURE.pptx
DNA STRUCTURE.pptx
 
Dna (deoxyribonucleic acid) structure and functions
Dna (deoxyribonucleic acid)  structure and functionsDna (deoxyribonucleic acid)  structure and functions
Dna (deoxyribonucleic acid) structure and functions
 

Recently uploaded

Normal Labour/ Stages of Labour/ Mechanism of Labour
Normal Labour/ Stages of Labour/ Mechanism of LabourNormal Labour/ Stages of Labour/ Mechanism of Labour
Normal Labour/ Stages of Labour/ Mechanism of Labour
Wasim Ak
 
Executive Directors Chat Leveraging AI for Diversity, Equity, and Inclusion
Executive Directors Chat  Leveraging AI for Diversity, Equity, and InclusionExecutive Directors Chat  Leveraging AI for Diversity, Equity, and Inclusion
Executive Directors Chat Leveraging AI for Diversity, Equity, and Inclusion
TechSoup
 
Advantages and Disadvantages of CMS from an SEO Perspective
Advantages and Disadvantages of CMS from an SEO PerspectiveAdvantages and Disadvantages of CMS from an SEO Perspective
Advantages and Disadvantages of CMS from an SEO Perspective
Krisztián Száraz
 
Azure Interview Questions and Answers PDF By ScholarHat
Azure Interview Questions and Answers PDF By ScholarHatAzure Interview Questions and Answers PDF By ScholarHat
Azure Interview Questions and Answers PDF By ScholarHat
Scholarhat
 
Natural birth techniques - Mrs.Akanksha Trivedi Rama University
Natural birth techniques - Mrs.Akanksha Trivedi Rama UniversityNatural birth techniques - Mrs.Akanksha Trivedi Rama University
Natural birth techniques - Mrs.Akanksha Trivedi Rama University
Akanksha trivedi rama nursing college kanpur.
 
Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.
Ashokrao Mane college of Pharmacy Peth-Vadgaon
 
Your Skill Boost Masterclass: Strategies for Effective Upskilling
Your Skill Boost Masterclass: Strategies for Effective UpskillingYour Skill Boost Masterclass: Strategies for Effective Upskilling
Your Skill Boost Masterclass: Strategies for Effective Upskilling
Excellence Foundation for South Sudan
 
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdfMASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
goswamiyash170123
 
clinical examination of hip joint (1).pdf
clinical examination of hip joint (1).pdfclinical examination of hip joint (1).pdf
clinical examination of hip joint (1).pdf
Priyankaranawat4
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
heathfieldcps1
 
Introduction to AI for Nonprofits with Tapp Network
Introduction to AI for Nonprofits with Tapp NetworkIntroduction to AI for Nonprofits with Tapp Network
Introduction to AI for Nonprofits with Tapp Network
TechSoup
 
Digital Artifact 1 - 10VCD Environments Unit
Digital Artifact 1 - 10VCD Environments UnitDigital Artifact 1 - 10VCD Environments Unit
Digital Artifact 1 - 10VCD Environments Unit
chanes7
 
Best Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDABest Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDA
deeptiverma2406
 
Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
Chapter 4 - Islamic Financial Institutions in Malaysia.pptxChapter 4 - Islamic Financial Institutions in Malaysia.pptx
Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
Mohd Adib Abd Muin, Senior Lecturer at Universiti Utara Malaysia
 
What is the purpose of studying mathematics.pptx
What is the purpose of studying mathematics.pptxWhat is the purpose of studying mathematics.pptx
What is the purpose of studying mathematics.pptx
christianmathematics
 
The Diamonds of 2023-2024 in the IGRA collection
The Diamonds of 2023-2024 in the IGRA collectionThe Diamonds of 2023-2024 in the IGRA collection
The Diamonds of 2023-2024 in the IGRA collection
Israel Genealogy Research Association
 
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdfবাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
eBook.com.bd (প্রয়োজনীয় বাংলা বই)
 
How to Build a Module in Odoo 17 Using the Scaffold Method
How to Build a Module in Odoo 17 Using the Scaffold MethodHow to Build a Module in Odoo 17 Using the Scaffold Method
How to Build a Module in Odoo 17 Using the Scaffold Method
Celine George
 
Group Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana BuscigliopptxGroup Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana Buscigliopptx
ArianaBusciglio
 
Reflective and Evaluative Practice PowerPoint
Reflective and Evaluative Practice PowerPointReflective and Evaluative Practice PowerPoint
Reflective and Evaluative Practice PowerPoint
amberjdewit93
 

Recently uploaded (20)

Normal Labour/ Stages of Labour/ Mechanism of Labour
Normal Labour/ Stages of Labour/ Mechanism of LabourNormal Labour/ Stages of Labour/ Mechanism of Labour
Normal Labour/ Stages of Labour/ Mechanism of Labour
 
Executive Directors Chat Leveraging AI for Diversity, Equity, and Inclusion
Executive Directors Chat  Leveraging AI for Diversity, Equity, and InclusionExecutive Directors Chat  Leveraging AI for Diversity, Equity, and Inclusion
Executive Directors Chat Leveraging AI for Diversity, Equity, and Inclusion
 
Advantages and Disadvantages of CMS from an SEO Perspective
Advantages and Disadvantages of CMS from an SEO PerspectiveAdvantages and Disadvantages of CMS from an SEO Perspective
Advantages and Disadvantages of CMS from an SEO Perspective
 
Azure Interview Questions and Answers PDF By ScholarHat
Azure Interview Questions and Answers PDF By ScholarHatAzure Interview Questions and Answers PDF By ScholarHat
Azure Interview Questions and Answers PDF By ScholarHat
 
Natural birth techniques - Mrs.Akanksha Trivedi Rama University
Natural birth techniques - Mrs.Akanksha Trivedi Rama UniversityNatural birth techniques - Mrs.Akanksha Trivedi Rama University
Natural birth techniques - Mrs.Akanksha Trivedi Rama University
 
Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.
 
Your Skill Boost Masterclass: Strategies for Effective Upskilling
Your Skill Boost Masterclass: Strategies for Effective UpskillingYour Skill Boost Masterclass: Strategies for Effective Upskilling
Your Skill Boost Masterclass: Strategies for Effective Upskilling
 
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdfMASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
MASS MEDIA STUDIES-835-CLASS XI Resource Material.pdf
 
clinical examination of hip joint (1).pdf
clinical examination of hip joint (1).pdfclinical examination of hip joint (1).pdf
clinical examination of hip joint (1).pdf
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
 
Introduction to AI for Nonprofits with Tapp Network
Introduction to AI for Nonprofits with Tapp NetworkIntroduction to AI for Nonprofits with Tapp Network
Introduction to AI for Nonprofits with Tapp Network
 
Digital Artifact 1 - 10VCD Environments Unit
Digital Artifact 1 - 10VCD Environments UnitDigital Artifact 1 - 10VCD Environments Unit
Digital Artifact 1 - 10VCD Environments Unit
 
Best Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDABest Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDA
 
Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
Chapter 4 - Islamic Financial Institutions in Malaysia.pptxChapter 4 - Islamic Financial Institutions in Malaysia.pptx
Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
 
What is the purpose of studying mathematics.pptx
What is the purpose of studying mathematics.pptxWhat is the purpose of studying mathematics.pptx
What is the purpose of studying mathematics.pptx
 
The Diamonds of 2023-2024 in the IGRA collection
The Diamonds of 2023-2024 in the IGRA collectionThe Diamonds of 2023-2024 in the IGRA collection
The Diamonds of 2023-2024 in the IGRA collection
 
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdfবাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
 
How to Build a Module in Odoo 17 Using the Scaffold Method
How to Build a Module in Odoo 17 Using the Scaffold MethodHow to Build a Module in Odoo 17 Using the Scaffold Method
How to Build a Module in Odoo 17 Using the Scaffold Method
 
Group Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana BuscigliopptxGroup Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana Buscigliopptx
 
Reflective and Evaluative Practice PowerPoint
Reflective and Evaluative Practice PowerPointReflective and Evaluative Practice PowerPoint
Reflective and Evaluative Practice PowerPoint
 

DNA structure, history , definition and double helix model

  • 2. TODAY WE GO THOUGH THE TOPICS  Structural aspects of DNA  The double helix model  Conformations of DNA
  • 3. QUESTIONS WE COVER  What is DNA ?  Structure of DNA ?  History of DNA?  Types of DNA?  Double helix model of DNA?  Who discovered the DNA?  With what DNA is made up of?
  • 5. DNA  Deoxyribonucleic acid, or DNA, is a molecule that contains the instructions an organism needs to develop, live and reproduce.  These instructions are found inside every cell, and are passed down from parents to their children.  Its one long molecule that contains our genetic ‘code’.
  • 6. DEFINITION OF DNA  Deoxyribonucleic acid is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms many viruses.  It is a carrier of all genetic information.  DNA and RNA are nucleic acids.
  • 7. HISTORY OF DNA  Many people believe that American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950’s. In reality, this is not the case. Rather, DNA was first identified in the late 1860’s by Swiss chemist Friedrich Miescher.  The discovery in 1953 of the double helix, the twisted- ladder structure of deoxyribonucleic acid(DNA), by James Watson and Francis Crick marked a milestone in the history of science and gave rise to modern molecular biology, which is largely concerned with understanding how genes control the chemical processes.
  • 8.
  • 9. STRUCTURE OF DNA  DNA is made up of molecules known as nucleotides.  Each nucleotide contains a sugar and phosphate group as well as nitrogen bases.  These nitrogen bases are further broken down into four types, including • Adenine (A) • Cytosine (C) • Guanine (G) • Thymine (T)
  • 10.  DNA’s structure is a double stranded helix, and it resembles the look of a twisted ladder.  The sugar and phosphates are nucleotide strands that form the long sides.  The nitrogen bases are rungs.  Every rung is actually two types of nitrogen bases that pair together to form a complete rung and hold the long strands of nucleotides together.  Remember, there are four types of nitrogen bases, and they pair together specifically-adrenaline pairs with thymine, and guanine with cytosine.  T=A AND G=C
  • 12.
  • 13.
  • 14.
  • 15. • Human DNA is unique in that it is made up of nearly 3 billion base pairs, and about 99 percent of them are the same in every human. • However, it’s the sequence of these bases that determines what information is available to both build and maintain any organism.
  • 16. DOUBLE HELIX STRUCTURE  Double helix is the description of the structure of a DNA molecule.  A DNA molecule consists of two strands that wind each other like a twisted ladder.  Each strand has a backbone made of alternating groups of sugar(de- oxy-ribose) and phosphate groups.  Attached to each sugar is one of four bases: adenine(A), cytosine(C), guanine(G), or thymine(T).  The two strands are held together by bonds between the bases, adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.
  • 18. CONFORMATIONS OF DNA  The different types of DNA are: • B-DNA • A-DNA • Z-DNA • C-DNA • D-DNA • E-DNA
  • 19. B-DNA  B-form DNA is a right handed double helix, which was discovered by Watson and crick based on the x- ray patterns.  It is the common form of DNA exists under normal physiological condition.  The double strands of B-DNA run in opposite directions.  Most common, originally deduced from X-ray diffraction of sodium salt of DNA fibers at 92% relative humidity.  DNA molecule consists of 2 helical polynucleotide chains coiled around common axis.  The 2 chains run in opposite direction, they are antiparallel, the plane of bases are perpendicular to helix axis. Complementary base pairing.  The grooves provide surface with which proteins, chemicals, drugs can interact.  The proteins access genetic information easily through the major groove of B-DNA.( So it is more stable).
  • 20. A-DNA  A-form DNA is a right handed double helix, which was discovered by Rosalind franklin, who was named the A and B forms.  A-DNA originally identified by X-ray diffraction of analysis of DNA fibers at 75% relative humidity.  Occur only in dehydrated sample of DNA, such those used in crystallographic experiments.  It is one of possible double helical structure which DNA can adopt along with other two biological active helix structure.(B-DNA,Z- DNA)  Short and fat compared B-DNA.  The bases are not tilted and are grooves are also not as deep as B-DNA.
  • 21. Z-DNA  It is a left handed double helix structure winds to left in zig-zag manner.so they termed as Z-DNA.  It is discovered by Rich, Nordheim &Wang in 1984  It has antiparallel strands as DNA and it is long and thin compared to B-DNA  Adjacent sugar have alternating orientation. And has one deep helical groove  Z-DNA has both purines and Pyramidines.  purines has Syn conformation (bases & sugar are near and on same side).  Pyramidines has anti conformation ( bases & sugar are distant and on opposite sides).
  • 22.
  • 23.
  • 24. C-DNA, D-DNA, AND E-DNA ARE THE FORMS OF DNA. A-DNA, B-DNA AND Z- DNA ARE THE TYPES OF DNA.
  • 25. C-DNA  It is often used to clone eukaryotic genes in prokaryotes.  C-DNA has it’s own significance in PCR technique.  C-DNA strands for complementary DNA.  It is synthesized from a single-stranded RNA.  It is formed at 66% relative humidity and in presence of Li+ and Mg2+.  It is a right handed DNA.  It has smaller diameter than that of A- DNA and B-DNA.
  • 26. D-DNA  It is a rare variant with 8 base pairs per helical turn.  These forms of DNA found in some DNA molecules devoid of guanine.  The tilt of 16.7° from the axis of the helix.  The axis rise of 3.03A° per base pairs.  Actually 2 different forms of D-DNA. • D(A): takes part in D-A-B transition. • D(B): associated with D-B change of conformation.
  • 27. E-dna  Extended or eccentric DNA.  E-DNA has a long helical axis rise and base perpendicular to the helical axis.  E-DNA allowed to crystallize for a period time longer, the methylated sequence forms standard A-DNA.  E-DNA is the intermediate in the crystallographic pathway from B- DNA to A-DNA.