DNA is a double-helix molecule that carries genetic instructions. It is composed of two strands of polynucleotides made up of nucleotides, each containing a nitrogenous base, sugar, and phosphate. The strands are stabilized by hydrogen bonds between complementary bases and base-stacking interactions. DNA can be denatured into single strands by elevated temperature, extreme pH, low salt concentrations, or chemicals that disrupt hydrogen bonding between strands. Denaturation temperature depends on factors like base composition and length. Renaturation occurs when double-stranded DNA is cooled under conditions that allow the strands to re-form hydrogen bonds and complementary base pairing.
Watson and Crick proposed a model of DNA structure in 1953 as a double helix with two antiparallel strands coiled around the same axis. Each strand consists of alternating deoxyribose and phosphate groups with purine or pyrimidine bases stacked inside. Adenine always pairs with thymine via two hydrogen bonds and guanine pairs with cytosine via three hydrogen bonds. Their model explained experimental X-ray diffraction data and Chargaff's rules of base equivalence. The discovery revolutionized our understanding of genetics and heredity.
The document discusses three models of DNA replication:
1) Asymmetric replication - the leading and lagging strands are replicated differently due to the 5' to 3' directionality of DNA polymerase. The leading strand replicates continuously while the lagging strand replicates discontinuously in short Okazaki fragments.
2) D-loop model - replication in mitochondria where one strand is displaced to form a D-loop and replicates first before the other strand.
3) Rolling circle model - used by plasmids and viruses where one strand is nicked and displaced to be used as a template, forming multiple copies linked together in a concatemer.
Meselson and Stahl conducted an experiment using E. coli bacteria to test the hypothesis that DNA replicates semi-conservatively. They grew the bacteria in medium containing a heavy isotope of nitrogen, then switched the bacteria to medium with a light isotope. Analysis of DNA densities over multiple generations provided evidence that DNA replication results in one old strand and one new strand in each daughter molecule, supporting the semi-conservative model.
There are three main forms of DNA structure: A-DNA, B-DNA, and Z-DNA. B-DNA is the most common form found under physiological conditions, having a right-handed double helix with 10.5 base pairs per turn. A-DNA forms under dehydrating conditions and has a wider helix with 11 base pairs per turn. Z-DNA is a left-handed helix that forms with alternating purine-pyrimidine sequences, containing 12 base pairs per turn in a narrow, zig-zag structure. While B-DNA is most prevalent, the structure can vary depending on sequence and environmental conditions.
DNA topology studies the geometric properties and spatial relationships of DNA that are unaffected by changes in shape or size. It includes phenomena like supercoiling, knots, and catenanes that involve the linking and twisting of the two DNA strands. DNA topology is characterized by parameters like the linking number, which represents the number of times the two strands are twisted around each other. Enzymes called topoisomerases regulate DNA topology by introducing temporary breaks in the DNA strands to allow strand passage and control supercoiling levels.
The following slides contains a brief comparison of the different forms of the DNA. It includes A-DNA, B-DNA , and Z-DNA.
It also briefs about the conditions that would favor the transition from one form to the another
Topoisomerases are enzymes that alter the supercoiling of DNA by transiently cutting one or both strands of DNA. There are two main types of topoisomerases. Type 1 enzymes remove supercoils by breaking a single DNA strand, while Type 2 enzymes break both strands simultaneously. The regulation of DNA supercoiling by topoisomerases is essential for DNA transcription and replication to occur as it allows unwinding of the DNA helix. Bacteria contain DNA gyrase as their Type 2 topoisomerase, while eukaryotes contain multiple topoisomerase enzymes that can introduce or remove both positive and negative supercoils. Topoisomerases are important drug targets, with inhibitors of bacterial gyrase
DNA is a double-helix molecule that carries genetic instructions. It is composed of two strands of polynucleotides made up of nucleotides, each containing a nitrogenous base, sugar, and phosphate. The strands are stabilized by hydrogen bonds between complementary bases and base-stacking interactions. DNA can be denatured into single strands by elevated temperature, extreme pH, low salt concentrations, or chemicals that disrupt hydrogen bonding between strands. Denaturation temperature depends on factors like base composition and length. Renaturation occurs when double-stranded DNA is cooled under conditions that allow the strands to re-form hydrogen bonds and complementary base pairing.
Watson and Crick proposed a model of DNA structure in 1953 as a double helix with two antiparallel strands coiled around the same axis. Each strand consists of alternating deoxyribose and phosphate groups with purine or pyrimidine bases stacked inside. Adenine always pairs with thymine via two hydrogen bonds and guanine pairs with cytosine via three hydrogen bonds. Their model explained experimental X-ray diffraction data and Chargaff's rules of base equivalence. The discovery revolutionized our understanding of genetics and heredity.
The document discusses three models of DNA replication:
1) Asymmetric replication - the leading and lagging strands are replicated differently due to the 5' to 3' directionality of DNA polymerase. The leading strand replicates continuously while the lagging strand replicates discontinuously in short Okazaki fragments.
2) D-loop model - replication in mitochondria where one strand is displaced to form a D-loop and replicates first before the other strand.
3) Rolling circle model - used by plasmids and viruses where one strand is nicked and displaced to be used as a template, forming multiple copies linked together in a concatemer.
Meselson and Stahl conducted an experiment using E. coli bacteria to test the hypothesis that DNA replicates semi-conservatively. They grew the bacteria in medium containing a heavy isotope of nitrogen, then switched the bacteria to medium with a light isotope. Analysis of DNA densities over multiple generations provided evidence that DNA replication results in one old strand and one new strand in each daughter molecule, supporting the semi-conservative model.
There are three main forms of DNA structure: A-DNA, B-DNA, and Z-DNA. B-DNA is the most common form found under physiological conditions, having a right-handed double helix with 10.5 base pairs per turn. A-DNA forms under dehydrating conditions and has a wider helix with 11 base pairs per turn. Z-DNA is a left-handed helix that forms with alternating purine-pyrimidine sequences, containing 12 base pairs per turn in a narrow, zig-zag structure. While B-DNA is most prevalent, the structure can vary depending on sequence and environmental conditions.
DNA topology studies the geometric properties and spatial relationships of DNA that are unaffected by changes in shape or size. It includes phenomena like supercoiling, knots, and catenanes that involve the linking and twisting of the two DNA strands. DNA topology is characterized by parameters like the linking number, which represents the number of times the two strands are twisted around each other. Enzymes called topoisomerases regulate DNA topology by introducing temporary breaks in the DNA strands to allow strand passage and control supercoiling levels.
The following slides contains a brief comparison of the different forms of the DNA. It includes A-DNA, B-DNA , and Z-DNA.
It also briefs about the conditions that would favor the transition from one form to the another
Topoisomerases are enzymes that alter the supercoiling of DNA by transiently cutting one or both strands of DNA. There are two main types of topoisomerases. Type 1 enzymes remove supercoils by breaking a single DNA strand, while Type 2 enzymes break both strands simultaneously. The regulation of DNA supercoiling by topoisomerases is essential for DNA transcription and replication to occur as it allows unwinding of the DNA helix. Bacteria contain DNA gyrase as their Type 2 topoisomerase, while eukaryotes contain multiple topoisomerase enzymes that can introduce or remove both positive and negative supercoils. Topoisomerases are important drug targets, with inhibitors of bacterial gyrase
Translation in prokaryotes involves three main stages - initiation, elongation, and termination. During initiation, the small ribosomal subunit binds to an mRNA with help from initiation factors and forms the initiation complex. In elongation, tRNAs bring amino acids to the ribosome according to mRNA codons and peptide bonds are formed. Termination occurs when a stop codon signals for the release of the complete polypeptide from the ribosome. The process requires several RNA and protein molecules working together, including ribosomes, tRNAs, and various factors, to translate the genetic message into a polypeptide product.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
Secondary Structure Of Protein (Repeating structure of protein)Amrutha Hari
This document discusses the structure of proteins at various levels. It describes the primary, secondary, tertiary, and quaternary structures. The secondary structures discussed in detail include the alpha helix, beta pleated sheet, random coil, collagen helix, and beta turn. The alpha helix and beta pleated sheet are stabilized by hydrogen bonding between amino acids. The collagen helix structure provides strength and is the main component of connective tissues. Genetic disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta result from defects in collagen structures. Ramachandran plots are used to visualize allowed backbone dihedral angles in protein structures.
This document discusses the C-Value Paradox, which is the observation that there is no correlation between the complexity of an organism and the amount of DNA (C-value) in its genome. The document provides examples showing that C-values, or the amount of DNA per haploid cell, can vary widely both within and across species, from 105 base pairs in mycoplasma to over 109 base pairs in mammals. While complexity tends to increase with higher C-values, exceptions exist, demonstrating there is no direct linear relationship between genome size and organism complexity. The term "C-value" refers to the haploid DNA content of a species.
This document discusses restriction enzymes, including their discovery, types, subunits, nomenclature, recognition sequences, properties, and applications. Restriction enzymes are bacterial enzymes that cut DNA at specific recognition sequences. There are three main types - Type I cut DNA randomly, Type II cut within or near their recognition sequences, and Type III cut nearby. They are used in gene cloning, protein expression, DNA manipulation, and studying DNA sequences.
The document discusses DNA denaturation and renaturation, including:
- Denaturation involves unwinding the DNA double helix into single strands through heating or chemical treatment, disrupting hydrogen bonds between base pairs. This increases UV absorption.
- Renaturation is the spontaneous rewinding of single strands back into the original double helix structure when denaturing conditions are removed, through base pairing of complementary strands.
- C0t curves plot the fraction of single strands renatured versus the product of DNA concentration and time, and can indicate the complexity and size of the original DNA sample based on renaturation rates. More complex DNA with more dissimilar sequences takes longer to renature
The document discusses DNA binding proteins. It describes how DNA is wrapped around histone proteins to form nucleosomes, which resemble "beads on a string". There are five main types of histone proteins - H1, H2A, H2B, H3, and H4. Histone proteins can be modified through processes like acetylation and methylation, which affect gene expression. Other non-histone proteins use motifs like zinc fingers and helix-turn-helix to bind DNA in a sequence-specific manner and regulate transcription.
Histone proteins package DNA into nucleosomes and facilitate chromatin formation. There are two main classes of histones - core histones like H2A, H2B, H3, and H4 which assemble around DNA, and linker histone H1 which binds nucleosomes. Post-translational modifications of histone tails like acetylation and methylation regulate gene expression by altering chromatin structure. Genomic imprinting is an epigenetic process where gene expression depends on parental origin through histone modifications and other epigenetic markers without changing DNA sequence.
Restriction enzymes are molecular scissors found in bacteria that cut DNA molecules at specific recognition sequences. They serve as a defensive mechanism for bacteria against bacteriophages by cleaving the phage DNA. There are over 3000 known restriction enzymes that are classified into four main types based on their composition, cofactors, and cutting mechanisms. Restriction enzymes are important tools in biotechnology for manipulating DNA sequences through cutting DNA fragments with specific sticky or blunt ends, which can then be recombined through techniques like cloning.
DNA polymerases are a group of enzymes that are used to make copies of DNA templates, essentially used in DNA replication mechanisms. These enzymes make new copies of DNA from existing templates and also function by repairing the synthesized DNA to prevent mutations. DNA polymerase catalyzes the formation of the phosphodiester bond which makes up the backbone of DNA molecules. It uses a magnesium ion in catalytic activity to balance the charge from the phosphate group.
The document discusses the Ramachandran plot, which shows statistically probable combinations of the phi and psi backbone torsion angles in proteins. It describes how these two angles describe rotations around bonds in the polypeptide backbone and influence protein folding. The plot reveals allowed and disallowed regions based on steric clashes between atoms at different angle combinations. Common structures like alpha helices and beta sheets correspond to allowed regions in the plot.
The document discusses genome organization in eukaryotes. It begins by defining the genome as an organism's entire hereditary information, encoded in DNA or RNA. In eukaryotes, DNA is associated with histone proteins to form chromatin fibers, which condense into chromosomes. The document then discusses various levels of chromatin organization, from DNA wrapping around nucleosomes to form beads on a string, to higher-order folding forming metaphase chromosomes. Chromatin exists in two types - loosely packed euchromatin and tightly packed heterochromatin. Overall, the document provides an overview of eukaryotic genome and chromatin organization from nucleosomes to chromosomes.
DNA replication is the process by which DNA copies itself in living cells. It occurs in three main steps: initiation, elongation, and termination. Initiation begins at origins of replication, where proteins assemble into pre-replication complexes. During elongation, helicase unwinds the DNA strands and DNA polymerase adds complementary nucleotides to each strand. Termination occurs when the replication forks meet, with telomerase ensuring complete replication of chromosome ends.
Genetic recombination involves the breaking and rejoining of DNA to form new combinations of genes. It occurs primarily during meiosis through several types of recombination, including homologous recombination where DNA exchanges occur between similar DNA molecules. This increases genetic diversity and allows for traits to be mixed. Recombination benefits populations by generating variety among offspring and allowing deleterious genes to be removed without losing the entire chromosome. It has applications in cloning, mapping genes, and making transgenic organisms.
1) Griffith discovered a "transforming principle" that allowed non-virulent bacteria to become virulent after exposure to heat-killed virulent bacteria.
2) Avery, MacLeod, and McCarty determined that the transforming principle was DNA through experiments treating components with DNAses, RNAses, and proteases.
3) Hershey and Chase provided definitive evidence that DNA is the genetic material through experiments using bacteriophages containing radioactive DNA or protein to infect bacteria, showing that only DNA was transferred.
This document discusses transcription in eukaryotes. It begins with definitions of transcription and describes the basic process of RNA being synthesized from a DNA template. It then covers the mechanisms of transcription, including initiation involving RNA polymerase and transcription factors, elongation, and termination. The key similarities between prokaryotic and eukaryotic transcription are that DNA acts as a template and RNA polymerase facilitates RNA synthesis. Key differences are that eukaryotic transcription occurs in the nucleus, is carried out by three classes of RNA polymerase, and RNAs are processed in the nucleus rather than the cytoplasm.
This document provides an overview of DNA structure and properties. It discusses the discovery of DNA's double helix structure by Watson and Crick in 1953. It also describes the types of DNA (nuclear and mitochondrial), forms of DNA structure (A, B, and Z forms), and functions of DNA including storing genetic information and directing protein synthesis. Recent research discussed in the document found that peculiar Retron structures in bacteria act as "guards" for the bacterial immune system when infected by viruses.
The document discusses different forms of DNA structure that can be adopted based on environmental conditions. The main forms discussed are B-DNA, A-DNA, Z-DNA, C-DNA, D-DNA and E-DNA. B-DNA is the most common form, having a right-handed double helix structure with 10 base pairs per turn. A-DNA and Z-DNA are also double helical but have different structural characteristics than B-DNA such as base pair spacing and groove size. The various forms arise in response to changes in humidity, ionic conditions and DNA sequence composition.
Translation in prokaryotes involves three main stages - initiation, elongation, and termination. During initiation, the small ribosomal subunit binds to an mRNA with help from initiation factors and forms the initiation complex. In elongation, tRNAs bring amino acids to the ribosome according to mRNA codons and peptide bonds are formed. Termination occurs when a stop codon signals for the release of the complete polypeptide from the ribosome. The process requires several RNA and protein molecules working together, including ribosomes, tRNAs, and various factors, to translate the genetic message into a polypeptide product.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
Secondary Structure Of Protein (Repeating structure of protein)Amrutha Hari
This document discusses the structure of proteins at various levels. It describes the primary, secondary, tertiary, and quaternary structures. The secondary structures discussed in detail include the alpha helix, beta pleated sheet, random coil, collagen helix, and beta turn. The alpha helix and beta pleated sheet are stabilized by hydrogen bonding between amino acids. The collagen helix structure provides strength and is the main component of connective tissues. Genetic disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta result from defects in collagen structures. Ramachandran plots are used to visualize allowed backbone dihedral angles in protein structures.
This document discusses the C-Value Paradox, which is the observation that there is no correlation between the complexity of an organism and the amount of DNA (C-value) in its genome. The document provides examples showing that C-values, or the amount of DNA per haploid cell, can vary widely both within and across species, from 105 base pairs in mycoplasma to over 109 base pairs in mammals. While complexity tends to increase with higher C-values, exceptions exist, demonstrating there is no direct linear relationship between genome size and organism complexity. The term "C-value" refers to the haploid DNA content of a species.
This document discusses restriction enzymes, including their discovery, types, subunits, nomenclature, recognition sequences, properties, and applications. Restriction enzymes are bacterial enzymes that cut DNA at specific recognition sequences. There are three main types - Type I cut DNA randomly, Type II cut within or near their recognition sequences, and Type III cut nearby. They are used in gene cloning, protein expression, DNA manipulation, and studying DNA sequences.
The document discusses DNA denaturation and renaturation, including:
- Denaturation involves unwinding the DNA double helix into single strands through heating or chemical treatment, disrupting hydrogen bonds between base pairs. This increases UV absorption.
- Renaturation is the spontaneous rewinding of single strands back into the original double helix structure when denaturing conditions are removed, through base pairing of complementary strands.
- C0t curves plot the fraction of single strands renatured versus the product of DNA concentration and time, and can indicate the complexity and size of the original DNA sample based on renaturation rates. More complex DNA with more dissimilar sequences takes longer to renature
The document discusses DNA binding proteins. It describes how DNA is wrapped around histone proteins to form nucleosomes, which resemble "beads on a string". There are five main types of histone proteins - H1, H2A, H2B, H3, and H4. Histone proteins can be modified through processes like acetylation and methylation, which affect gene expression. Other non-histone proteins use motifs like zinc fingers and helix-turn-helix to bind DNA in a sequence-specific manner and regulate transcription.
Histone proteins package DNA into nucleosomes and facilitate chromatin formation. There are two main classes of histones - core histones like H2A, H2B, H3, and H4 which assemble around DNA, and linker histone H1 which binds nucleosomes. Post-translational modifications of histone tails like acetylation and methylation regulate gene expression by altering chromatin structure. Genomic imprinting is an epigenetic process where gene expression depends on parental origin through histone modifications and other epigenetic markers without changing DNA sequence.
Restriction enzymes are molecular scissors found in bacteria that cut DNA molecules at specific recognition sequences. They serve as a defensive mechanism for bacteria against bacteriophages by cleaving the phage DNA. There are over 3000 known restriction enzymes that are classified into four main types based on their composition, cofactors, and cutting mechanisms. Restriction enzymes are important tools in biotechnology for manipulating DNA sequences through cutting DNA fragments with specific sticky or blunt ends, which can then be recombined through techniques like cloning.
DNA polymerases are a group of enzymes that are used to make copies of DNA templates, essentially used in DNA replication mechanisms. These enzymes make new copies of DNA from existing templates and also function by repairing the synthesized DNA to prevent mutations. DNA polymerase catalyzes the formation of the phosphodiester bond which makes up the backbone of DNA molecules. It uses a magnesium ion in catalytic activity to balance the charge from the phosphate group.
The document discusses the Ramachandran plot, which shows statistically probable combinations of the phi and psi backbone torsion angles in proteins. It describes how these two angles describe rotations around bonds in the polypeptide backbone and influence protein folding. The plot reveals allowed and disallowed regions based on steric clashes between atoms at different angle combinations. Common structures like alpha helices and beta sheets correspond to allowed regions in the plot.
The document discusses genome organization in eukaryotes. It begins by defining the genome as an organism's entire hereditary information, encoded in DNA or RNA. In eukaryotes, DNA is associated with histone proteins to form chromatin fibers, which condense into chromosomes. The document then discusses various levels of chromatin organization, from DNA wrapping around nucleosomes to form beads on a string, to higher-order folding forming metaphase chromosomes. Chromatin exists in two types - loosely packed euchromatin and tightly packed heterochromatin. Overall, the document provides an overview of eukaryotic genome and chromatin organization from nucleosomes to chromosomes.
DNA replication is the process by which DNA copies itself in living cells. It occurs in three main steps: initiation, elongation, and termination. Initiation begins at origins of replication, where proteins assemble into pre-replication complexes. During elongation, helicase unwinds the DNA strands and DNA polymerase adds complementary nucleotides to each strand. Termination occurs when the replication forks meet, with telomerase ensuring complete replication of chromosome ends.
Genetic recombination involves the breaking and rejoining of DNA to form new combinations of genes. It occurs primarily during meiosis through several types of recombination, including homologous recombination where DNA exchanges occur between similar DNA molecules. This increases genetic diversity and allows for traits to be mixed. Recombination benefits populations by generating variety among offspring and allowing deleterious genes to be removed without losing the entire chromosome. It has applications in cloning, mapping genes, and making transgenic organisms.
1) Griffith discovered a "transforming principle" that allowed non-virulent bacteria to become virulent after exposure to heat-killed virulent bacteria.
2) Avery, MacLeod, and McCarty determined that the transforming principle was DNA through experiments treating components with DNAses, RNAses, and proteases.
3) Hershey and Chase provided definitive evidence that DNA is the genetic material through experiments using bacteriophages containing radioactive DNA or protein to infect bacteria, showing that only DNA was transferred.
This document discusses transcription in eukaryotes. It begins with definitions of transcription and describes the basic process of RNA being synthesized from a DNA template. It then covers the mechanisms of transcription, including initiation involving RNA polymerase and transcription factors, elongation, and termination. The key similarities between prokaryotic and eukaryotic transcription are that DNA acts as a template and RNA polymerase facilitates RNA synthesis. Key differences are that eukaryotic transcription occurs in the nucleus, is carried out by three classes of RNA polymerase, and RNAs are processed in the nucleus rather than the cytoplasm.
This document provides an overview of DNA structure and properties. It discusses the discovery of DNA's double helix structure by Watson and Crick in 1953. It also describes the types of DNA (nuclear and mitochondrial), forms of DNA structure (A, B, and Z forms), and functions of DNA including storing genetic information and directing protein synthesis. Recent research discussed in the document found that peculiar Retron structures in bacteria act as "guards" for the bacterial immune system when infected by viruses.
The document discusses different forms of DNA structure that can be adopted based on environmental conditions. The main forms discussed are B-DNA, A-DNA, Z-DNA, C-DNA, D-DNA and E-DNA. B-DNA is the most common form, having a right-handed double helix structure with 10 base pairs per turn. A-DNA and Z-DNA are also double helical but have different structural characteristics than B-DNA such as base pair spacing and groove size. The various forms arise in response to changes in humidity, ionic conditions and DNA sequence composition.
B-DNA, Z-DNA, A-DNA, stability of dsDNA helix, DNA denaturation, factors affecting Tm ,GC content, ionic strength, DNA as a genetic material, Griffith’s experiment, Hershey-chase experiment
The document discusses the identification of DNA as the genetic material. It describes Griffith's transformation experiments in 1928 which showed that something from dead bacterial cells was transforming live bacterial cells. Avery, MacLeod and McCarty in 1944 identified that this transforming principle was DNA. Their experiments showed that only extracts containing purified DNA were able to transform bacterial cells, establishing DNA as the genetic material. The document also discusses the work of Chargaff, Hershey and Chase, and others that provided further evidence supporting DNA as the carrier of genetic information.
History of DNA. introduction of DNA with short history and findings. different types of DNA with structures variations. A -DNA, B- DNA, C- DNA E- DNA D- DNA And Z DNA Detail information of these DNA with their comparison tables, different types of unusual DNA and sequences. Functions of DNA with their explanations . Nucleic acid chemical basis : Denaturation and annealing of DNA with factors for that. New DNA.
The document provides information on the structure of DNA and RNA. It discusses how DNA was discovered to have a double helix structure by Watson and Crick in 1953 based on prior work by scientists like Franklin, Wilkins, Chargaff and Pauling. It describes the key components of DNA including the sugar-phosphate backbone, nitrogenous bases, and how the bases pair up in the double helix structure. It also discusses different DNA structures like A, B and Z-DNA and how DNA packages into nucleosomes and chromosomes. For RNA, it notes that it is similar to DNA but contains the sugar ribose and base uracil instead of thymine.
This power point presentation explains double helical structure of DNA as proposed by Watson and Crick (1953).Attempts have also been made to high light the valuable contributions made by Rosalind Franklin and Wilkins. Brief details of different types of DNA have also been included.
The document provides a history of discoveries related to DNA structure and function. Some key points summarized:
1) In the 1800s, nucleic acids were discovered but their role was unknown. In the 1950s, experiments showed that DNA was the transforming principle that carried genetic information.
2) In 1953, Watson and Crick proposed the double helix structure of DNA, with base pairing of A-T and G-C. This explained prior findings on base ratios by Chargaff.
3) DNA contains the genetic code as a sequence of nucleotide bases that provides instructions for protein synthesis and cell function. Its double helix structure allows for replication and transmission of genetic material from parent to daughter cells.
The document provides a history of discoveries related to DNA. Some key points summarized:
1) In the 1800s, nucleic acids were discovered but their role was unknown. In 1928, Griffith discovered a transforming principle in bacteria, later identified as DNA. In 1953, Watson and Crick proposed the double helix structure of DNA.
2) The double helix structure explained the previous findings of Chargaff who discovered base pairing ratios and Franklin's X-ray crystallography. Watson and Crick's model showed DNA was made of two anti-parallel strands with specific base pairing of A-T and C-G.
3) DNA functions to store and transfer genetic information through its base sequence, allowing
DNA- deoxyribonucleic acid
A long molecule that looks like a twisted ladder made up of four types of simple units and the sequence of these units carries genetic information.
Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).
Nucleic acids are polymers of nucleotides held together by phosphate bridges that serve as the genetic material of organisms. There are two main types: DNA and RNA. DNA is found in the nucleus and functions to store and transmit genetic information through its double helix structure. It is made of deoxyribonucleotides and follows Chargaff's rules of equal base pairing. RNA is involved in protein synthesis and certain cellular functions. Both nucleic acids maintain hereditary traits and cellular functions through their roles in gene expression and protein production.
The document discusses the structure and polymorphism of DNA. It describes how DNA is composed of two polynucleotide chains that form a double helix structure. The chains are held together by bonds between complementary nucleotide base pairs of adenine-thymine and guanine-cytosine. DNA can take on different helical structures, including A-DNA, B-DNA, and Z-DNA forms. A-DNA is a right-handed helix found in dehydrated DNA. B-DNA is the most common right-handed form with a 10.5 base pair turn. Z-DNA is a left-handed helix favored by alternating purine-pyrimidine sequences.
DNA contains genetic information stored in genes that code for proteins. It self-replicates and uses RNA to synthesize proteins involved in all body processes. DNA interacts with drugs that can bind covalently or non-covalently. Minor groove binders fit in the DNA minor groove and form hydrogen bonds. Intercalators insert between DNA base pairs and stack via pi-pi interactions. Understanding drug-DNA binding forces like charge compensation and structural changes aids drug design for therapeutic applications.
welcome to lovyansh lifescience
topic of molecular biology The Structure of DNA for csir net lifescience 2022 june
DNA Is Composed of Polynucleotide Chains
Base tautomers
nucleotide
nucleoside.
FORMATION OF NUCLEOTIDE & NUCLEOSIDE
Watson base pairing
The Double Helix Has Minor and Major Grooves
Chemical groups exposed in the major and minor grooves along the edges
of the base pairs
Models of the B, A, and Z forms of DNA.
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This document provides information about DNA structure and types. It begins with a timeline of important discoveries in DNA research. It then discusses the primary and secondary structures of DNA, including the double helix model proposed by Watson and Crick. It describes Chargaff's rules and the complementary base pairing of A-T and G-C. Finally, it summarizes the different forms of DNA like A, B, and Z-DNA and discusses mitochondrial DNA and unusual DNA sequences.
Types of DNA and RNA and their importancePankaj Gami
This document provides information on different types of DNA and RNA:
1. It discusses the key discoveries of DNA's double helix structure by Watson and Crick in 1953 and describes the complementary base pairing of A=T and C=G.
2. It describes the different conformations that DNA can take including B-DNA, Z-DNA, A-DNA, C-DNA, D-DNA, and E-DNA and compares their characteristics.
3. It explains the three main types of DNA tested by ancestry services - paternal Y-DNA, maternal mtDNA, and autosomal DNA - and how each can be used to trace direct paternal, maternal, or recent lineages.
This document provides information on molecular biology and nucleic acids. It discusses the central dogma of life, the types and structures of DNA and RNA, and the differences between DNA and RNA. It also summarizes the three major types of DNA structures (A-form, B-form, and Z-form DNA), describes the central dogma process, and explains the hydrolysis of nucleic acids through denaturation and renaturation.
At this time; reading, listening or writing the word DNA doesn’t amaze us, we know that it is deoxyribonucleic acid. But it was not always like this. There was a time when it was a mystery; many of the scientists, researcher and workers spent their whole life in searching out what is DNA.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
8.Isolation of pure cultures and preservation of cultures.pdf
Major and minor grooves dna
1. ASSIGNMENT
on
MAJOR ANDMINOR GROOVES OF DNA
Submitted To: Submitted By:
Dr. D.K. Garg Smrutishree Sahoo
Professor M.Sc.(Ag.) PBG Previous
Department of PLANT BREEDING AND GENETICS
College of Agriculture
Swami Keshwanand Rajasthan Agricultural University, Bikaner
2.
3. James D. Watson & Francis H. Crick
In 1953 presented the double Helix model of DNA
Two primary sources of information:
1. Chargaff Rule: #A#T and #G#C.
2. X-ray diffraction studies of Rosalind Franklin & Maurice
H. F. Wilkins.
4.
5. The Two Grooves of DNA
A DNA has two grooves i.e. Major
and Minor groove.
Grooves are not equal size and
opposite to each other.
Simple consequences of Different
geometry of the base pair results
grooves.
Larger is Major groove
Smaller is Minor groove
Major groove occupied by many
water molecule than the minor
grooves
6. Each base pair rotated in 36 ˚around the axis
10 base pairs rotated in 360˚ makes a complete turn.
Twisting of the two strands around one another forms a
double helix with a minor groove with 12A˚ across and a
major groove with 22A˚ across .
Angle at which the sugar protrude out from the base
pair(i.e. angle between Glycosidic bond) is 120˚ or 240˚.
Major Groove - 240˚
Minor Groove - 120˚
9. A-DNA has a shallow minor groove and a deep major groove:-
B-DNA A-DNA
10. FEATURES OF GROOVES
The characteristic patterns of H-bond and of overall shape
that are exposed in major groove distinguishes an A:T from
G:C, A:T from T:A and G:C from C:G.
from the chemical information of the contents of major
groove we can distinguish the base pairs.
Ex- ADAM in A:T and MADA in T:A
AADH in G:C and HDAA in C:G
11. A:T PAIR
Large angle of MAJOR GROOVES
contain following structures-
A hydrogen bond acceptor (N7 of
Adenine)
A H-bond donor(Amino group on
C6 of Adenine)
A H-bond acceptor (Carbonyl
group on Thymine)
A hydrophobic surface(Methyl
group on C5 Thymine)
MINOR GROOVE has
Two H-bond Acceptor
One H-atom
13. G:C pair
MAJOR GROOVES-
A H-bond acceptor(N7 of
guanine)
A H-bond acceptor(carbonyl
group on C6 guanine)
A H-bond donor (amino group
on C4 of Cytosine)
A small nonpolar hydrogen( C5
of cytosine)
MINOR GROOVES-
2 H-bond acceptor
1 H-bond donor
15. DNA BINDING PROTEINS:-
Expression of the biological phenomenon in a genome
mediated by a DNA binding protein.
These proteins attach to the double helix in a specific site
and regulate the gene activity.
Major groove is rich in chemical information that's why
most of the DNA binding proteins bind with major groove.
The DNA sequence can be read without the helix being
opened up by breaking the base pairs.
16. 2 types:-
SPECIFIC - The region is particular, so bind to major
grooves only.
Ex-Transcription, Regulation, Replication and repair.
NON-SPECIFIC(HISTONE)- Binding region not particular, so
bind to any of Grooves.
Ex- Histone, Ribosome, DNA Polymerase.
17. Helix-turn-helix: A DNA binding structure:-
Recognition and binding to DNA by done by the two α
helices,
One occupying the N-Terminal end of the motif, the other
at the C-Terminus.
In most cases, such as in the Cro repressor, the second
helix contributes most to DNA recognition, and hence it is
often called the “Recognition Helix".
It binds to the major groove of DNA through a series
of Hydrogen Bonds and various Van Der Waals
interactions with exposed Bases.
The other α helix stabilizes the interaction between
protein and DNA.
18.
19. Major vs minor grooves:-
N.B-
We need to develop drugs which attack any part or DNA
rather than the specific part of DNA because it will take
more time to cure.
So the drugs must bind to non specific site of DNA so it
binds to the minor grooves.
particulars Major groove Minor groove
Specific binding protein binds Doesn’t bind
Non-specific binding protein binds binds
groove binding drugs --- Binds