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Monday, December 27, 2010

PowerPoint Presentation On Wireless LAN Security

Wireless LAN Security


WLAN Security PPT


Friday, December 3, 2010

PPT On Packaging

Packaging Presentation


Packaging Presentation Transcript:
Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of design, evaluation, and production of packages.

The Oxford Dictionary: The business or process of packing goods or the presentation of a person or thing in an advantageous way. The American Heritage Dicitonary: The manner in which something, such as a proposal or product, or someone, such as a candidate or author, is presented to the public. Collins English Dictionary: The presentation of a person, product, television programme, etc., to the public in a way designed to build up a favorable image. Babylon’s Dictionary: The wrapping in which an item is presented for sale.

The first packages used the natural materials available at that time: Basket of reeds, wineskins, wooden boxes , pottery vases, ceramic amphorae, wooden barrels, woven bags, etc. Processed materials were used to form packages as they were developed: for example, early glass and bronze vessels. The study of old packages is an important aspect of archaeology.


The customer actually handles the product in its primary packaging. This level of packaging may be the one that the consumer sees. It is kept till it is opened or throughout the product’s life.

The Secondary packaging provides information to the consumer about the product. Additional layers of protection that are kept till the product is ready for use.

It Refers to the further packaging components necessary for :- Storage, Identification, Protection against damage and Durability.

Packaging is a very important marketing strategy to glamorize your product in order to attract the consumer’s attention. Sometimes packaging is so important that it cost more than the product itself in order to lure the consumers to buy it. Most consumers judge a product by its packaging before buying. So it is logical to say attractive packaging is crucial in order to get the first time buyers to buy your products. Packaging should definitely be included in the 4 major P’s of marketing (Product, Place, Promotion and Price).

Product Identification:- Packaging greatly helps in identification of products. Product Protection:- Packaging protects the contents of a product from spoilage, breakage, leakage, etc. Facilitating the use of product:- Packaging should be convenience to open, handle and use for the consumers. Product Promotion:- Packaging is also used for promotional and attracting the attention of the people while purchasing.

10. For more please refer our PPT. Thanks.

PPT On Love

What Is Love


Love Presentation Transcript:
1. Now Prepare Yourself for My Questions And Check What is It ??? LOVE or Anything Else !!!

2. Have You Try Any Time To Understand What is LOVE ???

3. Are your palms sweaty ? is your heart racing ? And is your voice caught within your chest ?

4. You can't keep your eyes or hands off of them, am I right??

5. Are you proud, and eager to show them off??

6. Do you want them because you know they're there??

7. Are you there because it's what everyone wants??

8. Are you there because they kissed you, or held your hand??

9. Do you stay for their confessions of love, because you don't want to hurt them??

10. For more please refer our PPT. Thanks.

PPT On Marketing

Online Marketing


International Marketing PPT


PPT On E-Marketing


Friday, November 19, 2010

PowerPoint Presentation On Computer Virus

PPT On Computer Virus




Tuesday, October 12, 2010

PowerPoint Presentation On Perception

PPT On Perception


Perception Presentation Transcript:
1. Perception
The process by which an individual selects, organizes, and interprets stimuli into a meaningful and coherent picture of the world.

2. Perception
You can see a white vase as figure against a black background, or two black faces in profile on a white background

3. Ambiguous figures
Can be seen in different ways to make different images. Best known ambiguous figure is “Old Woman/Young Woman,” by E. G. Boring

4. Müller-Lyer Illusion
The two lines above are the same length, but the diagonals extending outward from both ends of the lower line make it look longer than the upper line

5. What is Perception?
YOUR interpretation of “reality” after information/stimuli is …

6. Filtered out Selected Organized Defined ….using YOUR existing…

7. Elements of Perception Sensation The absolute threshold The differential threshold Subliminal perception

8. Sensory Receptors:
The human organs (eyes, ears, nose, mouth, skin) that receive sensory inputs. Absolute Threshold : The lowest level at which an individual can experience a sensation. Differential Threshold : The minimal difference that can be detected between two stimuli. Also known as the j.n.d. (just noticeable difference). Subliminal Perception: Perception of very weak or rapid stimuli received below the level of conscious awareness.

9. Price/Quality Relationship
The perception of price as an indicator of product quality (e.g., the higher the price, the higher the perceived quality of the product).

10. For more please refer our PPT. Thanks.

PowerPoint Presentation On Recession

PPT On Recession


Recession Presentation Transcript:
1. Before, understanding “Recession”, we need to understand the market economy;

2. C] What is Recession?
Recession is the economy shrinking for two consecutive quarters (=6 months) with a decrease in the GDP (=Gross Domestic Product) GDP = Value of all the reported goods and services produced by the people operating in the country

3. GDP is a good indicator of economy; Other indicators could be; -Unemployment Rate -Consumption Rate -Actual Personal Income -Etc.. If GDP is growing, then market is growing due to increased demand;

4. GDP is a good indicator of economy; Other indicators could be; -Unemployment Rate -Consumption Rate -Actual Personal Income -Etc.. If GDP is growing, then market is growing due to increased demand; Note: If the recession continues for next quarter, (>6 months) then we go through “DEPRESSION” Economy;

5. There is a joke that economists quote to explain the Difference between “Recession & Depression”

6. For more please refer our PPT. Thanks.

Wednesday, October 6, 2010

PowerPoint Presentations Of Electronics And Communication Engineering

Here we provide you PPTs of Electronics And Communication Engineering

PowerPoint Presentation On The Truth Of Life

The Truth Of Life


PowerPoint Presentation On Paradise On Earth

Paradise On Earth


Thursday, September 16, 2010

Friday, September 3, 2010

PowerPoint Presentation On Lord Krishna

Lord Krishna
On the occasion of janmastmi we have tried to show some moments of life of lord krishna.


Wednesday, September 1, 2010

PowerPoint Presentation On Gene Regulation

PPT On Molecular Mechanisms Of Gene Regulation


Gene Regulation Presentation Transcript:
1. Transcription Regulation:
Prokaryotes Transcription regulation is common mechanism in prokaryotes Negative Regulation = repressor binds to regulatory site to block transcription of active gene Positive Regulation = Activator binds to regulatory site to stimulate transcription; gene is off in absence of activator

2. Operon Model of Regulation
The operon consists of several structural genes required for lactose metabolism under the control of a single regulatory domain = coordinate regulation Repressor binding site = operator Site for transcriptional activation = promoter

3. Operon Model of Regulation
Inducible operon is activated by small molecule inducers; mode of regulation in degradative (catabolic) pathways Repressible operon is shut off by small molecule co-repressors; mode of regulation in biosynthetic (anabolic) pathways

4. Gene Regulation Mechanisms
Negative regulation: repressor protein blocks transcription: Inducible: inducer antagonizes repressor to allow transcription initiation Repressible: aporepessor combines with co-repressor to form functional repressor

5. Gene Regulation Mechanisms
Positive Regulation: transcription occurs only if promoter is activated by transcriptional activator Negative regulation is more common in prokaryotes Positive regulation is more common in eukaryotes Autoregulation: protein regulates its own transcription

 6. Lac Operon
Lactose degradation is regulated by the lactose (lac) operon The first regulatory mutations discovered affect lactose metabolism Structural proteins of the lac operon: B- galactosidase required for lactose metabolism and lactose permease required for lactose entry

7. Lac Operon
Lac operon gene expression can be inducible or constitutive The repressor is expressed constitutively (continuously) from the i gene and binds to the operator to block transcription The operon is inducible since lactose binds and inactivates the repressor to permit transcription initiation

8. Lac Operon
Lactose operator is essential site for repression Operator mutations are cis-dominant because only genes on the same genetic unit are affected Lactose promoter is essential site for transcription Lac operon contains linked structural genes and regulatory sites

9. Lac Operon
Lactose operon is also subject to positive regulation Positive regulation of the lac operon involves cAMP-CRP ( cyclic AMP receptor protein) which binds to the promoter to activate transcription by RNA polymerase cAMP-CRP complex regulates the activity of the lac operon

10. For more please refer our PPT. Thanks.

PowerPoint Presentation On Microbiological Study Of Milk

PPT On Microbiological Study Of Milk


PPT On Analysis Of  Dairy Milk


PowerPoint Presentation On Plant Tissue Culture

PPT On Plant Tissue Culture


PPT On Plant Tissue Culture Micropropagation 


PowerPoint Presentation On Gene Expression

PPT On Gene Expression


Gene Expression Presentation Transcript:
1. Gene is basic unit of heredity and is a segment for genomic information. It consist of both ‘coding’ and ‘non-coding’ sequences. These coding and non-coding sequences are copied in a process called Transcription producing RNA which directs the synthesis of proteins. Phenotype of an organism is an resultant of genes interacting with each other. Every cell has same set of genes so it is necessary to have a mechanism which allows desired gene to function at particular time. Expression of gene is not a single step process rather a vast system comprising a complex network. Activity of undesired genes has to be restricted which requires time and space.

2. Operon Negative control of lactose operon Positive control of lactose operon Mutation experiments by Jacob and Monod

3. F. Jacob and J. Monod in 1961 proposed a model to explain induction or repression of enzyme synthesis. This model is known as ‘Operon Model’ which assumes presence of coordinated control of protein synthesis and this unit is called ‘Operon’. Operon is a group of linked genes linked on chromosome under control of promoter and these linked genes gives rise to a single m-RNA. Operon consists of:- An operator gene which control activity Structural gene which participates in protein synthesis.

4. Histidine operon(his operon)- it has RNA element. Tryptophan operon(trp operon)- a repressible system which controls biosynthesis of tryptophan from precursor chorismic acid. Lactose operon(lac operon)- regulated by factors including presence of glucose and lactose.

5. An operon required for transport and metabolism of lactose in E.coli. E.coli cells when transferred to medium containing lactose instead of glucose, they stop growing for a certain period of time. They again starts growing as during lag phase cells turn on lac operon. Galactoside permease is the enzyme used for transport of lactose within cells. Lactose is made up of glucose and galactose linked by β-galactosidic bond. Three genes encoding above mentioned enzymes are: Lac Z- encodes for β galactosidase Lac Y- encodes for galactoside permease Lac A- encodes for galactoside transacetylase

 6. It is lac repressor coded by a gene called gene 1(lac 1). Repressor occupies operator and blocks access of RNA polymerase which in turn cannot transcribe lac Z, Y and A genes. Lac operon is repressed till glucose is available. In presence of lactose operon is turned on so that lactose can be metabolized. Repressor is an allosteric protein which changes its confirmation when it binds to small molecules. Inducer binds to repressor which is an alternate form of lactose called allolactose. Allolactose is glucose linked to galactose by β- 1,6 bond.

7. Allolactose acts as inducer by binding to repressor causing conformational shift. When repressor is , RNA polymerase is free to bind to lac promoter. It then transcribe three structural genes i.e. lac Z, lac A, lac Y.

8. E.coli cells metabolize glucose easily as compared to lactose Selection of glucose among other energy sources is influenced due to some breakdown products. It is thus called as Catabolite Repression. A nucleotide called cyclic AMP (cAMP) responds to glucose concentration. Its concentration responds inversely proportional to glucose concentration.

9. Positive controller is a complex comprising of two parts: cAMP Binding protein CAP (catabolite activator protein) Complex binds to promoter and turns it on by binding RNA polymerase Complex when binds, it causes promoter to bend and makes easier the DNA strands forming open promoter complex.

10. For more please refer our PPT. Thanks.

PowerPoint Presentation on History of Genetic Engineering

PPT On Genetic Engineering


History of Genetic Engineering Presentation Transcript:
1. Genetic engineering is normally taken to mean recombinant DNA technology -- the artificial addition, deletion or rearrangement of sequences of bases in DNA in order to alter the observable form and function of an organism. However, genetic engineering is sometimes referred to as biotechnology and biotechnologists have been quick to point out that mankind has been doing biotechnology ever since the first farmers some 10,000 years ago started to domesticate wild species by selecting seeds of wild plants for cultivation or selectively breeding wild animals. In this history, therefore, we include any artificial intervention in the reproductive process as well as some landmarks in the development of genetics which has made genetic engineering possible. This will include selection procedures old and new which could influence the genetic outcome of a reproductive event, gene therapy and diagnosis as well as cloning, vegetative reproduction and in vitro (test-tube) reproduction procedures.

2. circa 10,000 years ago The beginnings of agriculture: selection of wild grasses and subsequent breeding in cultivation to form the precursors of modern staples such as wheat, rice and maize. A considerable practical knowledge was developed by breeders over the centuries and selection procedures often achieved from a single wild species a huge difference in form and function: e.g. the Great Dane and Chihuahua dog varieties from the wolf. Furthermore, 'unnatural' hybrids -- i.e. creating breeds across species barriers -- were made in ancient times. For instance the mule, a cross between a jackass or male donkey and a mare has been used as a pack animal in Europe for at least 3,000 years.

3. 1627 Francis Bacon foretells genetic engineering and terminator technology.

4. 1859 Charles Darwin published the first edition of The Origin of the Species which amongst other things gives extensive information on the knowledge of breeding at that time. Download The Origin of the Species from either of the two sites below:

5. 1865 Gregor Mendel's publication of his discoveries with the breeding of peas which became the foundation of modern genetics. MendelWeb - Origins of classical genetics. 1866 Ernst Haeckel proposes that the cell nucleus is the bearer of an organism's heritable characteristics. 1869 Friedrich Miescher discovers nuclein -- a major component of which is DNA -- in the cell nucleus.

6. 1875 Oscar Hertwig using microscopy observes sea urchin sperm entering the egg and the two nuclei fusing. 1890 Birth of a rabbit from an embryo implanted in the uterus of a surrogate. 1900 Hugo de Vries, Carl Correns & Erich von Tschermak rediscover Mendel's principles.

7. 1902 Walter Sutton & Theodor Boveri propose the chromosome theory of inheritance. Archibald Garrod suggested from studies of alcaptonuria, a disease for which one symptom is the appearance of a black pigment in the urine, that a defective gene gave rise to a defective enzyme (a protein which is a biological catalyst in cell processes). 1910 T. H. Morgan demonstrated that the chromosomes are the concrete entities which carry the genes. (Also Clavin Bridges, 1916) 1913 A.H. Sturtevant constructed a genetic map.

8. 1927 H. J. Muller demonstrated that genetic mutation could be induced by X-rays.

9. 1931 Barbara McClintock and Harriet Creighton demonstrate direct physical recombination by examining maize chromosomes microscopically.

10. For more please refer our PPT. Thanks.

Friday, August 20, 2010

PowerPoint Presentation On Transcription

PPT On Prokaryotic Transcription


PPT On Transcription


PowerPoint Presentation On Mitochondria

PPT On Mitochondria


Mitochondria Presentation Transcript:
1. Introduction
Mitochondria were first seen by kollicker in 1850 in muscles and called them ‘sarcosomes’ Flemming (1882) described these organelles as ‘filia’ Altmann (1890) observed these structures and named them ‘bioblasts’. Benda (1898)stained these organelles with crystal violet and renamed them ‘mitochondria’ Michaelis (1900) used janus green B as a vital stain to observe mitochondria in living cells.

2. Morphology
The shape of mitochondria is highly variable ranges from short rod shape to elongate filamentous form . The size of mitochondria is variable ,they generally measures about 0.5 to 2um in diameter. Mitochondria have an average length of 3 to 4um. The number of mitochondria varies from one cell type to another. Mitochondria are not found in prokaryotes.

3. Ultra Structure
A mitochondria is enclosed by a double membrane envelope composed of lipid and protein. The two membranes are separated by a narrow fluid –filled space called the outer compartment. The outer membrane is smooth, it is more permeable to small molecules, contains some enzymes but is poorer in proteins. The inner membrane surrounds a central cavity or matrix (inner compartment) filled with a fluid. Folds of inner wall of mitochondria are called cristae.

4. Inner Membrane
Inner membrane is the site of the e- transport chain, across which the proton pump occurs and contains ATP synthase Inner membrane is highly folded – called cristae – increasing the surface area on which the above reactions can take place

5. Mitochondrial Inner Membrane
The inner mitochondrial membrane is compartmentalized into numerous cristae, which expand the surface area of the inner mitochondrial membrane, enhancing its ability to generate ATP. In typical liver mitochondria, for example, the surface area, including cristae, is about five times that of the outer membrane. Mitochondria of cells which have greater demand for ATP, such as muscle cells, contain more cristae than typical liver mitochondria.

6. Mitochondrial Outer Membrane
The outer mitochondrial membrane, which encloses the entire organelle, has a protein-to-phospholipid ratio similar to the eukaryotic plasma membrane (about 1:1 by weight). It contains numerous integral proteins called porins, which contain a relatively large internal channel (about 2-3 nm) that is permeable to all molecules of 5000 daltons or less. Larger molecules, for example most proteins, can only traverse the outer membrane by active transport.

7. Double membrane creates 2 spaces Matrix – large internal space Intermembrane space – between the membranes Outer membrane Inner membrane

8. Chemical Composition
 Mitochondria consists of protein-70 percent& lipids -25 -30percent. Mitochondria contain 0.5percent ofRNA &traces of DNA . Mitochondrial DNA comprises about 1 percent of total cell DNA Mitochondria contain enzymes for oxidation ,phosphorylation &electron transfer.

9. Generation of Energy
Millions of years ago there was no O2 available for oxidative phosphorylation to occur Organisms produced energy from fermentation, still see this today As O2 became available, a more efficient method of energy production developed Based on the transfer of e- along the membrane

10. For more please refer our PPT. Thanks.

Thursday, August 19, 2010

PowerPoint Presentation On Viruses

PPT On Viruses


PowerPoint Presentation On Genomic Library

PPT On Genomic Library


Genomic Library Presentation Transcript:
1. Genome - An Introduction
The total DNA present in the nucleus of each cell of an organism is its Genome. It comes from the terms Gene and Chromosome. It corresponds to all the organism’s bases: A,T,C,G. Our genome is a chain of 3.4 billion ‘pearls’. The genomes of two different people differ on an average by on ‘pearl’ in one thousand. Genes represent only about 5% of the total human genome. The role of all the non-coding sequences that make up the remaining 95% is today unknown, but researches have been able to assign functions to some of those sequences: some regulate DNA replication and transcription; others contribute to the chromosomal structuring. The Human Genome Project, launched in the early 1990s has succeeded in the completing the draft of DNA sequence(2003) of our entire genome. Genome is divided into chromosomes, chromosomes contain genes, and genes are made of DNA.

2. The word “genome” was coined in about 1930, however at that time the scientists had very little information about the real meaning of the word “Genome”. Each one of the earth’s species has its own distinctive genome. Genomes belong to species,& they also belong to individuals. Every Giraffe on the African Savanna has a unique genome, as does every elephant, acacia tree, & ostrich. Unless individuals are identical twins, their genomes are different from each other & every other person on earth-in fact it differs for every single individual who has ever lived. The entire world is full of Genomes. A genome is the information that affects every aspect of our behavior & physiology. Cooking dinner, digesting food talking, sleeping, reading – the genome plays a role in all these things. Thus studying the genome gives us insights into why some people live longer than others, why some die of heart disease and others of cancer, why some people have trouble keeping weight on while others have trouble keeping it off and so on.

3. Gene Library
A gene library is a collection of different DNA sequences from an organism each of which has been cloned into a vector for ease of purification, storage and analysis. There are essentially two types of gene library that can be made depending upon the source of the DNA used. If the DNA is genomic DNA, the library is called a genomic library. If the DNA is a copy of an mRNA population, that is cDNA, then the library is called a cDNA library. Size of the gene library A gene library must contain a certain number of recombinants for there to be a high probability of it containing any particular sequence. This value can be calculated if the genome size and the average size of the insert in the vector are known. Construction of libraries For making libraries, genomic DNA, usually prepared by protease digestion and phase extraction, is fragmented randomly by physical shearing or restriction enzyme digestion to give a size range appropriate for the selected vector. Often combinations of restriction enzymes are used to partially digest the DNA. Vectors Plasmids, Lambda phage, cosmid, BAC or YAC( yeast artificial chromosome) vectors can be used to construct genomic libraries, the choice depending on the genome size. The upper size limit of these vectors is about 10, 23, 45, 350, & 100 kb respectively. The genomic DNA fragments are ligated to the prepared vector molecules using T4 DNA ligase.

4. Genomic DNA Libraries
These libraries are made from genomic DNA (all the DNA found in the organism’s nuclei). Genomic DNA molecules are very large (each chromosome in the nucleus is one such DNA molecule), so they must be fragmented into small pieces to insert into vectors. This is done through digestion using one or more appropriate restriction endonucleases, mechanical shearing, or a combination of the two processes. The DNA is then ligated into the vector, which could be a plasmid, a cosmid (more often) or a viral chromosome. cDNA Libraries These libraries are made from cDNA (complimentary DNA), which are DNA copies of mRNA molecules. To make cDNA, mRNA is isolated from a tissue or whole organism, and DNA is copied from the mRNA template using an enzyme called reverse transcriptase. This enzyme works like a DNA polymerase, except that it uses RNA as a template instead of DNA. The resulting cDNA molecules are then engineered so that they have restriction enzyme recognition sites at each end of every molecule, which allows them to be digested and inserted into a vector.

5. Genomic Libraries
Definitions A library produced when the complete genome of a particular organism is cleaved into thousands of fragments, and all the fragments are cloned by insertion into a cloning vector. A form of gene library containing the complete DNA sequences present in the genome of a given organism. A collection of clones made from a set of randomly generated overlapping DNA fragments representing the entire genome of an organism. A set of thousands of DNA segments from a genome, each carried by a plasmid or a phage.

6. Construction of Genomic Libraries
The purpose of genomic library construction is to have an organism’s genome cloned as small fragments into separate vectors. Ideally the entire genome is represented: i.e., to say, the sum of the different fragments equals the entire genome. In this way specific groups of genes can be analyzed and isolated. The construction of a genomic library begins with cleaving the genome into small pieces by a restriction endonuclease. These genomic fragments are then either cloned into vectors & introduced into a microbe or packed into phage particles that are used to infect the host. In either case, many thousands of different clones- each with a different genomic DNA insert –are created. Therefore each clone will act as a “book” in this “library” of DNA fragments. If the genomic library has been inserted into a microbe that expresses the foreign gene, it may be possible to assay each clone for a specific protein or phenotype.

7. For more please refer our PPT. Thanks.

PowerPoint Presentation On RNA Polymerase Enzyme

PPT On RNA Polymerase Enzyme


RNA Polymerase Enzyme Presentation Transcript:
1. 1. The DNA replicates its information in a process that involves many enzymes: replication. 2. The DNA codes for the production of messenger RNA (mRNA) during transcription. 3. In eucaryotic cells, the mRNA is processed (essentially by splicing) and migrates from the nucleus to the cytoplasm. 4. Messenger RNA carries coded information to ribosomes. The ribosomes "read" this information and use it for protein synthesis. This process is called translation. Proteins do not code for the production of protein, RNA or DNA. They are involved in almost all biological activities, structural or enzymatic.

2. Transcription
Transcription is the process by which a single stranded RNA is formed from a single strand of DNA. The process involves : Uncoiling of the 2 strands of DNA in a specific region. It exposes the bases of the DNA strands. One strand of DNA remains dormant & the other one acts as the template for the formation of the new RNA strand. The building blocks the free nucleotides align themselves & form the complementary RNA according to the base pairing rule. The reaction is catalyzed by the enzyme RNA Polymerase. RNA polymerase catalyzes the formation of phosphodiesterase bonds between nucleotides (using tri-phosphate nucleotides). RNA polymerase moves stepwise along the DNA extending the RNA chain as it goes. As RNA polymerase moves it unwinds the next part of the helix, the helix behind closes & the mRNA is displaced

3. RNA polymerase
(RNAP or RNApol) is an enzyme that makes a RNA copy of a DNA or RNA template. In cells, RNAP is needed for constructing RNA chains from DNA genes, a process called transcription. RNA polymerase enzymes are essential to life and are found in all organisms and many viruses. In chemical terms, RNAP is a nucleotidyl transferase that polymerizes ribonucleotides at the 3' end of an RNA transcript.

4. History RNA Polymerase
or RNAP was discovered independently by Sam Weiss & Jerard Hurwitz in 1960. In 2006, the Nobel Prize in Chemistry was awarded to Roger Kornberg for creating detailed molecular images of RNA polymerase during various stages of transcription.

5. Structure Of RNA Polymerase
RNA polymerase in Prokaryotes (Bacteria) : In bacteria, the same enzyme catalyzes the synthesis of mRNA RNAP is a relatively large molecule. The core enzyme has 5 subunits (~400 kDa):α2: the two α subunits assemble the enzyme and recognize regulatory factors. Each subunit has two domains: αCTD (C-Terminal domain) binds the UP element of the extended promoter, and αNTD (N-terminal domain) binds the rest of the polymerase. β: this has the polymerase activity (catalyzes the synthesis of RNA) which includes chain initiation and elongation. β': binds to DNA (nonspecifically). ω: restores denatured RNA polymerase to its functional form in vitro.

6. For more please refer our PPT. Thanks.

PowerPoint Presentation On Quorum Sensing

PPT On Quorum Sensing


Quorum Sensing Presentation Transcript:
1. Introduction To Quorum Sensing
- Cell to cell communication among procaryotes occurs by the exchange of small molecule often termed signal or signaling molecule. The exchanging of signaling molecule is essential in the co-ordination of gene expression of microbial population Quorum sensing is a type of decision-making process used by decentralized groups to coordinate behavior. Many species of bacteria use quorum sensing to coordinate their gene expression according to the local density of their population.

2. Quorum sensing was firstly discovered in the marine bioluminescent bacteria Vibrio fischeri , which produce light only if cells are at high density. It has been discovered that intercellular communication play an essential role in the regulation of gene whose products are needed for establishment of virulence, symbiosis , Biofilm production, plasmid transfer &morphological differentiation in a wide range of microbes.

3. Quorum Sensing
Fuqua et al. (1994) introduced the term quorum sensing to describe cell-cell signaling in bacteria Early 1990’s – homologs of LuxI were discovered in different bacterial species V. fischeri LuxI-LuxR signaling system becomes the paradigm for bacterial cell-cell communication

4. Methods & Mechanism
 For a molecule to classed as a quorum sensing signal there are number of important criteria that need to be met → The production of the quorum sensing signal should takes place during specific stage of growth or in response to particular environment changes. The quorum sensing should accumulate in extra cellular environment & be recognized by a specific bacterial receptor.

5. The accumulation of a critical threshold concentration of the quorum sensing signal should be stimulate a response. The cellular response should extend beyond the physiological changes required to metabolized.

For quorum sensing bacteria produce certain signaling compounds called as Auto inducer. Eg. N- acyl homoserin lactos (AHL) They have a receptor that detect AHL. AHL binds with the receptor it activate transcription of certain genes & also those for inducer synthesis.

7. Mechanism
When only few bacterias are present then concentration of AHL decreases or if number of bacteria are present then concentration of AHL increases. When many kinds of bacterias are present concentration of inducer AHL posses the threshold. It causes a +ve feed back loop & receptor become active.

Species of gram –ve bacteria signaling transfer a series of AHL & it’s concentration exceed a threshold i.e. the cell population over a certain no., the promoter plux transcription is activates.

 9. Quorum Sensing in Gram-Positive Bacteria Gram-positive bacteria utilizes modified oligopeptides as signaling molecules – secreted via an ATP-binding cassette (ABC) transporter complex Detectors for these signals are two-component signal transduction systems

10. For more please refer our PPT. Thanks.

PowerPoint Presentation On Proteins

PPT On Proteins


Proteins Presentation Transcript:
1. Proteins- Introduction
The word protein comes from the Greek ("prota"), meaning "of primary importance" and these molecules were first described and named by the Swedish chemist Jöns Jakob Berzelius in 1838. However, proteins' central role in living organisms was not fully appreciated until 1926, when James B. Sumner showed that the enzyme urease was a protein. The first protein to be sequenced was insulin, by Frederick Sanger, who won the Nobel Prize for this achievement in 1958. The first protein structures to be solved included hemoglobin and myoglobin, by Max Perutz and Sir John Cowdery Kendrew, respectively, in 1958. Both proteins' three-dimensional structures were first determined by x-ray diffraction analysis; the structures of myoglobin and hemoglobin won the 1962 Nobel Prize in Chemistry for their discoverers.

2. Proteins
 Proteins are large complex molecules composed of long chains of amino acids called polypeptides. Proteins are polymers and amino acids are their monomers. C,H,O,S are the elements found in the proteins.

3. Amino Acids
There are 20 amino acids that are common to all life forms. The number and arrangement of these 20 amino acids yields infinite variety of proteins

4. Amino Acids are classified by their “Alkyl” “R” Group: Acidic Amino acid Basic Amino Acids Polar Amino Acids Non-Polar Amino Acids

5. Peptide Bonds Joins two amino acids into a dipeptide Bond forms between carboxyl group of one amino acid and amine group of the second amino acid Peptide bond forms by a condensation reaction losing a molecule of water with each bond

6. Primary Protein Structure

7. Helix
Most abundant 2' structure in proteins Average length = 10 aa's (~10 Angstroms) Length varies from 5-40 aa's Alignment of H-bonds creates dipole moment (positive charge at NH end) Often at surface of core, with hydrophobic residues on inner-facing side, hydrophilic on other side

8. Types of helices
"Standard" helix: 3.6 residues per turn H-bonds between C=0 of residue n and NH of residue n + 4 Helix ends are polar; almost always on surface of protein

9. Certain amino acids are "preferred" & others are rare in helices Ala, Glu, Leu, Met = good helix formers Pro, Gly Tyr, Ser = very poor Amino acid composition & distribution varies, depending on location of helix in 3-D structure

10. For more please refer our PPT. Thanks.

PowerPoint Presentation On Biosensor

PPT On Biosensor


Biosensor Presentation Transcript:
1. Introduction /Definition
A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. OR A biosensor is an analytical devices which employs a biological material to specifically interact with an analyte.

2. Biosensor consists of 3 parts:-
Sensitive biological element & analyte. Transducer or the detector element. Electronic or signal processor / Amplifier.

3. Components of biosensor:-
Analyte. Biological material. Transducer. Amplifier. LED screen/ PC.

4. Sensitive biological element:-
Biological material a biologically derived material or can be created by biological engineering. Biological material is like tissue, cell receptor, enzymes, antibodies, nucleic acid etc. The biological component of biosensor performs the following two key function - It specifically recognizes the analyte . Interacts with it in such a manner , which produces some physical change detectable by the transducer.

5. Transducer or the detector element:-
The biological component interacts specifically to the analyte, which produced a physical change close to the transducer surface. Transducer detects & measures this change and converts it into an electrical signal. Transducer work in a physicochemical way, optical way, piezoelectric way, electrochemical way etc.

6. Analyte:-
An analyte is a compound whose concentration is to be determined by the biosensor. The nature of interaction between the analyte and the biological material used, the biosensor may be of two types – The analyte may be converted into a new chemical molecule , such biosensor are called CATALYTIC BIOSENSOR. The analyte may simply bind to the biological material, these biosensor are known as AFFINITY BIOSENSOR.

7. Immobilization of Biological element:-
A biosensor makes use of a biological molecule (an enzyme ) that is immobilized to detect an analyte. The immobilization permits repeated use of the costly biological molecule.

8. Working principle of biosensor:-
The biosensor convert a chemical information flow, into an electrical information flow, which involves the following steps - 1.The analyte diffuses from the solution to the surface of the biosensor. 2.The analyte react specifically & efficiently with the biological component of the biosensor. 3.This reaction change the physicochemical properties of the transducer surface. 4.This leads to a change in the optical/electronic properties of the transducer surface. 5.The change in optical/electronic properties is measured/ converted into electrical signal, which is amplified, processed and displayed.

9. Features of biosensor:-
A successful biosensor must have at least some of the following features – Highly specific for analyte. Independent of factors like stirring, pH, temp., etc. Linear response, tiny and biocompatible. Cheap, easy to use & durable/repeated use. Cost is lower than that of conventional tests. Require small sample volume. Rapid, accurate, stable, & sterilizable.

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PowerPoint Presentation On DNA

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PowerPoint Presentation On Nitrogen Metabolism

PPT On Nitrogen Metabolism


Nitrogen Metabolism Presentation Transcript:
Nitrogen Fixation can be defined as the conversion of molecular nitrogen into fixed form of nitrogen to make it available for absorption by plants. It is the third most important process after respiration and photosynthesis. It is essential for all living organisms.

Conversion of elemental nitrogen or gaseous nitrogen into nitrogenous compounds or salts by certain microorganisms like bacteria ,blue green algae, fungi etc. is called biological nitrogen fixation. It is carried by two types of micro- organisms. Eg Symbiotic and non-symbiotic.

The Fixation of free nitrogen of the soil by all those micro-organisms living freely or outside the cell is called as non-symbiotic biological N2 fixation.

The Fixation of free nitrogen of the soil by microorganisms living symbiotically inside the plant, is called as symbiotic biological N2-fixation. The term “symbiosis” is coined by De bary in 1879.

Nitrogen Fixation Through Nodule Formation in Leguminous plants. N2 Fixation through Nodule formation in Non-leguminous Plants. N2-Fixation through Non-Nodulation.

In addition to legumes, there are many plants specially trees and shrubs belonging to families other than Leguminosae which produce root-nodules. Eg- Casuarina- Frankia Alnus- Frankia Myrica- Frankia Parasponia- Rhizobium

7. N2 Fixation through Non-nodulation It includes those plants where root nodules are not formed but symbiotic N2-fixation takes place. Examples- Lichens - associated with fungi and algae Azolla- Anabaena azollae. Cycas –Anabaena or Nostoc Gunnera macrophylla- Nostoc

8. Associative Symbiotic N2-Fixation
When the bacteria live in close association with the roots of cereals and grasses and fix nitrogen than the association is of loose mutualism type and is called associative symbiosis whereas this nitrogen Fixation is called associative symbiotic nitrogen fixation. Examples- Azotobactor paspali – Associated with Paspalum notatum Azospirillum brasilense- Cereal roots Beijerinckia- Sugarcane roots

The red pigment of the nodules is called leg-hemoglobin and appears to be a product of the Rhizoboium-legume complex. The pigment is not present in either organism grown alone. It is a reddish pigment found in the cytoplasm of host cells. It is an oxygen carrier & an efficient O2 scavenger

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PowerPoint Presentation On Mutations

PPT On Mutations


Mutations Presentation Transcript:
Mutation are heritable changes in the genetic material. They result from small changes in the genetic material (single gene mutations), rearrangements in chromosome structure (chromosome mutations), or changes in chromosome number( genome mutations).

Spontaneous mutation Induced mutations

Spontaneous mutations can arise from transition, transversion and frameshifts), from dNA lesions (replication errors (apurinic sites, apyrimidinic sites, oxidation ), and from insertions.

The tautomeric shifts changes the hydrogen bonding characteristics of the bases allowing purine for purine, pyrimidine for pyrimidine substitution that eventually leads to a stable alteration of nucleotide sequences. Such alterations are known as transition mutation.

In transversion mutations, a purine is substituted for a pyrimidine, or a pyrimidine for purine. These mutations are rare due to steric problems of pairing purine with purine and pyrimidine with pyrimidine.

Induced mutation are caused by mutagens. Mutations may result from the incorporation of base analogs, specific misparing due to alteration of a base, the presence of intercalating agents, and a by pass of replication because of severe damage.

Base analogs are structurally similar to normal nitrogenous bases and can be incorporated into the growing polynucleotide chain during replication. Once in place, these compounds typically exhibit base pairing properties different from the bases they replace and eventually causes stable mutations.

Specific mispairing is caused when a mutagen changes a base structure and therefore alters its base pairing characteristics. Some mutagens in this category are fairly selective; they preferentially react with some bases and produce a specific kind of DNA damage.

Intercalating agents distort DNA to induce single nucleotide pair insertion and deletion. These mutagens are planar and insert themselves (intercalate) between the stacked bases of the helix.

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PowerPoint Presentation On The Cell Wall

PPT On The Cell Wall


The Cell Wall Presentation Transcript:
The plant cell wall is a remarkable structure. It provides the most significant difference between plant cells and other eukaryotic cells. The cell wall is rigid (up to many micrometers in thickness) and gives plant cells a very defined shape. While most cells have a outer membrane, none is comparable in strength to the plant cell wall. The cell wall is the reason for the difference between plant and animal cell functions. Because the plant has evolved this rigid structure.

2. On the basis of chemical composition of cell wall there are three types of cell wall: 1) Green Plant Cell Wall : which is made up of Cellulose. 2) Cell Wall of Fungi: made up of Chitin. 3) Bacteria Cell Wall: made up of Mucopeptide and Muramic Acid. The cell wall is composed of Cellulose, fibres, polysaccharides and proteins i.e Living Protoplast. It consist of the following: Middle lamella Primary Cell Wall Secondary Cell Wall Tertiary Cell Wall

It is present between two adjacent cells. It is situated outside primary cell wall and is made up of calcium and magnesium pectate. It acts as cement which holds the adjacent cells together.
2. PRIMARY CELL WALL It is present beneath Middle lamella. It is made up of Cellulose, Hemi-cellulose, pectic substances, lipids, proteins, minerals, elements and water.

It is present beneath Primary Cell wall. It is made up of Cellulose, Hemi-cellulose and polysaccharides. Secondary Cell wall is deposited Lignin.
4. TERTIARY CELL WALL Tertiary Cell wall is deposited in few cells. It is considered to be dry residue of protoplast. Besides Cellulose and Hemi-cellulose, Xylan is also present.

5. On the whole, each cell's cell wall interacts with its neighbours to form a tightly bound plant structure. Despite the rigidity of the cell wall, chemical signals and cellular excretions are allowed to pass between cells.

6. The primary wall of cells are capable of expansion. The middle lamella is formed during cell division and grows coordinately during cell expansion. Contact between certain cells is maintained by the middle lamella , and the cell corners are often filled with pectin rich polysaccharides. In older cells the material in the cell corners is sometimes degraded and an air space formes.

7. Plant cell walls
Are made of cellulose fibers embedded in other polysaccharides and protein May have multiple layers

8. Cell Wall components
Cellulose Other carbohydrates Lignin (other polyphenolics) Proteins

9. Carbohydrates
Classified by solubilities Pectins – complex carbohydrates extracted in water using Calcium chelators Polyuronic acids Arabinans Glactans Hemicelluloses – soluble in 4M KOH Xylans - common Mannans – abundant in conifers Arabinoglactans Microfibrillar components Cellulose Beta 1,4 mannans - algae Beta 1,3 xylans - algae

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PowerPoint Presentation On Carbohydrates

PPT On Carbohydrates


Carbohydrates Presentation Transcript:
The name Carbohydrates indicates that they are hydrates of Carbon, and contain carbon, hydrogen and oxygen. Most of them contain hydrogen and oxygen in the ratio of 2:1. For that reason, the general empirical formula of carbohydrates is given as [C(H2O)]n e.g,glucose is (C6H12O6) carbohydrates may be defined as Polyhydroxy aldehyde or Ketone or substances that yield these on hydrolysis.e.g.glucose is a polyhydroxy aldehyde and fructose is a polyhydroxy ketone. The names of carbohydrates often end in the suffix-ose.

The carbohydrates often termed as Sugars,are the “staff of life” for most organisms. Carbohydrates are also known as Saccharides(Sakcharon=sugar or sweetness). They are widely distributed molecules in both plant and animal tissues. They are indispensable for living organisms,serving as skeletal structures in plants and also in insects and crustaceans. They also occur as food reserves in the storage organs of plants and in liver and muscles of animals. In addition,they are an important source of energy required for the various metabolic activities of the living organisms;the energy being derived as a result of their oxidation.

The naturally occurring carbohydrates may be classified into three main groups,particularly on the basis of their behaviour towards hydrolysis. Monosaccharides are classified according to three different characteristics: the placement of its carbonyl group,the number of carbon atoms it contains, and its chiral handedness. If the carbonyl group is an aldehyde,the monosaccharide is an aldose; if the carbonyl group is ketone;the monosaccharide is a ketose.Monosaccharide with three carbon atoms are called trioses,those with four are called tetroses,five are called pentoses,six are called hexoses.

4. MONOSACCHARIDES(GK:Mono=one;Sakcharon=sugar)
 They are the simplest sugars and cannot be hydrolysed into simpler compounds. Their general formula is CnH2nOn,where n varies from 3to7.The most important are the pentoses and hexoses.

5. OLIGOSACCHARIDES(GK:oligo=few;Sakcharon=sugar)
On hydrolysis they generally yield 2 to 9 molecules of monosaccharides which are sugars and include di-, tri-tetrasaccharides etc. The monosaccharides are joined together by glycosidic bonds. glycosidic linkage formed via a dehydration reaction, resulting in the loss of a hydrogen atom from one monosaccharide and a hydroxyl group from the other. The most abundant are the disaccharides, which consist of two monosaccharide units.

Polysaccharides are the carbohydrates which yield a large number of monosaccharides on hydrolysis. They contain greater than ten monosaccharide units.

Monosaccharides possess some characteristic properties due to the presence of some specific groups,namely aldehydic,alcoholic,alchol-aldehydic,and α-glycolic. Oxidation with acids: With mild oxidants(like HOBr):-Only the aldehyde group is oxidized to produce monocarbolic acids.Ketoses,however don’t respond to this reaction.Hence reaction is used to distinguish aldoses from ketoses.

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PowerPoint Presentation On Apoptosis

PPT On Apoptosis


Apoptosis Presentation Transcript:
Apoptosis means “programed cell death”. It’s role in cell population control during growth and development suggests that there are inherent cellular mechanisms that lead the cell to destruction. It is a form of cell death which is different from any other form of cell death-necrosis.

Cell death by injury -Mechanical damage -Exposure to toxic chemicals Cell death by suicide -Internal signals -External signals

3. Conted…..
Apoptosis or programmed cell death, is carefully coordinated collapse of cell, protein degradation , DNA fragmentation followed by rapid engulfment of corpses by neighbouring cells. (Tommi, 2002) Essential part of life for every multicellular organism from worms to humans. (Faddy et al.,1992) Apoptosis plays a major role from embryonic development to senescence.

4. History of cell death / apoptosis
research 1800s Numerous observation of cell death 1908 Mechnikov wins Nobel prize (phagocytosis) 1930-40 Studies of metamorphosis 1948-49 Cell death in chick limb & exploration of NGF 1955 Beginning of studies of lysomes 1964-66 Necrosis & PCD described 1971 Term apoptosis coined 1977 Cell death genes in C. elegans 1980-82 DNA ladder observed & ced-3 identified 1989-91 Apoptosis genes identified, including bcl-2, fas/apo1 & p53, ced-3 sequenced (Richerd, 2001)

5. Why should a cell commit suicide?
Apoptosis is needed for proper development Examples: The resorption of the tadpole tail The formation of the fingers and toes of the fetus The sloughing off of the inner lining of the uterus The formation of the proper connections between neurons in the brain Apoptosis is needed to destroy cells Examples: Cells infected with viruses Cells of the immune system Cells with DNA damage Cancer cells

6. What makes a cell decide to commit suicide?
Withdrawal of positive signals examples : growth factors for neurons Interleukin-2 (IL-2) Receipt of negative signals examples : increased levels of oxidants within the cell damage to DNA by oxidants death activators : Tumor necrosis factor alpha (TNF-) Lymphotoxin (TNF-β) Fas ligand (FasL)

7. Necrosis vs. Apoptosis
Cellular swelling Membranes are broken ATP is depleted Cell lyses, eliciting an inflammatory reaction DNA fragmentation is random, or smeared In vivo, whole areas of the tissue are affected Cellular condensation Membranes remain intact Requires ATP Cell is phagocytosed, no tissue reaction Ladder-like DNA fragmentation In vivo, individual cells appear affected

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PowerPoint Presentation On Genetic Recombination

PPT On Genetic Recombination


Genetic Recombination Presentation Transcript:
1. Genetic Recombination
INTRODUCTION : Genetic recombination is the process by which a strand of DNA is broken and then joined to the end of a different DNA molecule. In eukaryotes recombination commonly occurs during meiosis as chromosomal crossover between paired chromosomes. This process leads to offspring having different combinations of genes from their parents and can produce new chimeric alleles. In evolutionary biology this shuffling of genes is thought to have many advantages

2. A recombination pathway in DNA is any way by which a broken DNA molecule is reconnected to form a whole DNA strand. In molecular biology "recombination" can also refer to artificial and deliberate recombination of disparate pieces of DNA, often from different organisms, creating what is called recombinant DNA.

When crossing over occurs between sister chromatids its called sister chromatid exchange . sister chromatid are genetically identical to each other, wit,sce does not produce a recombination of alleles. Therefore it is not considered a form of recombination .By comparison , it is also common for homologous chromosomes to cross over.

4. Perry and wolf produced harlequin chromosomes to reveal recombination between sister chromatid. In 1970s, The Russian cytogeneticist A.F ZAKHROV AND COLLEAGUES spent much more effort developing methods that inproved our ability to identify chromoes.They mode the intresting observation that chromes labled with the nucleotide analogue 5- bromo deoxyurinide become more fluorescent when stained with giemsa and then visualized microscopically.

5. Perry and wolff, grew eukaryotic cells in a laboratory and exposed them to BrdU for two rounds of DNA replication . after the second round of DNA replication , one of the sister chromatid contained one normal strand and one BrdU labled strand. The other sister chronatid have two BrdU –labled strands . when treated with two dyes , Hoechst33258 and giemsa , the sister chromatid containing two strands with BrdU stains very weakly and appears light, whereas the sister chromatid with only one strand containing BrdU stains much more strongly and appears very dark. In this way , the two sister chromatid can be distinguished microscopically . chromosomes stained in this way have been regerred to as harlequin chromosomes , because they are reminiscent of a harlequin characters costumes with its variegated pattern of light and dark patches.

Refers to recombination between the paired chromosomes inherited from each of one's parents, generally occurring during meiosis. During prophase I the four available chromatids are in tight formation with one another. While in this formation, homologous sites on two chromatids can mesh with one another, and may exchange genetic information. Because recombination can occur with small probability at any location along chromosome, the frequency of recombination between two locations depends on their distance. Chromosomes are expected to cross over at many points along their length; independently.

7. The Holliday Model of Genetic Recombination
This model of recombination was first proposed by Robin Holliday in 1964 and re-established by David Dressler and Huntington Potter in 1976 who demonstrated that the proposed physical intermediates existed. Alignment two homologous DNA molecules. Nick the DNA at the same place on the two molecules. This must happen in strands with the same polarity.

8. Exchange strands and ligate.
The intermediate that is formed is called a Holliday intermediate or Holliday structure. The shape of this intermediate in vivo is similar to that of the greek letter chi, hence this is also called a chi form.

9. Resolution of the structure.
There are two ways in which this can happen: If the same strands are cleaved a second time then the original two DNA molecules are generated: If the other strands are cleaved, then recombinant molecules are generated:

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Wednesday, August 18, 2010

Best PPT Provider Of The Week

Hello friends as you know, some day before we announced a contest which name was Best PPT Provider so now we are going to announce the result of the contest.

The winner of the contest is Mr. Manish Ojha who is now doing MBA from JECRC School Of Management , JAIPUR (RAJASTHAN). in Finance .His PPT Is  Sales and Distribution Management

NAME:          Manish Ojha
EDU.:             Persuring MBA.
Phone No. :     +91-9928928607
Email Id :

If you want your pic here just send us some good PPTs which are made by you, if your PPT is selected in our contest we promote you just like this for one send your PPTs as much as possible  to us by just going to our Submit PPT Section.

PowerPoint Presentation On Microscopic Techniques

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