DNA
Deoxyribonucleic acid and ribonucleic acid are two chemical substances involved in transmitting genetic information from parent to offspring. It was known early into the 20th century that chromosomes, the genetic material of cells, contained
DNA. In 1944, Oswald T. Avery, Colin M. MacLeod, and Maclyn McCarty concluded that DNA was the basic genetic component of chromosomes. Later, RNA would be proven to regulate protein synthesis. (Miller, 139)
DNA is the genetic material found in most viruses and in all cellular organisms.
Some viruses do not have DNA, but contain RNA instead. Depending on the organism, most DNA is found within a single chromosome like bacteria, or in several chromosomes like most other living things. (Heath, 110) DNA can also be found outside of chromosomes. It can be found in cell organelles such as plasmids in bacteria, also in chloroplasts in plants, and mitochondria in plants and animals.
All DNA molecules contain a set of linked units called nucleotides. Each nucleotide is composed of three things. The first is a sugar called deoxyribose.
Attached to one end of the sugar is a phosphate group, and at the other is one of several nitrogenous bases. DNA contains four nitrogenous bases. The first two, adenine and guanine, are double-ringed purine compounds. The others, cytosine and thymine, are single-ringed pyrimidine compounds. (Miller, 141) Four types of
DNA nucleotides can be formed, depending on which nitrogenous base is involved.
The phosphate group of each nucleotide bonds with a carbon from the deoxyribose.
This forms what is called a polynucleotide chain. James D. Watson and Francis
Crick proved that most DNA consists of two polynucleotide chains that are twisted together into a coil, forming a double helix. Watson and Crick also discovered that in a double helix, the pairing between bases of the two chains is highly specific. Adenine is always linked to thymine by two hydrogen bonds, and guanine is always linked to cytosine by three hydrogen bonds. This is known as base pairing. (Miller, 143)
The DNA of an organism provides two main functions. The first function is to provide for protein synthesis, allowing growth and development of the organism.
The second function is to give all of it’s descendants it’s own protein- synthesizing information by replicating itself and providing each offspring with a copy. The informat...
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... were slid along the mRNA until their nucleotides matched.
Conclusions:
The most surprising discovery made was finding out that there are only four main bases needed in a DNA and RNA molecule. Also, each of these bases will only bond with one other base. It is important to realize how DNA greatly affects a cell’s functions, in growth, movement, protein building, and many other duties. DNA is not nearly complex in structure as I had thought either. Containing only it’s three main parts of a sugar, phosphate, and of course it’s base. From these studies it is easy to see how DNA and RNA greatly affect the life and functions of an organism.
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Hole, John W., Jr. Essentials. Dubuque, Iowa: Wm. C. Brown Company Publishers,
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Mader, Sylvia S. Inquiry Into Life. New York: Wm. C. Brown Company Publishers,
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Miller, Kenneth R. Biology. New Jersey: Prentice Hall, 1993.
Welch, Claude A. Biological Science. Boston: Houghton Mifflin Company, 1968.
in the sample in to many identical samples. The DNA retrieved from the reaction can then be
. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a large number of individuals released or convicted of crimes based on DNA left at the crime sceneDNA is the abbreviation for deoxyribonucleic acid. DNA is the genetic material found in cells of all living organisms. Human beings contain approximately one trillion cells (Aronson 9). DNA is a long strand in the shape of a double helix made up of small building blocks (Riley). There are four types of building
In order to do this a polymer of DNA “unzips” into its two strands, a coding strand (left strand) and a template strand (right strand). Nucleotides of a molecule known as mRNA (messenger RNA) then temporarily bonds to the template strand and join together in the same way as nucleotides of DNA. Messenger RNA has a similar structure to that of DNA only it is single stranded. Like DNA, mRNA is made up of nucleotides again consisting of a phosphate, a sugar, and an organic nitrogenous base. However, unlike in DNA, the sugar in a nucleotide of mRNA is different (Ribose) and the nitrogenous base Thymine is replaced by a new base found in RNA known as Uracil (U)3b and like Thymine can only bond to its complimentary base Adenine. As a result of how it bonds to the DNA’s template strand, the mRNA strand formed is almost identical to the coding strand of DNA apart from these
DNA is the blueprint of life from its creation to its development and until its death. The discovery of the structure of DNA not only revolutionized science and medicine, but it also affected many other facets of existence: evolutionary, industrial, legal, and criminal justice. Its incarnation has benefitted American families and industries and spurred scientific innovation throughout the country. Aptly stated by Francis Crick, “your joys and your sorrows, your memories and your ambitions, your sense of identity and freewill, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. As Lewis Carroll’s Alice might have phrased it: ‘you’re nothing but a pack of neurons.’ [Watson and my] discovery illustrates how that is possible.”
Everyone is familiar with the blue print, or book, of life. Deoxyribonucleic Acid, or DNA, for short. After all, every single cell of our trillion possesses a double-membraned blob (nucleus) just to house it. As with anyone who ever studied genetics, pilgrims to the Delphic oracle in ancient Greece always discovered something profound about them when they inquired of it-but rarely that which they assumed to have learned in the first place. The Greek king Croesus once asked the oracle if he should commence a war with a neighboring kingdom only to be told “You will destroy a great empire”. He did only his own. Likewise, DNA speaks in code with the occasional satirical message. Unlike Delphi, our oracle still speaks, and louder than ever. From
The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides. Each nucleotide has three components; a phosphate group, a sugar and a base that contains nitrogen within its structure. The sugar moiety in DNA oligonucleotides is always dexoyribose, and there are four alternative bases: adenine (A), thymine (T), guanine (G), and cytosine (C). The phosphate groups and the deoxyribose sugars form the backbone of each DNA stand. The bases are joined to the deoxyribose sugar and stick out to the side. Both oligomers, DNA and RNA, consist of 5’->3’ phosphodiester-linked nucleotide units that are composed of a 2’-deoxy-D-ribose (DNA) or D-ribose (RNA) in their furanose forms and a heteroaromatic nucleobase (A, T, G, and C; A, U, G, C), and the resulting oligonucleotide chain is composed of a polar, negatively charged sugar-phosphate backbone and an array of hydrophobic nucleobases. The amphiphilic nature of these polymers dictates the assembly and maintenance of secondary and tertiary structures the oligonucleotides can form. In the DNA duplex structure, genetic information is stored as a linear nucleotide code. This code can be accessed and replicated. RNA, or ribonucleic acid, is another structurally related essential biopolymer. RNA differs from DNA in having the sugar ribose in place of the deoxyribos...
Deoxyribo Nucleic Acid (DNA) is a chromosome found in the nucleus of a cell, which is a double-stranded helix (similar to a twisted ladder). DNA is made up of four bases called adenine (A), thymine (T), guanine (G), and cytosine (C), that is always based in pairs of A with T and G with C. The four bases of A, C, G, and T were discovered by Phoebus Levene in 1929, which linked it to the string of nucleotide units through phosphate-sugar-base (groups). As mention in Ananya Mandal research paper, Levene thought the chain connection with the bases is repeated in a fix order that make up the DNA molecu...
DNA is continuously evolving as it has developed various aspects of illicit cases, as well as playing vital roles in all cellular systems. The discovery of DNA has impacted and will trigger the fuel of new findings later in the future. DNA does not only significantly affect a cell’s function, but it aids the species to develop and reproduce, despite the altering conditions.
DNA in forensic science has been around for a long time. DNA has had help in solving almost every crime committed. There have been a lot of crimes where people are raped or murdered and the person who did it runs free. Scientists can collect the littlest item they see at the scene, such as a cigarette butt or coffee cup and check it for DNA. People have spent years in jail for a crime they didn’t commit till DNA testing came into effect. People are getting out of jail after 20 years for a crime they didn’t commit, cause of the DNA testing. DNA has helped medical researchers develop vaccines for disease causing microbe. DNA has become a standard tool of forensics in many murders and rapes.
This paper explores deoxyribonucleic acid (DNA) collection and its relationship to solving crimes. The collection of DNA is one of the most important steps in identifying a suspect in a crime. DNA evidence can either convict or exonerate an individual of a crime. Furthermore, the accuracy of forensic identification of evidence has the possibility of leaving biased effects on a juror (Carrell, Krauss, Liberman, Miethe, 2008). This paper examines Carrells et al’s research along with three other research articles to review how DNA is collected, the effects that is has on a juror and the pros and cons of DNA collection in the Forensic Science and Criminal Justice community.
Before the 1980s, courts relied on testimony and eyewitness accounts as a main source of evidence. Notoriously unreliable, these techniques have since faded away to the stunning reliability of DNA forensics. In 1984, British geneticist Alec Jeffreys of the University of Leicester discovered an interesting new marker in the human genome. Most DNA information is the same in every human, but the junk code between genes is unique to every person. Junk DNA used for investigative purposes can be found in blood, saliva, perspiration, sexual fluid, skin tissue, bone marrow, dental pulp, and hair follicles (Butler, 2011). By analyzing this junk code, Jeffreys found certain sequences of 10 to 100 base pairs repeated multiple times. These tandem repeats are also the same for all people, but the number of repetitions is highly variable. Before this discovery, a drop of blood at a crime scene could only reveal a person’s blood type, plus a few proteins unique to certain people. Now DNA forensics can expose a person’s gender, race, susceptibility to diseases, and even propensity for high aggression or drug abuse (Butler, 2011). More importantly, the certainty of DNA evidence is extremely powerful in court. Astounded at this technology’s almost perfect accuracy, the FBI changed the name of its Serology Unit to the DNA Analysis Unit in 1988 when they began accepting requests for DNA comparisons (Using DNA to Solve Crimes, 2014).
cells, or blood cells the DNA found in one cell is identical to the DNA
DNA – the very molecule that defines who we are. It is still fascinating that a molecule that is so small that is not visible to the naked eye determines not just our physical appearance but also our mental wellbeing. Over 60 years, the discovery of the double helix DNA had impacted various fields relating to Biology and Chemistry, contributing to the advancement of technology and subsequently mankind too.
Discoveries in DNA, cell biology, evolution, and biotechnology have been among the major achievements in biology over the past 200 years, with accelerated discoveries and insight’s over the last 50 years. Consider the progress we have made in these areas of human knowledge. Present at least three of the discoveries you find to be the most important and describe their significance to society, health, and the culture of modern life. DNA (deoxyribonucleic acid) is a self-replicating molecule or material present in nearly all living organisms as the main constituent in chromosomes. It encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses.
For example such as medicine, it can be sometime possible to reading DNA sequences and find out how some diseases occur. It can sometimes be possible to fight some infectious diseases or any form of disease by changing the DNA codons which cause most of these problems.