Dna Replication Essay, Research Paper
DNA replication is a complex cellular function that is necessary in order to sustain life and achieve growth. Many enzymes, proteins, and other molecules work together to ensure that genetic information is replicated efficiently, quickly, and accurately. Without any one of these components, replication would be very limited in its efficacy.
DNA is comprised of two strands of complementary nitrogenous bases (adenine & thymine, guanine & cytosine), five-carbon sugars (either ribose or deoxyribose), and phosphate groups. The strands of DNA are arranged in a double-helix array and are held together with hydrogen bonds. The semiconservative replication model is used to depict replication. In this model, each new double helix has one “old” strand and one “new” strand. This is yet another way in which accuracy is ensured.
Because the shape of the DNA molecule is extremely important to its functionality, care must be taken to ensure that all parts of the molecule remain in their appropriate space during replication, and that no part of the strand is broken. To replicate DNA, the two strands must first be separated from one another. The first enzyme used in this process is called helicase. Helicases use the energy from ATP molecules to unwind the three-dimensional double helix. While the strand is unwinding, topoisomerase enzymes (such as gyrase) prevent the strands from being winded into a supercoil due to the torque produced by the separating action. Since each strand is comprised of complementary base pairs that have a high affinity to hydrogen-bond with one another, single-stranded binding proteins (SSBs) are attached to the strands to keep them from reattaching to one another.
Once the strands are separated, work can begin to construct two new complementary strands that will ultimately attach to the existing DNA strands to form new complete DNA sequences. DNA polymerase III is the active enzyme that builds the new complementary strands. DNA polymerase III is a DNA-dependent enzyme. As such, a template (the existing separated strand) must be present to generate the new strand. DNA polymerase III requires a primer to begin its action. The primer used is a short RNA sequence with a 3′ hydroxyl group that is formed by an enzyme known as primase. This primer is usually about ten nucleotides in length and is complementary to the existing DNA strand. DNA polymerase always works in the same direction: from the 5′ end to the 3′ end.
Since DNA polymerase III always works in the 5′ to 3′ direction, and DNA strands are complementary, this gives rise to a few minor issues that must be dealt with. The strand in which DNA polymerase can move in the same direction as gyrase (with the replication fork) is known as the leading strand. As the strand is unwound, DNA polymerase III can easily begin to replicate the strand, as the replication fork is already moving in the 5′ to 3′ direction. The complementary strand is known as the lagging strand. The replication fork is necessarily moving in the 3′ to 5′ direction on this strand. On this strand, numerous primer sequences are inserted so that the DNA polymerase III can “backtrack” to build the new sequence as the strand is unwound. The DNA sequences between these primers, which are 1000 to 2000 nucleotides long, are known as Okazaki fragments.
Once DNA polymerase III has replicated the fragments, the need arises to remove the RNA primer sequences and fuse the portions of the new strand together. The first critical enzyme used to do this is known as DNA polymerase I. This enzyme removes the primer sequence with the crucial 3′ hydroxyl group and synthesizes complementary DNA to fill in the gaps left by the primers. After this is completed, yet another enzyme known as ligase is used to join the fragments. This enzyme works by forming a phosphodiester bond between the 3′ hydroxyl of the new strand and the 5′ phosphate group found on the Okazaki fragment. Using each enzyme to perform a specific function, DNA is successfully replicated.
Другие работы по теме:
Hjkhg Essay Research Paper ts and biochemical
Hjkhg Essay, Research Paper ts, and biochemical pathways. In comparing the organism 60% of M. jannaschii’s coding regions did not correlate with the known sequence database. 40% of the coding regions match the sequences of
Dna To Rna Essay Research Paper DNA
Dna To Rna Essay, Research Paper DNA to RNADeoxyribonucleic acid and ribonucleic acid are two chemical substancesinvolvedin transmitting genetic information from parent to offspring. It wasknown early into the20th century that chromosomes, the genetic material of cells, containedDNA. In 1944,Oswald T.
Romeo An Juliet Essay Research Paper hi
Romeo An Juliet Essay, Research Paper hi i need an essay about a character in romeo and juliet that demonsrtated maturity. in a well developed multi pagraph essay and say why you think the character’s maturity was greater than the other characters in the play.
Cloning 2 Essay Research Paper Cloning
Cloning 2 Essay, Research Paper Cloning The new breakthrough of cloning is a great advance in biotechnology. The use of cloning can be both beneficial and harmful to society. There are many reasonable ways to use the methods of cloning. For instance, the use for medical purposes can be helpful in cases such as producing animals with human body systems that could be used for transplanting organs.
Nanotechnology Essay Research Paper Let me say
Nanotechnology Essay, Research Paper Let me say it right now. Everything you thought was the limit of human kind is wrong. The strongest weapon is not the nuclear bomb. The strongest material is not steel. Your brain is not the fastest computer on the earth. The sky is not the limit. Humanity has not reached it full potential.
Mitochondria Essay Research Paper Mitochondria are the
Mitochondria Essay, Research Paper Mitochondria are the cells power sources of the cell. They are distinct organelles with two membranes. Usually they are rod-shaped, however they can be round. The mitochondria are organelles enclosed in a double membrane of phosphoglycerides. Between the two membranes of the mitochondrion lies a region known as the intermediate space.
Cloning A Dangerous Science Essay Research
Paper Cloning is a new science that has much to offer. We can learn how to grow and harvest organs, which would eliminate the waiting list for those in need of a heart, liver or other vital organs. Many are worried that cloning will be used for the wrong purposes such as creating multiple copies of one person for the purpose of war.
Reproducibility Of Man Essay Research Paper Reproducibility
Reproducibility Of Man Essay, Research Paper Reproducibility of Man When Walter Benjamin wrote The Work of Art in the Age of Mechanical Reproduction in 1969, I am sure he didn t expect it to parallel the arguments of today s discussions on the ethics of cloning. In the short shadow of the replication of Dolly the sheep, and five little piglets from Virginia comes the discussion on if this practice should really be allowed, and if so, what limits do you set? How can you look in the eyes of people who have had there family members pass away because the cloning of pigs for their organs have been outlawed.
Oh Really Essay Research Paper Oh Reallyyou
Oh Really? Essay, Research Paper Oh Really, you think i am a lark, the dogs they run and bark, but when i say to them, shut up shut up shut up, you say to be nice to them,
Aids Essay Research Paper AidsAcquired Immunodeficiency Syndrome
Aids Essay, Research Paper Aids Acquired Immunodeficiency Syndrome, or AIDS, is a very recognizable disease in the United States and all other parts of the globe. Being one of the most deadliest diseases to man, AIDS is feared because it brings certain death and currently, there is no cure. Unlike other diseases such as Tuberculosis and Malaria, AIDS is actually not the causal factor of death.
Antibiotics Essay Research Paper 46 Antibiotics
Antibiotics Essay, Research Paper 46. Antibiotics Antibiotics are chemical compounds used to kill or inhibit the growth of infectious organisms. Originally the term antibiotic referred only to organic compounds, produced by bacteria or molds, that are toxic to other microorganisms. The term is now used loosely to include synthetic and semisynthetic organic compounds.
Dna Age Altering Essay Research Paper Scientists
Dna Age Altering Essay, Research Paper Scientists Find New Lease of Life Scientists in the United States say they have been able to make human cells live longer by altering their genetic material. The research may offer renewed hope for age-related illnesses and the fight against cancer.
Economic Methods Essay Research Paper MethodsThe majority
Economic Methods Essay, Research Paper Methods The majority of the info that we found was form the website of The U.S. Department of Commerce Bureau of Economic Analysis (www.bea.gov). Tables A-1 thru A-5 give the per capita income from 1995 until 1999, respectively.
Clone Or Not To Clone Essay Research
Paper ?To Clone, Or Not To Clone?? Did you ever imagine having a child that is the exact replica of you? Did you ever imagine of having the cure for heart disease or cancer? Well, these fantasies are not far from reach. The way we could reach these fantasies is through a process called cloning. Cloning is the replication of an exact genetic copy of an organism by use of a somatic tissue (or cell) from the donor organism.
The Globe Theater Essay Research Paper globe
The Globe Theater Essay, Research Paper globe theatere The origins of the first Globe have many interesting details that make up its history. London developed a demand for entertainment and theaters. Europeans took the chance and began to build them. In 1576 the first successful theater was in operation in London.
Nuclear Protein Membrane Essay Research Paper 1
Nuclear Protein Membrane Essay, Research Paper 1. The nuclear envelope is a double membrane extension of the rough endoplasmic reticulum containing many nuclear pore complexes. The lipid bilayer of the inner nuclear membrane is supported by the nuclear lamina,a mesh work of lamin filament located adjacent to the inside face of the nuclear envelope.(Lodish et al 1997) The lamina is proposed to be involved in both organizing chromatin and in DNA replication in interphase cells (Gerace and Burke, 1988).
Genetic Engineering Essay Research Paper Generic EngineeringBioengineering
Genetic Engineering Essay, Research Paper Generic EngineeringBioengineering, or genetic engineering is an altering ofgenes in a particular species for a particular outcome.It involves taking genes from their normal location in oneorganism and either transferring them elsewhere or puttingthem back into the original organism in different combinations.Most biomolecules exist in low concentrations and as complex, mixedpopulations which it is not possible to work efficiently.
Hhv8 Essay Research Paper Human Herpes Virus8
Hhv-8 Essay, Research Paper ?Human Herpes Virus-8 (HHV-8) and Kaposi?s Sarcoma (KS)? Human herpes virus (HHV-8) poses a challenging task for researchers determining its role in Kaposi?s sarcoma (KS). People with KS are distinguished by their placement in four categories. The first category consists of elderly males of Mediterranean or Eastern European Jewish descent.
Dna 4 Essay Research Paper The molecule
Dna 4 Essay, Research Paper The molecule responsible for the transformation of characteristics form one generation to the next is called DNA. The genetic material, located in the chromosomes is a combination of acid and histones. DNA is made up of units called nucleotides. Nucleotides are made up of 3 components, a five carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base.
Werner Syndrome Essay Research Paper Psychology 261Instructor
Werner Syndrome Essay, Research Paper Psychology 261 Instructor: Ms Anne Thomas, M.A. October 5, 2000 Page 1 Imagine in your early adolescents being diagnosed with a disease that increases your aging. Doctors tell you that there is no known cure and that you will die by the age of fifty. There is a disease that increases your aging, that disease is known as Werner Syndrome.
Mitosis And Meiosis Essay Research Paper Mitosis
Mitosis And Meiosis Essay, Research Paper Mitosis and Meiosis : how they are similar and different Mitosis and Meiosis are alike in many ways essentially they are both forms of cellular reproduction. Both go through similar cellular division stages. Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis all occur in both Mitosis and Meiosis.
Mitosis Essay Research Paper MitosisThe Process of
Mitosis Essay, Research Paper Mitosis The Process of Mitosis is the term used to describe cell division for replication. The product at the end of mitosis is two daughter cells both genetically identical to the original (parent) cell. This process is used for growth and repair within an organism and also for asexual reproduction.
A Virus Essay Research Paper A virus
A Virus Essay, Research Paper A virus is an ultramicroscopic infectious organism that, having no independent metabolic activity, can replicate only within a cell of another host organism. A virus consists of a core of nucleic acid, either RNA or DNA, surrounded by a coating of antigenic protein and sometimes a lipid layer surrounds it as well.
Andrew Warhol Art Or Not Art Essay
, Research Paper The American artist Andy Warhol was born Andrew Warhola in 1928. There has been quite a bit confusion to where and when Andy Warhol was born, but according to Andy’s birth certificate that was filed in Pittsburgh in 1945, he was born on August 6th in Pittsburgh. Whether or not this is the day he was born hasn’t been proved, but it was on this day he would celebrate his birthday.
Potential Mutagens Essay Research Paper Ames testObjective
Potential Mutagens Essay, Research Paper Ames test Objective: “A mutagen is a chemical that mutates or alters DNA.” Many times, mutagens may be carcinogens as they may induce cancer. Dr. Bruce Ames developed a method by using specific mutant strains of the bacteria Salmonella typhimurium to detect mutagens and possible carcinogens.
Do Viruses Help Essay Research Paper HOW
Do Viruses Help? Essay, Research Paper HOW ABOUT VIRUSES? Just like bacteria viruses are one of the microbes that are winning the match against the humans. Viruses were the toughest one to tackle for the scientist. The shape, contents and their protective shields were the most challenging part of the fight.
The Modern Synthesis Genetics Darwin Essay Research
Paper The Modern Synthesis is the theory used to explain and predict all of the traits, variation and changes in living things. It combines the older theories of evolution and Mendelian genetics with more recent discoveries in molecular genetics and cellular biology. Pheno- and genotypical changes can be explained and observed on the molecular, cellular, individual and populace scale through the modern synthesis.
Protein Synthesis Essay Research Paper Protein SynthesisThe
Protein Synthesis Essay, Research Paper Protein Synthesis The Expression of a Gene The process of Protein Synthesis involves many parts of the cell. Unlike other similar productions, this process is very complex and precise and therefore must be done in proper sequence to work effectively. The slightest error during this process could cause the action to experience difficulty or even fail.
Dna Structure Essay Research Paper DNA Structure
Dna Structure Essay, Research Paper DNA Structure DNA is a double stranded molecule twisted into a helix. Each spiraling strand is comprised of a sugar phosphate backbone and attached bases connected to a complimentary strand. The complimentary strand is connected by non-covalent hydrogen bonding between paired bases.