DNA Fragmentation in Sperm Cells

DNA Fragmentation in Sperm Cells: Review Article DNA fragmentation in sperm cells is a relatively new concept that has discovered that the probability of conception occurring is partly dependant on the quality of the male partner's sperm cells. Earlier, it was believed that if a man had sperm that was live, motile and had a normal morphology, then an inability of the female partner to get pregnant through IVF?ICSI was probably due to the quality of the female egg tissue. However, then couples began to discover that even if they used surrogates or the eggs of established donors, they were unable to conceive. Then the concept of DNA fragmentation was introduced, which stated that the quality of the sperm is also dependant on the amount of damage done to its DNA or the amount in DNA fragmentation. The DNA in all cells is arranged in the form of a double helix, a structure that looks like a twisted ladder. If the rungs of this ladder break then the DNA will be unable to function properly. Not only that, but a sperm cell with high DNA fragmentation may not show any outwardly sign, i.e., neither its motility nor its morphology may be affected. (1) Thus, although several studies have shown that there is a high correlation between the degree of DNA fragmentation and the probability of normal pregnancy and childbirth, there are still some studies that say that although there is a

  • Word count: 801
  • Level: University Degree
  • Subject: Biological Sciences
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INDUSTRIAL USE OF ENZYMES

6.54.2.10 INDUSTRIAL USE OF ENZYMES Matti Leisola, Jouni Jokela, Ossi Pastinen, Ossi Turunen Laboratory of Bioprocess Engineering, Helsinki University of Technology, Finland, and Hans Schoemaker, DSM Research, MD Geleen, The Netherlands Keywords: Industrial enzymes, speciality enzymes, protein engineering, enzyme technology, enzyme production, biocatalysis, fine chemicals Contents . Historical background 2. Enzyme classification 3. Enzyme production 3.1. Microbial production strains 3.2. Enzyme production by microbial fermentation 4. Protein engineering 5. Enzyme technology 6. Large scale enzyme applications 6.1. Detergents 6.2. Starch 6.3. Drinks 6.4. Textiles 6.5. Animal feed 6.6. Baking 6.7. Pulp and paper 6.8. Leather 7. Speciality enzymes 7.1. Enzymes in analytics 7.2. Enzymes in personal care products 7.3. Enzymes in DNA-technology 8. Enzymes in fine chemical production 8.1. Chirally pure amino acids and aspartame 8.2. Rare sugars 8.3. Semi synthetic penicillins 8.4. Lipase based reactions 8.5. Asymmetric synthesis 8.6. Enzymatic oligosaccharide synthesis 9. Future trends in industrial enzymology Glossary Alkaline phosphatase: An enzyme that degrades ester bonds in alkaline conditions. Amino acid amidase: An enzyme that is used in manufacturing optically pure amino acids. It hydrolyses an amide bond in natural

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  • Level: University Degree
  • Subject: Biological Sciences
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Polymerase Chain Reaction, or PCR Applications.

PCR Applications Polymerase Chain Reaction, or PCR, is a procedure that was invented in the late 1980's and is widely used in the selective amplification of a chosen region of a DNA molecule. This chosen region can be from any part of the DNA molecule, however PCR will only work if the base sequences of the 3' and 5' ends are known. This is to ensure that two short oligonucleotides, acting as primers, can anneal onto the DNA strands and initiate DNA synthesis reactions. The process of PCR is dependant on the thermostable DNA pol I enzyme from the bacterium Thermus aquaticus The basic procedure of PCR is several cycles of denaturation, hybridisation and synthesis resulting in the eventual synthesis of several hundred million copies of the amplified DNA fragment (see Fig.1 for the overall stages of PCR). Following its completion, a sample of the mixture is analysed by agarose gel electrophoresis, where it is visible as a discrete band by staining with Ethidium Bromide. Fig.1 Summary of PCR PCR is a very sensitive technique and because of this it is used worldwide in molecular biology. There are many applications of PCR, all of which have aided the current knowledge into DNA sequencing and cloning. PCR is frequently used when screening gene libraries after standard cloning experiments. This method can identify and isolate a clone carrying a particular region of the

  • Word count: 868
  • Level: University Degree
  • Subject: Biological Sciences
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DNA fingerprinting and its use in crime detection.

DNA fingerprinting and its use in crime detection This essay will discuss the issues surrounding the use of DNA fingerprinting in the prevention of crime. A description of the methods used to create a DNA fingerprint and the retrieval of DNA evidence from crime scenes. The current debates over the validity of DNA fingerprinting and its use as evidence in the courtroom also the ethical problems surrounding the present DNA database. In humans, a DNA molecule consists of two strands that wrap around each other to resemble a ladder whose sides, made of sugar and phosphate molecules are connected by rungs of nitrogen-containing chemicals called bases. Each strand is a linear arrangement of repeating similar units called nucleotides, which are each composed of one sugar, one phosphate, and a nitrogenous base. Four different bases are present in DNA, which are adenine thymine cytosine and guanine. The particular order of the bases arranged along the sugar-phosphate backbone is called the DNA sequence. This sequence specifies the exact genetic instructions required to create an organism with its own unique traits. The two DNA strands are held together by weak bonds between the bases on each strand, forming base pairs. Genome size is usually stated as the total number of base pairs, the human genome contains roughly 3 billion base pairs. Humans have 23 pairs of chromosomes

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  • Level: University Degree
  • Subject: Biological Sciences
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The Emergence of SNPs in Genetic Medicine.

The Emergence of SNPs in Genetic Medicine Name: Simpson Chan Student # 992452458 TA Name: Rahul Tutorial: L0101 B, Tues 1-4 Forensic DNA and Ancient DNA Since the discovery of techniques that allow for DNA analysis and sequencing, not only did it impact the field of genomics, but it also stimulated other fields of applications. (Capelli et al, 2003). Two unconventional and ways of applying these techniques, ancient DNA (aDNA) analysis and forensic DNA profiling (Capelli et al, 2003), are branches of this discovery that intertwine in respect to their methodologies and approaches. In this commentary, I will attempt to analyze the criteria of authentication, the different aspects of the purpose of DNA analysis, and the problems regarding contamination of the two unconventional applications of DNA analysis. DNA analysis has become an effective procedure in forensic genetics. Prior to 1985, the methods of analyzing biological samples were limited to only conventional blood group and enzyme analysis in criminal cases (Capelli et al, 2003). These methods were informing but nevertheless only gave surface analysis. The advent of the polymerase chain reaction (PCR) changed this phenomena and made DNA analysis an endless scope applicability. Capelli et al states that it allowed forensic experts to address the most inaccessible sources of DNA evidences (such as cigarette butts,

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  • Level: University Degree
  • Subject: Biological Sciences
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Comparison of Traditional and Modern Approaches to the Identification of Bacteria.

Comparison of Traditional and Modern Approaches to the Identification of Bacteria Wei Na (ID: 329877) Correspondence: Tel: 0121 257 1044 E-mail: [email protected] The practical Report is for BSM 236 Microbes and Man. Department of Biological Science. The University of Birmingham ABSTRACT INTRODUCTION Classification and identification of organisms are two separated but inter-related processes. Classification involves the identification of groups of organism that share common properties and that differ from other groups. The classification and identification of organisms are two separate but inter-related processes. Classification involves the identification of groups of organism that share common properties and that differ from other groups. Identification entails the assignation of an unknown organism to a group within a scheme of classification. Classification Classification is the process of recognizing and describing groups of living organism. Classification is important. It is an activity essential to all scientific work. It would be impossible to make any generalizations about microorganisms and their role in nature if we could only refer to each strain by a different and arbitrary name. We must arrange microorganisms into groupsthat share common properties, so that we can talk about sets of strains that have properties in common. Identification

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  • Level: University Degree
  • Subject: Biological Sciences
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In heart diseases, time only makes a physical injury worse. If starved for oxygen

Ceren Yalaz 10-6 11.11.2005 Abstract of "Rebuilding the Heart" (1) In heart diseases, time only makes a physical injury worse. If starved for oxygen, heart cells die, their places filled not by fresh replacements but by scarring. Burdened with useless tissue, the heart needs to work harder to pump the blood. The overworked heart gets bigger and it can never catch up with its old pace. Despite doctors' efforts to save them with drugs, catheters, stents and surgery, 5 million Americans currently suffer from heart failure. So cardiologists have started shoring up the dying hearts with stem cells, immature cells that can be coaxed into transforming into many different types. In spite of the encouraging results of the experimental surgeries, noone knows how the treatment works. How the stem cells renew the tissue or the side-effects, are unkown. There are many experiments done on this issue: 1)mice who -deliberately caused to- suffer heart attack, cured by transmission of bone marrow rich in stem cells. 2)In Gremany, the hearts of 60 patients, who suffered heart diseases, were transmitted bone marrows by catheters; their hearts pumped more blood, strongly. 3)In Pittsburgh University, 100 patients' hearts pumped more blood after stem cell treatment, without any side-effects. 4)In Equador Republic, 10 patients with were ejected stem cells obtained from the fetus.

  • Word count: 768
  • Level: University Degree
  • Subject: Biological Sciences
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Genetic-Fingerprint or DNA-profiling

Genetic-Fingerprint or DNA-profiling DNA profiling is only possible because we have within the non-coding regions between genes short sequences of bases called core sequences. They repeat themselves over and over again (up to 100 times). These repeated regions of DNA are called minisatellites (or variable number tandem repeats), and each individual has different numbers of repeated core sequences. DNA-profiling is based on two observations: - The number of repeats of a core sequence tends to vary considerably from person to person (the greater the no. of repeats, the longer the minisatellites, therefore each individual has different sized minisatellites). - Each individual has 50-100 different types of minisatellites made from different core sequences. It is almost impossible to find two individuals having matching minisatellites all of the same length (only they would be identical twins), there is only the chance to find very similar minisatellites. Therefore it is important to choose some that show the most variation between people. Making a DNA fingerprint There are 4 main steps for making a DNA fingerprint: Extraction › digestion › separation › hybridisation Extraction A sample of tissue containing cells with a nucleus (e.g. blood, a hair root or semen containing a few sperm cells) is taken to the laboratory where DNA is extracted by shaking the sample in

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  • Level: University Degree
  • Subject: Biological Sciences
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Who were the Neanderthals? Discuss the importance of genetic evidence for understanding Neanderthal extinction

Who were the Neanderthals? Discuss the importance of genetic evidence for understanding Neanderthal extinction. Neanderthals, a species of Homo Neanderthalensis originated in Europe and parts of western Asia from about 230,000 to 29,000 years ago, during the Palaeolithic period. The relatively large number of Neanderthal fossils and their good preservation offers the possibility of healthy assumptions about their evolution and paleobiology. Nevertheless, debate still continues on important issues, and this suggests that deeper hypothetical and methodological differences lie at the root of the lack of agreement. Such disagreements are not likely to be determined by further fossil findings, but rather require critical re-evaluation of the evidence at hand and the purpose of novel techniques and perspectives. The Neanderthals are best known ancient humans for two of the main reasons. Firstly, they lived in the region which has been explored more than any other for its prehistory- Europe. Secondly, many of them lived in caves, and they adopted the habit of burying their dead in the caves in which they lived. This has meant that Neanderthal bodies have had a greater chance of becoming fossilized, since they were protected by burial from destruction through erosion, trampling or scavenging. Moreover, it is these caves that can also hint at intricacy on how these Neanderthals

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  • Level: University Degree
  • Subject: Biological Sciences
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Describing how the structure of DNA is suited to its role in Cell Division and Protein Synthesis.

Matt Walker 12GIR Describing how the structure of DNA is suited to its role in Cell Division and Protein Synthesis. DNA is found in every cell nucleus. The nucleus contains genetic codes, these codes decide a species inherited characteristics. Cell division is a process of replacing lost or damaged cells and aiding growth. To produce new cells proteins need to be manufactured this is done by a process called Protein Synthesis. The role of DNA in these two processes is very important. DNA controls the manufacture of proteins and these proteins are what make us unique. Therefore it is important to understand the structure of DNA and how it is suited to its role in these two processes. Structure of DNA A strand of DNA is made up of a double helix. When it is unwound it consists of phosphate, sugar and one of four organic base/nitrogen molecules called nucleotides. The sugar and the phosphate form the two strands along the sides of the helix and the bases are joined by hydrogen bonds that form ties like rungs on a ladder. The role of DNA in Cell Division DNA is found in the cell nucleus, which has a Nuclear Envelope Pore. The role of DNA is to provide instructions for proteins to be produced in the cytoplasm. However, DNA can't pass through the Nuclear Envelope Pore of the nucleus to the cytoplasm. Therefore the DNA has to pass accurate instructions from the nucleus to

  • Word count: 590
  • Level: University Degree
  • Subject: Biological Sciences
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