...Structure and Function The word protein was first coined in 1838 to emphasize the importance of this class of molecules. The word is derived from the Greek word proteios which means "of the first rank". This chapter will provide a brief background into the structure of proteins and how this structure can determine the function and activity of proteins. It is not intended to substitute for the more detailed information provided in a biochemistry or cell biology course. Proteins are the major components of living organisms and perform a wide range of essential functions in cells. While DNA is the information molecule, it is proteins that do the work of all cells - microbial, plant, animal. Proteins regulate metabolic activity, catalyze biochemical reactions and maintain structural integrity of cells and organisms. Proteins can be classified in a variety of ways, including their biological function (Table 2.1). Table 2.1 Classification of Proteins According to biological function. | Type: | Example: | Enzymes- Catalyze biological reactions | ß-galactosidase | Transport and Storage | Hemoglobin | Movement | Actin And Myosin in muscles | Immune Protection | Immunoglobulins (antibodies) | Regulatory Function within cells | Transeription Factors | Hormones | Insulin Estrogen | Structural | Collagen | How does one group of molecules perform such a diverse set of functions? The answer is found in the wide variety of possible structures for proteins. In the...
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...may be reflected in the phenotype of the affected organism. The phenotype of an organism is its total appearance determined during development by an interaction between its genetic make-up (genotype) and the environment. A genome is all of the genetic material (DNA) within a cell and is specific to each organism. Genomes influence nearly all the traits or phenotypes. The phenotypic appearance is therefore directly affected by gene expression. The extent of phenotypic differences depends on how different the DNA sequences are in individuals, but may also be influenced by the environment. • Outline evidence that led to Beadle and Tatum’s ‘one gene-one protein’ hypothesis and explain why this was altered to the ‘one gene – one polypeptide’ hypothesis Beadle and Tatum carried out experiments with red bread mould. The normal variety of mould can manufacture certain substances that it needs for living, including vitamin B1, B2, B4 and B12. The normal moult possesses specific enzymes that catalyse the different reactions that produce these vitamins. Beadle and Tatum produced several varieties of the bread mould, each of which had a change in one of its genes. They tested these varieties and found that some had lost their ability to make vitamin B2 while others could no longer make vitamin B4 and so on. The results obtained by Beadle and Tatum showed that a change in various genes of the bread mould resulted in the loss of different enzymes and the failure of specific...
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...Q1 A cell’s genetic information or genome or DNA, either a single DNA molecule in prokaryotes or multi DNA molecules in eukaryotes always consist of chromosomes. In humans, a typical cell has about 3 meters of DNA which has to be copied and then this copy has to be separated during cell division. This can be done just because the DNA molecule can be packed into chromosomes (chromo means coloured). Every species has certain number of chromosomes in each nucleus, for example humans have 46 chromosomes in their somatic cells and half of this number, 23 in their sex cells or gametes. So then each chromosome has a long chain of a DNA molecule which has hundreds or thousands of genes and these genes are specified for numerous inherited traits. Many proteins in DNA help to maintain the structure of chromosomes and control the genes actions. This DNA-proteins complex forms a thin, long structure, called chromatin which coil and fold during cell division to make the chromosome much thicker and shorter. Each duplicated chromosomes contains two sister chromatid with identical copies of DNA molecule, attached at a narrow place called centromere. Later in cell division process the sister chromatids of all the chromosomes are pulled apart and repackaged as complete chromosome sets in two new nuclei. Mitosis or the division of the nuclei is usually followed by cytokinesis or the division of cytoplasm.Where there was one cell, now there are two cells each equivalent of the parent cell...
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...Review Biology Test #1 Chapter 3: Water and life • Polar covalent bonds in water result in Hydrogen bonding between the molecules. These bonds give water its special properties • In presence of water, ionic bonds are weak and covalent bonds are strong. Without water, ionic bonds are stronger. • Each water molecule can make 4 hydrogen bonds. • Water properties: 1. Polarity 2. Surface tension 3. Cohesion 4. Adhesion 5. Capilarity 6. High specific heat 7. Heat bank 8. Heat of vaporization allows evaporation cooling. 9. Abundant and versatile solvent 10. Solid is less dense than liquid 11. It is a reactant and a product in many biological reactions (Photosynthesis, dehydration reaction, hydrolysis…) 12. It can ionize into H3O+ and OH- • When substances dissolve in water, water molecules form hydration shells by breaking their attractions to other water molecules and attracting to the solvate particles. • The dissociation of water molecules into Hydronium and hydroxide ions is a reversible reaction that occurs in a state of equilibrium (pure water). • The concentration of each ion in pure water is 10-7 M. [OH-][H3O+] = 10-14 M. This way, whenever we know the concentration of one ion, we can calculate the concentration of the other. • Adding acids and bases can change these concentrations of ions in water • When acids dissolve in water, they donate H+, increasing the concentration of hydrogen ions. This results in an acidic solution • When bases dissolve in water...
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...1. Write an essay on protein structure and synthesis Protein synthesis is a cellular process leading to the production of proteins. This term is also synonymous to protein translation. It begins with a sequential process of transcription of DNA into mRNA, which is then used as input for translation after exon-intron splicing. The addition of successive tRNA molecules based on the code of mRNA matched up by base-pairing through their anti-codons in the ribosomes creates the nascent protein. After the protein chain has been synthesized, post-translation modification occurs, e.g. phosphorylation, motifs added to the protein. This may happen at various levels: secondary (alpha-helix, beta-sheets, turn, random coiling), tertiary and quarternary. Protein synthesis is also the process wherein peptide bonds between two amino acids whose formation is controlled. The synthesis begun when the mRNA combines in a little subunit of ribosomes close to an AUG sequence in mRNA. Start codon which is the AUG codon is being such because it does the coding of the first amino acid to be made of protein. “The AUG codon base-pairs with the anticodon of tRNA carrying methionine. A large ribosomal subunit binds to the complex, and the reactions of protein synthesis itself can begin. The aminoacyl-tRNA to be called for next is determined by the next codon (the next three bases) on the mRNA. Each amino acid is coded for by one or more (up to six) codons” (Center for Bioenergy and Photosynthesis...
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...Matitiahu Berkovitch et al. (2002). Colonization rate of bacteria in the throat of healthy infants. International Journal of Paediatric Otorhinolaryngology 63,19-24. Nucleic Acids Research, 2003, Vol. 31, No. 22 6516-6523.The complete genome sequence and analysis of Corynebacterium diphtheriae A. M. CerdenÄo-TaÂrraga et. al A. M. CerdenÄo-TaÂrraga et. al. (2003). The complete genome sequence and analysis of Corynebacterium diphtheriae . Nucleic Acids Research 31, 6516-6523. (A. M. CerdenÄo-TaÂrraga et. al., 2003) Corynebacterium diphtheriae is a Gram-positive,non-spore forming, non-motile, pleomorphic rod belonging to the genus Corynebacterium and the actinomycete group of organisms. The organism produces a potent bacteriophage-encoded protein exotoxin, diphtheria toxin (DT), which causes the symptoms of diphtheria. This potentially fatal infectious disease is controlled in many developed countries by an effective immunisation programme. Corynebacterium diphtheria was shown to be the cause of the acute, communicable disease diphtheria after being isolated from diphtheritic pseudomembranes in the late 19th century The virulent and toxigenic strains are lysogenic, and produce an exotoxin formed by two polypeptide chains, which is itself produced when a bacterium is transformed by a gene from the β prophage.[9] Nonpathogenic species of Corynebacterium are used for very important industrial applications, such as the production of amino acids,[19][20] nucleotides, and...
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...flask-fungi. The natural habitat of the three species of Sordaria that have been the principal subjects in genetic studies is dung of herbivorous animals. The species S. fimicola is common and worldwide in distribution. The species of Sordaria are similar morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination Eukaryotic cell cycle The division cycle of most cells consists of four coordinated processes: cell growth, DNA replication, distribution of the duplicated chromosomes to daughter cells, and cell division. In bacteria, cell growth and DNA replication take place throughout most of the cell cycle, and duplicated chromosomes are distributed to daughter cells in association with the plasma membrane. In eukaryotes, however, the cell cycle is more complex and consists of four discrete phases. Although cell growth is usually a continuous process, DNA is synthesized during only one phase of the cell cycle, and the replicated chromosomes are then distributed to daughter nuclei by a complex series of events...
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...pepsin, the powerful enzyme in gastric juice that digests proteins such as those in meat, eggs, seeds, or dairy products. Pepsin was first recognized in 1836 by the German physiologist Theodor Schwann. In 1930 it was crystallized and its protein nature established by John H. Northrop of the Rockefeller Institute for Medical Research. Glands in the mucous-membrane lining of the stomach make and store an inactive protein called pepsinogen. Impulses from the vagus nerve and the hormonal secretions of gastrin and secretin stimulate the release of pepsinogen into the stomach, where it is mixed with hydrochloric acid and rapidly converted to the active enzyme pepsin. The digestive power of pepsin is greatest at the acidity of normal gastric juice (pH 1.5–2.5). In the intestine the gastric acids are neutralized (pH 7), and pepsin is no longer effective. In the digestive tract pepsin effects only partial degradation of proteins into smaller units called peptides, which then either are absorbed from the intestine into the bloodstream or are broken down further by pancreatic enzymes. Small amounts of pepsin pass from the stomach into the bloodstream, where it breaks down some of the larger, or still partially undigested, fragments of protein that may have been absorbed by the small intestine. Pepsin is prepared commercially from swine stomachs. Crude pepsin is used in the leather industry to remove hair and residual tissue from animal hides prior to their being tanned. It is also...
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...Felician College Advanced Clinical Pathophysiology NURS 505 Dr. Tritak November 14, 2015 “ I pledge my honor that I have neither given nor received inappropriate aid on this assignment” Tay-Sach's Disease Disease and the deterioration it causes on the human existence is a tragic but inevitable phenomenon that man has dealt with throughout time. Death is unavoidable, yet the situation becomes evermore helpless when it strikes the young; the innocent who have not had their share of time, as is the case with a condition like Tay-Sachs disease. Fortunately, much childhood disease that plagued us for centuries has been eradicated due to the advances of modern science, and with the prospects of genetic technology today, the future is looking promising for those that have manage to elude scientists, like Tay-Sachs. However, Tay-Sachs is not a disease that can be considered in terms of science alone; it effects a unique ethnic population whose history and beliefs need to be considered in a sensitive manner. Tay-Sachs disease is a genetic disorder that is devastating in its deadliness. This rare fatal disease is passed down through families. The disease’s hyphenated name is the result of two doctors, who worked independently of one another in the late 1800s. Dr. Warren Tay, an ophthalmologist, was the first to characterize one of the tell tale signs of the disease, the retina of the eye has a cherry red spot. A New York, neurologist, Dr. Bernard Sachs provided the first...
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...93 7plummer, D T, Elliot, B A, Cooke, K B and Wilkinson, J H (1963) Biochem J 87,416-422 8Zubay, G (1993) Biochemistry, Third Edition, p 663, Brown', Dubuque, Iowa '~Rawn, J D (1983) Biochemistry, p 675. Harper and Row, New York "~Horton, H R, Moran, L A, Ochs, R S, Rawn, J D and Scrimgeour, K G (1993) Principles of Biochemistry. pp 12.20-21, Neil Patterson Publishers/Prentice Hall, Englewood Cliffs, New Jersey I I Werner, R (1992) Essential Biochemistry and Molecular Biology, Second Edition, pp 38-39, Elsevier, Amsterdam ~2Perham, R N (1993) Trends Biochem Sci 18, 270-271 ~3Bohinski, R C (1987) Modern Concepts in Biochemistry, Fifth Edition, p 5(19, Allyn and Bacon, Newton, MA ~4Conn, E E, Stumpf, P K, Bruening, G and Doi, R H (1987) Outlines of Biochemistry, Fifth Edition, p 354, John Wiley, New York I~Mathews, C K and van Holde, K E (1990) Biochemistry, p 449, Benjamin/Cummings, Redwood City, CA ~t'Voet, D and Voet, J G (1990) Biochemistry, p 444, John Wiley, New York ~7Wuntch, T, Chen, R F and Vesell, E S (1970) Science 167, 63-65 ~SVesell, E S (1975) In Isozymes edited by C L Markert, Vol 2, pp 1-28, Academic Press, New York 1"Burgher, J W, Ainslie, G R, Cleland, W W and Ray, W J (1978) Biochemistry 17, 1646-1653 -'°Cornish-Bowden, A and Cfirdenas, M L (1991) Trends Biochem Sci 16, 281-282 2~Blackstock, J C (1989) Guide to Biochemistry, pp 76-77, Wright/ Butterworth, London -~-'Newsholme, E A and Leech, A R (1983) Biochemistry for the Medical Sciences, pp 206-207, John Wiley...
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...takes in DNA from another source. C) a cell’s own DNA is inserted into a plasmid. D) a cell is mutated. 4. What does the figure to the right show? A) gel electrophoresis B) DNA sequencing C) a restriction enzyme producing a DNA fragment D) polymerase chain reaction 5. Which of the following is the region that is the binding site for RNA polymerase? A) heterogeneous nuclear DNA B) repressor gene C) promoter sequence D) operator sequence E) all of these 6. Probes for cloned genes use A) complementary nucleotide sequences labeled with radioactive isotopes. B) certain media with specific antibodies. C) specific enzymes. D) certain bacteria sensitive to the genes. E) all of these 7. When a gene transcription occurs, which of the following is produced? A) more DNA B) protein or polypeptide sequences C) messenger RNA D) enzymes E) genetic defects 8. The DNA fragments produced by automated DNA sequencing are identified using A) radioactive probes. B) laser beams. C) ultracentrifugation. D) electron microscopy. E) restriction enzymes. 9. The laboratory technique used to separate the DNA fragments produced by automated DNA sequencing is A) the polymerase chain reaction. B) gel...
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...2F-Pharmacy Biochemistry Laboratory ABSTRACT Chemical analysis can be either qualitative or quantitative in nature. In qualitative analysis, we work to identify the substances present in a given sample. We are only concerned whether certain substances are present or absent while in quantitative analysis, we are concerned in determining the amount of each component present in a sample. This experiment aims to isolate and characterize the intact protein in wheat flour which is Gluten through hydrolysis and chromatography. Gluten was isolated then hydrolyzed by proteolytic enzyme and was subjected to different qualitative tests. Paper Chromatography was also performed to analyze the different amino acid components of gluten. Tests showed that Gluten has several amino acid components. INTRODUCTION Proteins are a class of organic compounds which are present in and vital to every living cell. In the form of skin, hair, callus, cartilage, muscles, tendons and ligaments, proteins hold together, protect, and provide structure to the body of a multi-celled organism. In the form of enzymes, hormones, antibodies, and globulins, they catalyze, regulate, and protect the body chemistry. In the form of hemoglobin, myoglobin and various lipoproteins, they affect the transport of oxygen and other substances within an organism. It is also known as polypeptides, are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer...
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...How Cells Transmit Information and Transform with DNA and RNA Shelley Gutierrez, RNC Western Governors University Student ID: 391502 Sgutie6@wgu.edu How Cells Transmit Information and Transform with DNA and RNA All of our body cells are made up of 46 chromosomes. Each of the 46 chromosomes contains one DNA molecule. These chromosomes and proteins are found compressed in the nucleus of the cells. DNA and RNA are biological molecules that are nucleic acids. Both DNA and RNA are polymers. When polymers are linked together in DNA, they are called polynucleotides (Devlin, T. 2002). The polymers of DNA, known as nucleotides are composed of a phosphate group, 5 carbon sugar molecules, and 1 of 4 nitrogen bases. The four nitrogenous bases: adenosine, thymine, cytosine and guanine is where the genetic coding is found. DNA has twin molecules that twist together. This is known as the double helix. The double helix bonds with sugars and phosphates to form twin Strands. Chemically the sugar phosphate bonds travel down each side of the helix in opposite directions. One strand begins at the top of the 1st phosphate connected at the sugar molecules 5th carbon and ending where the next phosphate would go with the free end at the sugar’s 3rd carbon. This results in a pattern of 5 prime and 3 prime. The opposite occurs with the other strand resulting in a pattern of 3 prime and 5 prime. (Adams, R., & Knowler, J. 1986). Once they are bonded they are now known...
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...ans 777777 In object-oriented programming, polymorphism (from the Greek meaning "having multiple forms") is the characteristic of being able to assign a different meaning or usage to something in different contexts - specifically, to allow an entity such as a variable, a function, or an object to have more than one form. There are several different kinds of polymorphism. 1) A variable with a given name may be allowed to have different forms and the program can determine which form of the variable to use at the time of execution. For example, a variable named USERID may be capable of being either an integer (whole number) or a string of characters (perhaps because the programmer wants to allow a user to enter a user ID as either an employee number - an integer - or with a name - a string of characters). By giving the program a way to distinguish which form is being 2) A named function can also vary depending on the parameters it is given. For example, if given a variable that is an integer, the function chosen would be to seek a match against a list of employee numbers; if the variable were a string, it would seek a match against a list of names. In either case, both functions would be known in the program by the same name. This type of polymorphism is sometimes known as overloading. 3) Polymorphism can mean, as in the ML language, a data type of "any," such that when specified for a list, a list containing any data types can be processed by a function. (For example, if a...
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...The pre-ligand binding assembly domain: a potential target of inhibition of tumour necrosis factor receptor function Francis Ka-Ming Chan Building 10, Room 11N311, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892–1892, USA Correspondence to: Dr Chan (fchan@nih.gov) Abstract Signalling by the tumour necrosis factor receptors (TNFR) is thought to be mediated by the binding of the trimeric ligand TNF to three monomeric subunits of the receptor. This ligand induced trimerisation model of TNFR signalling is mainly supported by crystallographic data of the p60 TNFR-1 and TNF complex in which the trimeric ligand interdigitates between the individual receptor chains and prevents the receptor subunits from interacting with each other. Recently, a domain NH2terminal to the ligand binding domain in the extracellular region of p60 TNFR-1, p80 TNFR-2 and Fas was identified that mediates receptor self association before ligand binding. This pre-ligand binding assembly domain or PLAD is critical for assembly of functional receptor complexes on the cell surface and may provide a potential target in the design of future novel therapeutics against diseases mediated by members of the TNFR family of receptors. (Ann Rheum Dis 2000;59(suppl I):i50–i53) Tumour necrosis factor (TNF) is a cytokine that plays an important regulatory part in both healthy and diseased immune responses.1 2 TNF signals through two distinct...
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