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University Degree: Cell Biology

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  1. Marked by a teacher

    Prokaryotes and Viruses

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    Gram staining is a method of staining used to indentify and classify different bacteria. The process itself is used to differentiate between two major cell wall types present in bacteria. These are gram negative and gram positive. Gram-negative bacteria having cell walls that contain small amounts of peptidoglycan and lipopolysaccharide, where as gram-positive bacteria have large amounts of peptidoglycan and no lipopolysaccharide.3 The process itself is as follows. First a sample of must be obtained then heated to actually kill the bacteria so it can be worked on.

    • Word count: 924
  2. This experiment was carried out to characterize an enzyme, -amylase by extracting it from the corn. The factors affecting the enzymatic activity of -amylase such as substrate concentration, temperature, pH, ionic strength and inhibitors were inves

    Different types of enzymes have different pH range and temperature that allows the activity of enzyme to be carried out optimally. When pH increases, the acidity decreases since the concentration of hydrogen ions decreases. As a result, since the increasing amount of hydroxyl ions compete against the enzymes' ligands for divalent and trivalent cations to form hydroxides and thus affecting the enzymatic activity (Pandey et al., 2006). This applies to low pH value too due to the increase in hydrogen ions as the ionic bonding that maintains the shape of the enzyme will be altered causing the enzyme to be denatured.

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  3. The Effect Of Osmosis In Animal Cells, Plant Cells & A Model System

    In this case, the concentration of solute in the cell is equal to the concentration of the fluid that surrounds the cell (Bowen, 2000). When this happens the flow of water molecules into the cell is equal to the flow of water molecules coming out of the cell which results in no net movement (Karp, 2010). A hypertonic solution is a solution that contains a higher concentration of solute over the solution being compared to (Bowen, 2010). In this case, if the fluid surrounding the cell has a higher concentration of solute compared to the inside of the cell than the water leaving the cell is greater than the water entering the cell (Karp, 2010).

    • Word count: 1897
  4. Identifying different biological macromolecules

    Carbohydrates are simply molecules that are made up of sugars (Garcia, 2002). Their molecules contain simple elements like carbon, hydrogen and oxygen and an example of a carbohydrate would be glucose (Garcia, 2002). Within living organisms like ourselves, proteins are considered to be very diverse and complex molecules (Garcia, 2002). Some things that are composed of proteins include muscle tissue, blood cells and enzymes (Garcia, 2002). Like carbohydrate molecules, protein molecules also contain simple elements like carbon, hydrogen and oxygen but these molecules also contain nitrogen as well (Garcia, 2002).

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  5. Describe the structure of keratin and collagen and show how their structures are suited to their biological functions. Discuss one disease/ metabolic disorder that can arise from a structural defect in either protein.

    These include the skin, hair, nails, as well as horns and hooves in animals. The variety of body compounds that contain keratin show that it is a material that varies depending on function. In relation to skin, the amino acids, which make it up are arranged differently from any other form of keratin and make up the soft layer known as skin. It is present in all epithelial cells, those on the outer surface and on the inner surface such as the lining of the digestive tract. On the other end of things nails contain keratin, which are very hard.

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  6. Investigation into the integrity of cell membranes under different conditions

    These are all placed on a test tube rack and placed on the side somewhere. Next using boring tool 11 cylinders of beetroot should be cut from the beetroot. The cylinders should measure approximately two cm in length and 1 cm in diameter. The cylinders should be rinsed under tap water until the water begins to run clear, indentifying that the pigment from the damaged cells in the cutting process have been washed away. After this five of the cylinders should be placed in test tubes that have been left in water baths with varying temperatures from 30?C to 70?C.

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  7. Virtual Investigation of an Enzyme. A new protease (ref. no PR/66-430-010), isolated from B.yorkii has been characterised. A series of experiments were run on the enzyme to determine the optimum pH for the enzyme to run at, the effect of pH on KM and Vmax

    The optimum pH was found to be pH 7.0 Results Fig.1 shows that the optimum pH at which the enzyme works at was pH 7.0. Fig.2 is a Lineweaver-Burk plot of the reciprocal values of the enzyme recorded at ph 7.0, with all values constant other than the concentration of the substrate. The Vmax and Km of the enzyme under inhibitor influence, double inhibitor and a control of no inhibitor were calculated from the lines of best fit on the plot and are as follows.

    • Word count: 589
  8. Investigation Of The Respiratory Chain In Mitochndria. The experiments were carried out to investigate electron transport of the respiratory chain of yeast mitochondria and to examine the effects of different compounds on the chain. This was done using s

    Experiment B (Part 2) Experiment B (Part 3) 0 0.91 0.84 0.75 1 0.86 0.84 0.61 2 0.81 0.83 0.54 3 0.77 0.825 0.52 4 0.73 0.825 0.515 5 0.685 0.815 0.515 6 0.65 0.81 0.51 7 0.61 0.805 0.51 8 0.58 0.805 0.51 9 0.55 0.8 0.51 10 0.515 0.795 0.5 11 0.49 0.79 0.5 12 0.47 0.785 0.5 13 0.44 0.785 0.5 14 0.42 0.78 0.495 15 0.4 0.75 0.495 Experiment A Rate DCPIP reduction calculations: Part 2 = 0.96-0.96 / 5 = 0 / 263 x 1000 = 0 nmol-1 min-1 Part 3 = 0.95-0.935 / 5

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  9. Proteins. The experiment aimed to extract proteins from green papaya through salting out with the use of ammonium sulfate. Ultrafiltration was then done in preparation to ion-exchange chromatography which would be employed to purify the crude protein extr

    In this experiment, green papaya was utilized as the source of protein. Green papaya is the unripe fruit of the plant Carica papaya which is native to the tropics of the Americas. Green papaya fruit is rich in an enzyme called papain. Papain is a protease commonly used in tenderizing or breaking down tough meat fibers. III. Discussion: Protein Extraction. In this experiment, proteins from green papaya would be extracted. To isolate the proteins, the tissue would be washed and lysis method or homogenization would be employed to disrupt the tissues. This can be accomplished by chopping the tissue in a blender or by forcing the tissue through a narrow opening between a Teflon pestle and a glass container.

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  10. The solubilisation and purification of an intrinsic membrane protein presents problems distinct from those encountered in purifying a conventional soluble protein. Discuss this statement.

    The required strength of the elution buffer depends on the proteins' isoelectric points, so by increasing the strength of the buffer, different proteins can be eluted at different times. Affinity chromatography works in a similar, but more specific way. Resin beads are labelled by antibodies which bind specific proteins. The proteins are then eluted by a buffer containing a secondary antibody which competes with the stationary antibody binding the protein, allowing the protein to elute. A high salt concentration can also be used to elute the protein by disrupting the non-covalent forces which attach it to the primary antibody.

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  11. MonoMUSCLES AND NERVES lab report

    Greater diameter and more branches of the Coronary Arteries could bring more oxygenated blood to the cardiac muscle in order to carry out forceful contraction. It carries blood to the right part of the heart, including right atrium and right ventricle, which pumps blood to the pulmonary circulation. The distance traveled by the blood they pump out is shorter.

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  12. In Relation to human cells

    (Gunn p.3) These entire three cells merge together to create the process known as Ossification (Osteogensis) meaning bone formation. Ossification is described in two processes Intramembranous Ossification; which highlights the bone growth of an infant and Endochondral Ossification; examines the bone formation in cartilage.(Patton & Thibodeau p.200) The human embryo is primarily constructed of fibrous membrane and hyaline cartilage just before week eight. From week 8 onwards the fibrous connective tissue membrane which is constructed by mesenchymal cells begins to develop into bone tissue, the development of bone from fibrous membrane is known as intramembranous Ossification. When these mesenchymal cells cluster together osteoblasts are produced and an ossification centre becomes apparent.

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  13. Skin Cancer

    Basal cell skin cancer usually forms due to years and years of skin damage. Therefore, it is most often found on the sun-exposed areas of older adults. Such areas include the nose, face, back, and neck. Basal cell carcinoma is definitely curable with treatment. The second most common form of skin cancer is squamous cell carcinoma. Men over age 55 are most likely to develop this type of the disease. Squamous cell skin cancer usually develops over time. Similar to basal cell carcinoma. This type is usually found on areas that have endured many years of sun exposure (Skin Cancer Guide).

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  14. Free essay

    A good quality image is the key factor to a successful abdominal x-ray.

    Knowlodge of these factors assist the radiographer in achieving the best quality image possible. Ball, C and Price, T 1995). When taking a successful abdominal x-ray, it is important to focus on the patient in relation to the controlling factors. There is no advance preparation required. The radiographer should get the patients history as they may determine exposure factors or inidcate any varitations that may be needed. The patient lies in a supine position (facing upwards). The bladder and the symphysis pubis should be included on the radiograph. The patient should be straight and parallel to the table.

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  15. In relation to human cells

    (King, 2009). Osteoclasts can be known as the bone-removing cell. They are a large cell and have multiple nuclei. They occur in small hollows which erode into the surface. These hollows are called Howship's lacunae. The underlying lamellae are cut by these hollows. (King, 2009). These bones cells also have a unique function, which underlies the importance of each individual cell. Osteoblasts are the principle osteocytes (or bone cells) and their main function is bone remodelling. (Bontrager and Lampiano, 2010). They are bone building cells and lay down fibres, matrix and calcium.

    • Word count: 1982
  16. Macromolecule Analysis

    Amylose is an unbranched, helical molecule whose sugars are joined by ? (1 � 4) linkages. Amylopectin is a branched helical molecule. The amylose forms helices where iodine molecules assemble, forming a dark blue/black colour. The amylopectin forms much shorter helices and iodine molecules are unable to assemble, forming a brown/orange colour. (Karp 2010) Benedict's test is used to detect reducing sugars. Benedict's reagent is clear blue but when combined and heated to boiling with a substance containing glucose in a chain form, the cupric ions are reduced to a cuprous form (Cu+ )

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  17. Immunology Practical: Enzyme Linked Immunosorbent Assay (ELISA)

    They also called indirect ELISA or sandwich ELISA. Microtitre plates are coated with antigen. Samples is added and the bound antibody subsequently detected by addition of an enzyme-labelled antibody specific for the bound antibody. This enzyme labelled antibody is referred as the detector antibody. The detector antibody is not always labelled directly and a second enzyme- labelled antiglobulin antibody, directed against the detector antibody, is sometimes used. Method You first need to wash the plate with diluting buffer; removing the content of the plate (pre-coated antigen) in the sink first; spill the content vigorously (but do make sure that you don't splash the content out, should remain in the sink).

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  18. Agglutination & lysine of sheep red blood cells

    Aims & Objectives The main objective of this experiment was to observe what actually happens in the agglutination and lysis reactions, also to help us understand the processes more clearly, and to determine the agglutination and lysine titres, making me understand how differently immune and non-immune serum would react, to sheep red blood cell. The experiment gives understanding of the importance of agglutination in immunology. Method Firstly, the agglutination experiment with the immune rabbit serum was carried out. But before I started the experiment, I had to wear my lab coat, safety glasses and gloves prior dealing with any of the substances for precautious measures.

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  19. IMMUNOLOGY PRACTICAL: Differential Blood Cell Counts

    To perform a differential cell count, you must be able to identify the different types of white blood cells. The ability to properly identify the different types of white blood cells is not difficult to develop, but require a thorough knowledge of staining characteristics and morphology (the study of the form and structure of organisms). This knowledge can be gained only by extensive, supervised practice. METHOD For this practical you have to produce a blood smear of an infected animal, but due to not being able to handle blood containing parasites, you will be provided with a prepared blood smear slide.

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  20. In order to test our hypothesis which states that sequence identity shared among orthologous proteins is not different from the sequence identity shared among paralogous proteins, we used bioinformatic databases. We found that sequence identity

    1995). Molecular evolution has opened a whole new field of scientific research. The purpose of this paper is to examine the amount of relatedness found in proteins that are classified as homologs by testing whether sequence identity among orthologous proteins is different from the sequence identity among paralogous proteins. In order to test our hypothesis which states that the sequence identity shared by protein hormones that are paralogs is not different than the sequence identity share by protein hormones that are orthologs, we used bioinformatic databases to compare human prolactin, pig prolactin, human somatotropin (growth hormone), and fish prolactin.

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  21. s****l Dimorphism Displays in Genders of Uca longisignalis, h**o sapiens, and Poecilia latipinna

    This is called s****l dimorphism. The purpose of the report is to discuss whether s****l dimorphism in size exists in a range of animals. In order to test our hypothesis which states that the mass, standard length, and height in males did not differ from females, we used three species: Uca longisignalis (fiddler crab), Poecilia latipinna (sailfin mollie), and h**o sapiens (human) because of their prominent displays of s****l dimorphism. In order to discuss s****l dimorphism, we must first define it and gather some background information.

    • Word count: 1515
  22. Molecular Properties of Enzymes

    These macromolecules act as a biological catalyst and can expedite reactions without being used up in the process. They also possess the ability to lower the amount of energy the reactants need to absorb in order for a reaction to commence (Campbell et al 2008 pg 153). The reactant to which an enzyme acts on is called a substrate. Substrates bind to the region of an enzyme called an active site, which forms an enzyme-substrate complex. While the enzyme and substrate are joined together, a catalytic reaction occurs and converts the substrate to a product.

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  23. Biology Light & Life

    The photons reflect off the object 2. The photons are transmitted through the objects 3. The photons are absorbed by the object * To be used by an organism the photons must be absorbed. � Pigment - A molecule that can absorb photons of light. - pigments differ in the wavelengths of light they can absorb. - pigments can capture light because of their structure: they contain a region where carbon atoms are covalently bonded with alternation single and double bonds (a conjugated system). This results in the delocalization of electrons.

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    It seems that any attempts to define life are doomed to failure due to the simple fact that the transition from the complex organic molecules (which were existent between 1 and 2 billion years ago on earth) to primitive, living microorganisms was so gradual. The first cellular life did not simply appear, but instead the chemical evolution of life occurred in a series of increasingly complex stages. So at what point do we say something is alive? This issue is particularly contentious, and indeed blurry, in this day and age with the legalization of abortion up until 24 weeks.

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  25. Discuss how changes in control of the cell cycle contribute to cancer development Cancer is a multifarious disease, with a common feature that most tumours harbour one or more genetic mutations that allow them to advance outside their normal growth restr

    Populations of cells in complex organisms, such as humans, undergo replacement and turnover of their macromolecular compounds. This is known as cell renewal. Exceptional to this are cardiac muscle and many nerve cells, which are mitotically inactive, but even such differentiated cells replenish their molecules and structures under the influence of appropriate stimuli (Avers, 1986). At the core of cellular proliferation is the cell division cycle, the process by which a cell grows, replicates its DNA and then divides to produce two genetically identical daughter cells. This intricate process is divided into four sequential phases, as depicted by the diagram below (Figure 1:1).

    • Word count: 4720

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