Microscope observation of animal and plant cells
Microscope observation of animal and plant cells Introduction Cells represent the make up of our being as well as many other organisms whether they are unicellular or multicultural. Cells can also be complex or quite simplistic in design and contents, depending on the purpose of its function in an organism. Typically when studying cells some form of magnifications must be used to see the finest details of the cell, microscopes are used due to constraints in human eyes that only allow us to see to so much. In essence their use is to see what the eye cannot. This may include processes such as mitosis, phagotycosis and other forms of transport within the cell. Even though microscopes aid in viewing cellular content what can be seen my be limited due to the sizes of the actual organelles, or the types of stains used to highlight organelles within the cell. For example mitochondria cannot be seen with a standard lab light microscope. When scientist want to view the contents of a cell there are 2 main types of microscopes they use Light and Electron. All depending on the budget they have and the detail needed will determine which they would use. In this experiment we will make use of the light microscope. Method As per schedule until the cell is stained with Eosin, which instead of 2 minutes it was left for 20 seconds. Apart from this alteration the method is as per schedule
Experiment (polygenic traits), fingerprint patterns will be examined
Introduction In this experiment (polygenic traits), fingerprint patterns will be examined. Using the fingerprint total ridge count (TRC) from the population of male and female students in the biology class you will explore how the traits of TRC illustrate the polygenic inheritance model. The polygenic inheritance model describes the nature of fingerprint ridge patterns. Fingerprint ridge patterns result from environmental influences on the expression of a number of interacting genes. At least seven genes are thought to be involved in finger ridge formation (Penrose, 1969). There are three main types of fingerprint patterns: arches, loops (ulnar/radial), and whorls. It is founded that the average TRC of all ten fingers for males is 145, and for females is 126. Looking at the general population, the fingerprint ridge patterns tend to be: arch, 5.0%; radial loop 5.4%; ulnar loop, 63.5%; and whorl, 26.1%. (Also see, (Bio molecules, cells and genetics, unit handbook: 61BL0020), Polygenic traits: fingerprint ridge count Page: 20-22). Materials and Procedure (See, (Bio molecules, cells and genetics, unit handbook: 61BL0020), Polygenic traits: fingerprint ridge count Page: 22-23). Results Table of class results No. Of students Loops Whorls Arches Total Ridge count Gender Radial Ulnar (TRC)
Identification of reporter genes
Introduction Reporter genes are genes with particular characteristics that make them easily identifiable when they are expressed by the organisms to which they are attached. They are used to determine if a gene of interest has been expressed within a cell. As a result of which they have become an invaluable tool in research for the areas of biochemistry, molecular biology, biomedical and pharmaceutical sciences. In the case of this paper the following reporter genes were used to identify the following organisms: Bacterial Organism Reporter Gene P.putida LuxA-E genes P.fluorescens LuxA and B genes P.aureofaciens XylE gene E.coli lacZY In order to introduce the reporter gene into an organism, the reporter gene and the gene of interest are inserted into a circular DNA strand known as a plasmid (vector). Here we used the following plasmids; pUCD607, pUC18 and the suicide vectors FAC510 and pUT-miniTn5/xylE so called because they cannot survive once integrated with the bacterial cell thus the bacterium require a growth medium to survive. To show that the gene of interest has been taken in, it is important that the characteristics of the reporter gene isn't expressed beforehand, in other words, in the case of this paper, the reporter gene can only be expressed under certain conditions after plating and incubation. The following table shows what characteristics are
Macromolecules in Food
Experiment 7: Title: Macromolecules in Food Objectives: * Detect the presence of carbohydrates, starch, proteins and lipids in food samples provided. * Carry out the tests that are used to detect the macromolecules found in the food samples. * Put into good use the methods that have already been learnt to test samples. Introduction: Everyday materials such as foods are composed of organic molecules such as carbohydrates, starch, proteins and lipids. It will be possible for us to determine if these organic substances are present by using the tests we learned in the last experiment. Various chemicals will be used in this practical to test for the presence of these molecules. Most often, we will be looking for a particular color change. If the change is observed, the test is said to be positive because it indicates that a particular molecule is present. If the color change is not observed, the test is said to be negative because it indicates that a particular molecule is not present. In all of the procedures, we will need to include distilled water as a control. Usually, a control goes through all the steps of the experiment but lacks one essential factor (the experimental variable). The missing factor allows you to observe the difference between a positive result and a negative result. If the control sample tests positive, we know that our test is fail. All of the
site directed mutagenesis
SITE-DIRECTED MUTAGENESIS ON DOUBLE STRANDED DNA Advances in molecular biology and DNA synthesis techniques have accelerated progress in the study of protein and its function. In the past, it had been accomplished either by chemically modifying individual amino acids or by inducing mutations in the gene coding for the protein under study1. However, there were problems in that chemical modification of a protein is not specific and several amino acids may be altered1. It was not always possible to produce the proper mutation in the desired gene function1. Later, these difficulties have been overcome with the technique called site-directed mutagenesis. Such technique was first developed in the mid 1980's. It is a widely used technique for introducing mutations into a particular DNA sequence, often with the goal of creating a point mutation in the corresponding amino acid sequence but leaving the overall sequence undisturbed2. Such a technique uses synthetic oligonucleotides and the whole process, in summary, is shown in fig 1. Fig 1: Summary of an Oligonucleotide directed site-directed mutagenesis1. The DNA carries a gene of interest and is purified and annealed to a synthetic oligonucleotide that contains the desired change in sequence, Here, an A:T base pair is converted to a G:C base pair. An oligonucleotide of about 20 residues that contains the required
The Effect of pH on the Rate of Catalase
The Effect of pH on the Rate of Catalase Analysis Catalase is an enzyme. All enzymes are proteins, made up of a string of chemically bonded amino acids which each contain variable -R groups that give them different properties. The theory that explains catalysation is known as the 'lock & key' theory. This states that the enzyme has an area on it, which is a specific shape that compliments the structure of the substrate; this is known as the active site. The substrate bonds with the active site and forms an enzyme-substrate complex, the bonds are strained and the ES complex splits releasing the new products. The pH of solutions is a measure of the concentration of H+ ions in the solution. For each integer the pH falls by the number of H+ ions grows ten fold. These hydrogen ions interact with the bonds of the protein. pH can have an effect of the state of ionisation of acidic or basic amino acids. Acidic amino acids have carboxyl functional groups in their side chains. Basic amino acids have amine functional groups in their side chains. If the state of ionisation of amino acids in a protein is altered then the ionic bonds that help to determine the 3-D shape of the protein can be altered. This can lead an enzyme becoming inactive. This is known as denaturing. When an enzyme is denatured the tertiary structure is altered, this affects the structure of the active site. If
A review of positive and negative impacts of microbes on the environment
A REVIEW OF POSITIVE AND NEGATIVE IMPACTS OF MICROBES IN THE ENVIRONMENT . INTRODUCTION .1. Microbes in the environment 'Microbiology is the study of microorganisms, a large and diverse group of microscopic organisms that exist as single cells or cell clusters; it also includes viruses which are microscopic but not cellular', (Madigan, Martinko and Parker, 2003: 1). It consists of prokaryotic organisms such as bacteria and archaebacteria; and eukaryotic organisms such as fungi, protozoa and algae. Microbiologists have evidence that microbes are the oldest life forms on earth. 'Isotopic ratios and microfossils indicate that chemical evolution led to primitive forms of prokaryotic life less than 1 billion years after the formation of Planet Earth, which is 4.5 billion years old', (Atlas and Bartha, 1998: 27). Figure 1.1 shows the evolutionary events of microorganisms over the last 4 billion years. Figure 1.1: Evolutionary events of Microorganisms (Source: Atlas and Bartha, 1997: 28) The human race, and many other higher life forms, owes its existence to microbial activity 10,000 years ago when cyanobacteria fixed oxygen in the atmosphere. Figure 1.1 highlights how biodiversity has gradually increased since anaerobic bacteria evolved. Scientific evidence shows that the sun's temperature has increased by 30% during the past 4-5 billion years. By microbial activity
Microbial Evaluation of Two Food samples (Chicken and Doubles) Aim: To identify and count different bacteria present in chicken and doubles (Salmonella, Staphylococcus, E. coli, and total aerobic bacteria).
Laboratory Exercise # 1 Title: Microbial Evaluation of Two Food samples (Chicken and Doubles) Aim: To identify and count different bacteria present in chicken and doubles (Salmonella, Staphylococcus, E. coli, and total aerobic bacteria). Objectives: * To understand the preparation of media cultures * To identify and enumerate the growth of bacteria on different media * To identify the bacteria present in chicken and doubles Introduction The microbial evaluation of foods usually require that individually viable propagules are encouraged to multiply in liquid media or on the surface, or within the matrix, of a medium solidify with agar (Adams and Moss 2000). Different group of microorganisms will grow best on selected media. However the general purpose of a media is to provide the necessary nutrients needed for the growth of the organism(s) under study. Two common methods used to culture microorganisms are: (a) pour plate and (b) spread plate. In the pour plate method, a sample (usually 1ml), is pipette directly into a sterile petri dish and mixed with an appropriate volume of molten agar. The medium is then allowed to solidify and then incubated. Colonies to be counted will subsequently develop embedded in the agar. In the spread plate method, a sterilized wire is usually dipped in the suitable diluted suspension of organisms and then used to streak the surface of
Survival rates of micro-organisms
Abstract Five bacteria have been incubated at certain temperature levels and the amount of growth observed in each case was recorded. In a separate instance, the bacteria were also exposed to high temperatures for set periods of time and then incubated. This exposure to high temperatures allows an observation of the effect of heat on the survival of the bacteria. These observations will help us to classify the five bacteria as Psychrophiles, Mesophiles or Thermophiles and understand why this is so. Introduction Bacillus stearothermophilus is a species of gram-positive bacteria found in soil, hot springs, arctic waters, ocean sediments and spoiled food products (www1). Bacillus subtilis is a Gram-positive, rod-shaped, nonpathogenic bacterium which lives in soil (www1) Pseudomonas fluorescens encompasses a group of common, nonpathogenic saprophytes that colonize soil, water and plant surface environments. As its name implies, it produces a soluble, greenish fluorescent pigment, particularly under conditions of low iron availability (www2). Escherichia coli are normally found in the small intestine of mammals and can cause humans to suffer from food poisoning. Enterococcus faecalis also known as Group D Streptococcus (cocci) is a Gram-positive commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals (Ryan KJ, Ray CG, 2004). As is evident
Compare & Contrast the recognition of Antigens by B & T Lymphocytes
Compare & Contrast the recognition of Antigens by B & T Lymphocytes The recognition of antigens varies amongst cells, as all cells are different in many ways, one of them would be how they work. There are two types, which are B and T lymphocytes, these 2 in many ways are the same in the way they recognize antigens, however, are different to each other dramatically. Antigens are able to generate antibodies. Antigens are mostly a protein or a polysaccharide. There are 3 types of antigens, these would be exogenous, endogenous and auto antigens. Exogenous are antibodies that have entered the body from outside, for instance when we inhale, endogenous is when the antigens have been a product from a cell and lastly autogenous antigens are only produced if the patient is suffering from disease however this type of antigen is not the target of the human immune system. B cell lymphocytes are able to make antibodies, also are able to detect and recognize and also respond to antigens. B Lymphocytes, secrete antibodies which help detect infection in the human body. We can easily tell if we have B lymphocyte cells, if your body didn't contain B cells, then you would get ill very quickly since your body could not detect infections. B Cell Lymphocytes originate on the bone marrow, which then migrate to the secondary lymphoid tissue. The role of B cells in the Human body is the response to