...Introduction: The microbiology of food and the environment are two very important fields in the large scope of microbiological research. Because microorganisms exist almost everywhere, it is important to determine the influences that they place on the food we depend on for survival, and the environment in which we humans call home. In this lab, we conducted five experiments in these two fields, and in doing so gained a better understanding of the influences and importance of microbes in food and the environment. The first exercise was the enumeration of soil microbes. This experiment showcased the immense diversity of bacteria, actinomycetes, and fungi found in soil. This diversity ranges from microbes that are beneficial to the environment by decomposing dead organic matter into energy sources usable by other organisms, to the pathogenic bacterial and fungal spores that can infect humans and animals alike. The techniques used are serial dilutions, which allow for quantification and a close estimation of the amount of said organisms found in a soil sample. (1) The second exercise that we conducted was the microbiology of water experiment. This is a very important standardized experiment used to determine the density of coliforms found in a 100 mL sample of water. It also can be used more specifically to determine the density of Escherichia coli, which can cause food poisoning amongst other illnesses. The techniques used are the multiple tube fermentation method, which involves...
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...Lab Report Cells as a Source of Energy Answer the following questions about the results of this activity. Record your answers in the boxes. Send your completed lab report to your instructor. Don’t forget to save your lab report to your computer! Activity 1 Record your data from Activity 1 in the boxes below. Enter the samples you added for each trial (methylene blue, glucose, etc…) in the “Variable Added to the Cell Culture” column and the corresponding electrical output results in the “Millivolts Produced” column. | | | | |Trial |Variable Added to the Cell Culture Chamber |Millivolts Produced | |1 |None | | | | |0 | |2 |Flavin Mononucleotide Without light |5 | |3 |Flavin Mononucleotide With light |50 | |4 |Sodium Bicarbonate With light |65 ...
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...to know the characteristics of diffusion and to formulate hypothesis based on diffusion. It has also a purpose to see whether the diffusion is dependent on distance, rate and molecular weight of the substance. The estimation of distance is predicted by getting the average of the substance. Rate is predicted by subtracting the final diameter to initial diameter and dividing it by time. It is determined that there are three things which influence the movement of molecules such as kinetic energy, nature of the environment and size of the molecules. By this, we know which dye diffused at the fastest rate by measuring the diameter of the colored area immediately after adding the substance to the agar plate. After one hour of measuring the methylene blue by 15 minutes interval, the substance moved immediately in 0min until 45minutes, the remaining minutes remains the same. While on the potassium permanganate, the substance moved from 0minutes to 1hour. These happened because they had different molecular weight and also the size of the substance that we put on the agar plate. It is expected that once a substance place into an agar plate it will move immediately because of the presence of the jelly in an agar. INTRODUCTION 1.Diffusion is a process of equalization which involves movement of molecules from an area of high concentration to an area of low concentration. These molecules are in a constant state of motion and they are...
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...**IF YOU ARE USING THIS** please note that this was an experiment conducted by me and my lab partner. Due to the fact that she wrote the materials/methods section and the abstract, I have not included it. This is only results and analysis for a diffusion lab for a Biology400 college class. Please do not copy and paste, it is PLAGIARISM. Only use for clarification of analyzed results. Results Figure 1a. The following table includes the circumference of the circle that was created by the diffusion of three separate dyes. It also includes their molecular weight. The chart shows that Potassium Chromate diffused much more than the Methylene Blue and the Congo Red, both in the refrigerated gelatin and the room temperature gelatin. The Methylene Blue has the second lowest molecular weight, and diffused more than the Congo Red as well. The results also show that, with the exception of the Potassium Chromate, the dyes in the refrigerated gelatin diffused at a slower rate than those in the room temperature gelatin. Solute (Dye) Molecular Weight Room Temperature Distance (mm) Refrigeration Distance (mm) Potassium Chromate 194 18 19 Methylene Blue 374 15 10 Congo Red 697 12 11 Figure 1b. The image below is a photo of the gelatin plates an hour after they were dyed. The plate on the left was placed in the refrigerator, while the plate on the right remained at room temperature. Figure 2. The table below illustrates the rate of osmosis for each of four different combinations...
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...LAB6_AEROBIC AND ANAEROBIC GROWTH As humans, we are accustomed to thinking that oxygen is essential to life. Microorganisms, however, are quite adaptable and diverse and vary considerably in their oxygen requirements. Some bacteria require oxygen; some can grow with or without it and some are actually killed by oxygen. Bacteria are generally classified into three main groups with respect to oxygen: 1. Obligate aerobes: Like humans, these organisms have an absolute requirement for oxygen. Because aerobic metabolism generates the toxic byproduct hydrogen peroxide, obligate aerobes must produce the enzyme catalase which breaks down hydrogen peroxide to water and oxygen gas. 2. Obligate anaerobes: Not only do these organisms not require oxygen, they are often killed in its presence. Because anaerobic metabolism does not generate hydrogen peroxide, obligate anaerobes generally do not produce catalase. The causative agent of botulism, Clostridium botulinum is an obligate anaerobe. Since the canning process removes the air, Clostridium botulinum can grow in inadequately sterilized canned foods. This isn't normally a problem in fresh foods since they are exposed to air. 3. Facultative anaerobes: These organisms will use oxygen in their metabolism if it is available, but can also grow without oxygen. Again, since aerobic metabolism generates hydrogen peroxide, they produce catalase. E. coli, which is normal flora of the intestine, is an example of a facultative...
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...A gram (+) bacteria will be blue while a gram (-) bacteria will be red. A blue clustered bacteria was seen in the microscope. It was then inferred that the unknown was either Staphylococcus epidermis or Staphylococcus aureus. Figure 1 shows an example of how the unknown bacteria looked when observed with the microscope. Table 2 shows the expected results of staphylococcus epidermis and staphylococcus aureus. The information for this table was gained from the Bergey’s Manual, ncni.nlm.nih.gov and the microbiology lab manual. Most of the tests done produced similar results. Notable difference between these two can be seen on the Mannitol Salt plate and in the gelatin test. The unknown was able to ferment glucose and sucrose while lactose was unable to be fermented. The starch plate and EMB were negative. while the Mannitol salt plate turned yellow where the unknown was applied. The catalase test was a weak positive. The SIM tube was hydrogen sulfide negative and not motile, while the methyl red test was positive. The Voges-Proskaur...
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...Cell Membrane Transport Harjot Dhesi Zoology 2011-13 Amon Gekombe 17 February 2014 Introduction The human body must maintain a balance within itself in order to abstain from disturbances caused by the external environment, for example a sudden increase in the outside temperature, or even the internal environment of the body, such as a dramatic drop in blood pressure. The body maintains this equilibrium through various methods and regulators, beginning in the cellular level. The human cell has a selectively permeable plasma membrane, allowing only certain substances to easily pass through to reach the inside or outside of the cell. Small, uncharged, and nonpolar molecules pass with the most ease through the plasma membrane (Tortora and Derrickson 2012). The constant moving in and out of substances is crucial in sustaining the life of the cell. Tortora and Derrickson explain in their book Principles of Anatomy and Physiology that, “Certain substances must move into the cell to support metabolic reactions. Other substances that have been produced by the cell for export or as cellular waste products must move out of the cell” (Tortora Derrickson 2012). Because of the selectively permeable nature of its plasma membrane, the cell can retain chemicals that have a difference in concentration on the inside than on outside of the cell. This is called the concentration gradient. A substance can either move against its concentration gradient by an active process, which requires...
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...1) The experiment worked because when the plant cells and the human cells were viewed in the microscope, they took on differentiating forms, enabling visual differentiation of the two forms of cells. The onion skin cell, an example of a plant cell, generally has a rigid, rectangular shape. The onion skin cells were positioned beside each other (length touching length, width touching width) and formed a checkered pattern. When observing the onion skin cell, we noticed that the cells took on a brick-like structure and within the cells, small dots (the nuclei) can be seen.When we first looked into the microscope, the microscope’s total magnification was 10X so there were about a hundred rows of rectangular cells (see diagram provided), but as we changed magnifications, the number of cells in the field of view decreased.When we viewed the onion skin cells at 40X total magnification, we noticed the nuclei of the cells looked clearer and larger and we were able to study the cell with more understanding than when we used the first magnification. The organelles that we were able to see in this type of cell were the nucleus, the cytoplasm and the cell wall. | -----The cheek cell, an example of an animal cell, generally has a circular, oval shape. the animal cell structure is the most prominent in human cheek cells. animal cell simply stands on it's own without being closely packed together. We noticed that the cells were secluded and spread out (see diagram provided), when we viewed...
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...Discussion: The purpose of this experiment is to identify an unknown organism over three weeks by performing lab exercises that were previously performed. The unknown #16 was chosen for this experiment. During the first week, The next step in determining this unknown was to perform the streak plate method for isolation of colonies of a 24-hour period in a 37o C incubator. The unknown organism grew on the media; observed white in color, raised with a smooth margin, shiny colonies on the TSA agar plate. The next step in identifying this unknown #16 was to steak for isolation on plated media; then incubated at 37o C for 24 hours and the stores at 4o C. The plates used for isolation were; Triple Salt Agar (TSA), Mannitol Salt Agar (MSA), Phenyl...
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...Systematic Methodology used in the Identification and Isolation of Escherichia coli and Bacillus cereus from an Unknown Culture. By: Richard Martinez MCB-2010L Microbiology Lab Dr. James Rogers 11/29/13 Unknown bacteria were determined to be Escherichia coli and Bacillus cereus due to their morphological, physiological and metabolic properties. I. Abstract In a laboratory setting, it often becomes necessary to identify an unknown organism. In this experiment, researchers classified some unidentified bacteria based on their physical structure, colony morphology, optimal conditions and metabolic properties. A Gram stain using crystal violet, iodine, and safranin and a simple stain using methylene blue characterized the organism’s cell walls. Cultural behaviors were classified by inoculating the organisms onto nutrient agar and incubating them at 30° and 37° C for 48 hours, and observing their behaviors, as well as using Mannitol and phenol red media for fermentation and acid production. Optimal growth temperatures were determined by incubating nutrient agar plates of the organisms at 30° C and 37° C. The metabolic profile was created by inoculating the bacterium into broths containing lactose, mannitol, and citrate and incubating the tubes at 30° and 37° C for 48 hours, then observing them for color change. The stains revealed that the bacteria were both Gram-negative and Gram-positive bacilli. Organism “A” was shown to not grow on MacConkey agar and to have...
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...MLT1 – Lab Report 1 Bacterial Morphology Nichole Performed at Home 3/21/13 Bacterial Morphology A. Comparing Observations from Mounting Techniques Four mounting techniques were used during this experiment which included the fresh wet mount, direct staining using crystal violet, and indirect staining using both Congo Red and crystal violet. There was a liquid appearance in the wet mount slides with the cells appearing very similar in color to the liquid from the sample. The cells and their borders in the wet mounts were not as distinct in appearance as in the staining methods. While the bacteria shapes were able to be identified in the yeast wet mount, it was very difficult to determine the shapes in the cheek smear. The next method used was the direct staining using crystal violet. The cells in the direct stained slides were very easy to view, well defined and were a distinct violet color. The indirect staining method using the Congo Red dye appeared to actually stain the cells in the cheek smear rather than the background and area around the cell. In the higher resolution cheek cell slide, the cell was outlined with the Congo Red dye. The yeast cells were easily identified using the indirect method however the cells in the plaque smear were not. There was a large area of dye in one area on the slide...
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...contaminants. A reserve stock culture should be made and after incubation and comparison with the original slant, kept with the original slant in the refrigerator. It is critically important that aseptic techniques are used during transfers and inoculations to prevent contamination of your cultures. If contamination is suspected, you will be able to fall back to your reserve stock. If you fail to maintain a reserve stock you will not be able to recover your organism if disaster strikes. The instructor will not provide a new culture for you to start with in the middle of the unknown exercises. It is your responsibility to: keep your organisms alive and fresh to run tests check with us if you question purity of your organism or your test results appropriately select media to identifying unknowns ask for...
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...Nursing Lab Values Cheat Sheet permalink ________________________________________ Lab Values: Cheat Sheet Red Blood Cells (RBC): - Normal: male = 4.6- 6.2 female = 4.2- 5.2 - Actual count of red corpuscles Hemoglobin: - Normal: male = 14-18 g/dl female = 12-16 g/dl - A direct measure of oxygen carrying capacity of the blood Hematocrit : - Normal: males = 39- 49% female = 35- 45% - = the percentage of blood that is composed of erythrocytes Mean Cell Volume (MCV): - Normal: male = 80- 96 female = 82- 98 - Mean Cell Hemoglobin (MCH): - Normal: 27- 33 - = % volume of hemoglobin per RBC * Increase: indicates folate deficiency * Decrease: indicates iron deficiency Mean Cell Hemoglobin Concentration): - Normal: 31- 35 Reticulocyte Count: - Normal: 0.5-2.5% of RBC - An indirect measure of RBC production Red Blood Cell Distribution Width (RDW): - Normal: 11-16% - Indicates variation in red cell volume * Increase: indicates iron deficiency anemia or mixed anemia - Note: increase in RDW occurs earlier than decrease in MCV therefore RDW is used for early detection of iron deficiency anemia Platelet Count: - Normal: 140,000 - 440,000 * Low: worry patient will bleed * High: not clinically significant White Blood Cell (WBC): - Normal: 3.4 – 10 * Increase: occur during infections and physiologic stress * Decreases: marrow suppression and chemotherapy Sodium (Na): - Normal: 136- 145 - Major contributory to cell osmolality...
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...UTAR FHSC1214 Fundamentals of Cell Biology Trimester 1 How YOU can do well in BIOLOGY Follow the 4A’s and you can expect A’s. A ttitude • Attend ALL lectures, tutorials and practicals on time without fail. • Be attentive in class and revise your notes after class while the topic is still fresh in your mind. Why waste time re-reading 2-3 months later? • Do your assignments faithfully as they carry marks for the finals. • Come prepared for lessons (i.e. read up beforehand). • Read up beforehand before attending lectures so that you won’t be lost and wasted hours of your life week after week. • Why stress yourself out if you can avoid it? Do NOT count on last minute revision for tests and examinations, as it will be too late to catch up and seek help in areas where you may find confusing or unclear of. • Why panic before exams because you can’t find this or that? Keep separate files for lecture, tutorial and practical. File up the respective notes systematically so that you do not lose them along the semester. • Do you expect the lecturer/ tutor to be available all the time to answer your questions? It is YOUR responsibility to take the initiative to clear your doubts or satisfy your curiosity to understand certain scientific phenomena by reading up on the relevant topics. A Based on a true story… A professor at the National University of Singapore recounts how on one occasion a student consulted him days before the exam. Student:...
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...Biology 100 – K. Marr (Revised Spring 2010) Lab 2. Microscopic Observation of Cells Prelab Assignment 1. Before coming to lab, read carefully the introduction and procedures of each part of the experiment. If you and your group members are not familiar with the procedure before coming to lab, you may have difficulty completing this exercise during the lab period. 2. Answer the Prelab Questions on the first three pages of the report sheet and be prepared to hand them in at the start of your lab class. Please be aware that you need to go online to answer prelab question #3. Goals of this Lab Exercise After completing this lab exercise you should be able to..... 1. Identify the parts of a compound light microscope and use a microscope to competently examine biological samples 2. Determine the diameter of the field of view for the various objectives of a microscope 3. Accurately sketch, describe and cite the major functions of the structures and organelles of the cells examined in this lab exercise 4. Estimate the size of specimens viewed with a microscope. The Microscope The microscope is one of the principal tools of the biologist. Without the microscope, many of the great discoveries of biology would never have been made. The light compound microscope, illustrated in Figure 1, is the type of microscope most commonly used. Proper, comfortable use of the instrument demands practice. The practice afforded you in this exercise depends upon familiarity with the parts of the microscope...
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