Lab Work Not Included
The purpose for completing this lab was to observe how microscopes function. The invention & evolution of the microscope has been an ongoing process since the Middle Ages, when the first convex magnifying lenses were introduced. In 1590, the Jansen Brothers invented the first compound microscope (two or more lenses).However, Antony van Leevenwenhoek created the first “true” microscope, in 1665, with 300x magnification & unbelievable resolution. During the late 1700’s, the microscope was reinvented with 1500x magnification. The most recent advancement in microscopes is the electron microscope, which was invented in 1930. This particular model uses an electron beam, instead of light & 4,000,000x magnifications with
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These lenses are held by the revolving nosepiece. The stage is the platform where you place your slide. The details of the specimen on the slide can be enhanced by using the fine & coarse adjustment knobs, which make very small or large adjustments, respectively. During the lab, I learned & practiced the different effects of fine & coarse adjustment on the microscope. The compound microscope uses these two knobs to improve the clarity of the object(s) being studied. First, I used the coarse knob to focus on the specimen. The image was still small at this magnification, but without this step, I wouldn’t be able to find it on the higher powers. Once the image was focused, we switched to low power and refocused with the coarse knob. Next, we switched to high power and focused with the fine adjustment. Finally, we adjusted the diaphragm because the specimen was too dark. I also learned how to make a wet mount. The procedure of making the first wet mount was started by cutting a lowercase letter “e” from a piece of newspaper. Next, I used a medicine dropper to put a drop of water on the center of the slide. Then, I put the “e” on the drop of water. Finally, I lowered the cover slip at approximately at 45angle, so it would prevent the formation of air bubbles. Microscopes are an important learning tool when doing scientific experiments. Throughout the lab, I learned the history of the microscope and the
The purpose of this lab was to identify an unknown bacteria culture using differential tests. The identification of the unknown culture was accomplished by identifying the bacteria based on its specific metabolic characteristics and morphology. It is suggested that culture 11 is a sample of Enterobacter aerogenes.
Concept 6.1 Biologists use microscopes and the tools of biochemistry to study cells 1. The study of cells has been limited by their small size, and so they were not seen and described until 1665, when Robert Hooke first looked at dead cells from an oak tree. His contemporary, Anton van Leeuwenhoek, crafted lenses and with the improvements in optical aids, a new world was opened. Magnification and resolving power limit what can be seen. Explain the difference. Magnification is the ratio of an object’s image size to its real size. Resolution is a measure of the clarity of the image; it is the minimum distance two points can be separated and still be distinguished
Preparing specimen for electron microscope hard, light microscope still very useful as a window on living cells.
This experiment was performed to observe differences in density based on the chemical makeup of an object. Pennies minted before 1982, pennies minted after 1982, and an unknown metal sample was tested to see if there were any differences in their densities. Ten pennies from each category and the metal sample were weighed using a scale to find mass and the displacement method was used to find their volumes. The masses and volumes were then used to calculate the densities of the pennies (D=m/v). The density of the pre-1982 pennies were 8.6 g/mL while the post-1982 pennies were 6.9 g/mL. The metal sample’s density was 1.7 g/mL. Following the experiment we were given the real densities of each item to calculate the percent error with the formula
Paragraph 1 - How the Law of Conservation of Matter is supported by the experimental demonstrations: In the law of conservation particles and materials are neither created nor destroyed . It was similar towards the experimental demonstrations because nothing changed or destroyed in the processes .Kinetic and potential energy was used in the experiments.
The illuminating parts of a microscope enable us to see the detail of the subject placed under the microscope. The three main parts that enable us to do this are: the condenser which illuminates the object that is placed under the microscope, the objectives which forms the magnified image, and the eyepiece which enables us to see the magnified
As soon as the water was added a timer was set for two minutes and the slide was placed under the microscope.
As soon as the water was added a timer was set for two minutes and the slide was placed under the microscope.
In electron microscopy, on the other hand, a beam of electrons with a negative charge, instead of light is sent through a very thin slice of the specimen. Because the electron beam has a far smaller wavelength than light used in light microscopy, it achieves far better resolution, “the current resolution of limit of the best electron microscope is approximately 0.05 nm atomic resolution, and 4000X better magnification than that of a conventional light microscope”(BSP, S., 2010). This means that with an electron microscope you can potentially achieve enough magnification to observe the shape of the protein machinery that carries out the work inside of cells. The major limitation of electron microscopy is that specimen
Table 1 Concentration of protein, DNA, and ratio of the two in heart, kidney and liver of bos taurus. Average standard deviation of protein concentration is also shown.
By using their microscopes, they found that every living plant and animal they examined was made of cells. As microscopes were improved, scientists were able to see smaller and smaller organisms. They found that no matter how large or small the organism was, it was made of cells, leading to cell theory. For example, a German biologist, Theodor Schwann discovered that all plant and animal cells were divided into cells by looking through his microscope. He also discovered that the cell is the basic unit of organization in organisms. Cells can be grouped together to form tissues, which can in turn be grouped together to make an organ. Organs can be grouped together to form a system, which is part of an organism. He was able to use microscopes to see the ways that cells work and help to determine which kind of microorganisms (bacteria) is causing the disease and making people ill. This is particularly valuable in the study of the components of organisms, where physicians are able to overcome a treatment of method to kill disease cells and restore people¡¦s health. The microscope revealed not only the cellular structure of human tissues, but also the organisms that cause diseases. The discovery of cells led scientists to study cells and discover more information about cells; this, allowed scientists to find ways to prevent or cure diseases. The use of microscopes has made many
The materials used for the first part of the experiment comprised of the following: a microscope, 4 slides, 4 slide covers, blood samples, lancet, a sheet of paper towel, 3 test tube droppers, Solutions A, Solutions B, and Solution C.
Procedure: First, set up the microscope. Clean the ocular lenses and objectives with lens paper. Then pace the prepared e slide on the stage and make adjustments. Turn the rotating nosepiece until the 10x objective is above the ring of light coming through the slide. Move the slide using the X and Y stage knobs until the specimen is within the view. Adjust the focus by looking into the eyepiece and focusing the specimen with the coarse then fine focus knobs. Adjust diaphragm until there is sufficient light
NOTE: Answer Question A only if you used a compound light microscope for this experiment.
Most microscopes, including those in schools and laboratories today, are optical microscopes. They use glass lenses to enlarge, or magnify, an image. An optical microscope cannot produce an image of an object smaller than the length of the light wave in use. To see anything smaller than 2,000 angstroms (about 1/250,000 of an inch) a wave of shorter length would