Blood Buffer Essay Example for Free

Blood Buffer Essay Objectives: After completing this exercise and reading the corresponding material in your text, you should be able to 1. Prepare a wet mount slide 2. Identify structures described in this lab on slides 3. Cite examples of the wide diversity of cell types 4. Relate differences in structure among cells to functional differences Introduction Structurally and functionally, all living things share one common feature: all living organisms are composed of cells. The development of this concept began with Robert Hookes seventeenth-century observation that slices of cork were made up of small units he called cells. † Over the next 100 years, the cell theory emerged. It was formally (and independently) presented by Schleiden and Schwann in 1839, and clarified by Virchow a few years later. This theory has three principles: (1) All organisms are composed of one or more cells. (2) All life processes derive from the activities of cells. (3) All cells arise from preexisting cells. Living organisms are composed of one or many cells, and every activity that occurs in a living organism is ultimately related to metabolic processes in cells. Understanding the processes of life requires an understanding of the structure and function of the cell. Although cells vary in organization, size, and function, all share certain structural features. All are enclosed within a plasma membrane, defining the boundary of the living material. All contain a region of DNA (deoxyribonucleic acid), which forms the genetic code. Inside of the plasma membrane is watery cytoplasm, and the chemical processes inside the cell occur within this watery medium. Upon microscopic examination, we see there are two basic types of cells, prokaryotic and eukaryotic, see the table below to see a comparison of the two cell types. For these following exercise you should use the highest magnification possible, because you will be able to see more detail, and you should record your observations at this magnification. Always begin with the lower magnifications, once you have found your specimen center it and focus it before increasing the magnification. We will not be using the 100X objective because it requires special handling and immersion oil, so you should use the 40X objective for most observations. What is the total magnification of a sample view with the 40X objective? Remember there is a lens in the ocular that magnifies the image 10x, so the total magnification will be 40 x 10 = 400X. Exercise 1: Examining Prokaryotic cells 1. What types of organisms are prokaryotic? 2. What structures are found in a Eukaryotic cell that will not be visible in a Prokayotic cell? 3. Examine the specimens available at the back of the classroom. Locate a prokaryotic cell and bring it back to your microscope. Name of specimen: ____________________ 4. Examine your specimen under the microscope. Sketch your specimen under 40x magnification below. Be sure to label any internal or external structures visible. Exercise 2: Examining Eukaryotic cells The cells on which we focus most of our attention are relatively large and complex, although many details of their structure are only evident with electron microscopy. The word eukaryote derives from the visible nucleus found in most of these cells. No one cell will show all of the features that a cell might have, so you will be observing a variety of eukaryotic cells. Protist cells: The protist kingdom includes eukaryotic unicellular forms (e.g., protozoans, algae, slime molds) as well as some simple multicellular forms. Many are mobile; some are photosynthetic; others are animal-like, ingesting food particles, or fungi-like, secreting digestive chemicals into the environment. Protists are diverse, often having complex cells. 1. What structures do you expect to see in these cells that was not evident in the prokaryotes you saw? Cultures of mixed protists and/or pond water are available in lab. Many different forms may be found in these cultures, including amoebas, flagellates and ciliates. (Many classifications of protists are based on how they move – with flagella, or cilia, or neither of these.) 2. Examine the specimens available at the back of the classroom. Locate the cultures of protist cells. You will examine two separate cultures. One of the cultures you’ll examine is the â€Å"Mixed Pond Protists,† you can pick which specimen you’ll examine for your second sample from the other cultures present in class. Make a wet mount of each culture, drawing material from the debris at the bottom of the culture jar. Name of specimen #1: Mixed Pond Protists Name of specimen #2: ____________________ 3. Observe first with scanning power (4X objective), looking for movement. If you don’t see anything, wash the material back into the jar and get another drop. Once you have located organisms, observe on higher power (40X objective). If the protists are moving very rapidly, they may swim out of the field of view. In this case, remove the coverslip and add a small drop of Detain. Detain is a thick solution that will help slow down the protists. REMEMBER THAT THE MICROSCOPE LIGHT IS HOT. Turn it off when you are not looking at the slide. 4. Examine your specimen under the microscope. Sketch each specimen under 40x magnification below. Be sure to label any internal or external structures visible. 5. What evidence do you see that protists are eukaryotes? 6. Attempt to identify the protists you have observed. There are several keys to protists available. Your instructor can help you use the keys if you’re not familiar with how they work. Write the name of your protists and your rationale for identification based on the characteristics in the key into your notes. When you have finished looking at your slide, place the slide in the bleach water. Plant cells: Plant cells are different from animal cells in many ways. 1. Name three ways plant cells differ from animal cells below. As in animals, cells of plants are organized into tissues, aggregations of similar cells performing a common function in a multicellular organism. In this part of the lab, you will look at several types of plant cells. Onion epidermal cells: 1. Make a wet mount of a colorless scale of an onion bulb by peeling the thin, membranous layer from the inside of one of the bulb scales and placing it on a slide in a drop of water. This usually works best if you partially slice through a ring, allowing the thin layer of tissue on the inner surface of the leaf to be pulled off. Use forceps to arrange the tissue in a drop of Iodine on a slide and cover with a cover slip. 2. Observe your preparation with the microscope, focusing first with the scanning power objective. Continue your study, switching to the low power (10 X) and finally the high power objective (40 X). 3. What shape do most of these cells have? What structure maintains this shape? 4. What structure is stained by the iodine? 5. Examine your specimen under the microscope. Sketch each specimen under 40x magnification below. Be sure to label any internal or external structures visible. 6. Which cellular components present in most leaf cells are absent from onion leaf cells? Elodea leaf cells: 1. Remove a single young leaf and prepare a wet mount. Examine the leaf first on scanning power, then on low power. 2. Examine your specimen under the microscope. Sketch each specimen under 40x magnification below. Be sure to label any internal or external structures visible. 3. After the cells have warmed a bit from the light of the microscope, you may see cytoplasmic streaming. Microfilaments in the cytoplasm are thought to be responsible for this intracellular movement. What cellular structure do you see moving around the cytoplasm? Animal cells: Human epithelial (cheek) cells: 1. Using the broad end of a clean toothpick, gently scrape the inside of your cheek. Stir the scrapings into a drop of saline and a drop of Methylene Blue on a clean microscope slide and add a cover slip. Do not reuse your toothpick. DO NOT PUT IT BACK WITH THE CLEAN TOOTHPICKS AND DON’T LAY IT ON THE TABLE. Discard it in the BIOHAZARD bag. 2. Because the cells are almost transparent, decrease the amount of light entering the objective lens to increase the contrast. Find the cells using the low power objective of your microscope, then switch to the high power objective for detailed study. Find the nucleus of a cell. Many of the cells will be folded or wrinkled due to their thin, flexible nature. 3. Examine your specimen under the microscope. Sketch each specimen under 40x magnification below. Be sure to label any internal or external structures visible. 4. Dark specs on the cells are bacteria, similar to the E. coli you looked at earlier. How big are these bacterial cells relative to your cheek cells? Discard this slide into the bowl containing the bleach water. Sheep’s blood (wet mount): Blood consists of two parts a liquid portion (water + proteins) called plasma, and a cellular portion, containing many different cell types, including erythrocytes or red blood cells (RBCs), and leukocytes or white blood cells (WBCs). Red blood cells are red because they contain a lot of the oxygen-carrying molecule hemoglobin. The blood sample we have has been treated chemically to prevent clotting. 1. Prepare a wet mount by placing a drop of saline and a small drop of blood on the slide. Add a cover slip. Examine a portion of the slide in which the blood is diluted. 2. Examine your specimen under the microscope. Sketch each specimen under 40x magnification below. Be sure to label any internal or external structures visible. 3. What is missing from these cells that is found in eukaryotic cells? 4. How do the red blood cells compare to your cheek cells in size? What shapes are the cells? Discard this slide into the bowl containing the bleach water. Cells Review Questions Your answers should be specific and to the level of the lecture, book and lab manual. You may need to use outside sources. 1. What characteristics do all cells have in common? 2. What characteristics are common to all eukaryotic cells but not found in prokaryotic cells? 3. Would you expect that all the living cells you saw in lab contain mitochondria? Explain. 4. Did all living plant cells you observed contain chloroplasts? Explain. 5. Describe as many differences as you can between plant and animal cells at a cellular level. Do any of these differences relate to the organismic differences we see between plants and animals? Explain. 6. How do prokaryotic and eukaryotic cells compare in size? 7. How would you compare a protist cell to a cell from your body, a cheek cell for example, in terms of complexity at the cellular level?

The Glass Menagerie Essay -- Essays Papers

The Glass Menagerie Symbolism is a major aspect in Tennessee William's famous play, "The Glass Menagerie." On the surface, the short slice of life story seems to be simple. However, if the reader digs deeper they will find that there are several symbols that give the play a deeper meaning. Each character defines each symbol in a different way. There are some very noticeable symbols that can be analyzed when studying "The Glass Menagerie." The first is the actual glass menagerie that represents the fragility of the Wingfield's dreamlike existence. The second is the fire escape, which reflects each character's tendency to escape from reality in their own ways. The third is the yellow dress, which represents youth and the past. The actual animal collection, or glass menagerie, symbolizes each character in the story. Like the glass animals, the characters' realities are very fragile and in danger of being shattered. It is also as though the characters are stuck in glass, unable to move or change, also like the glass animals. They are inanimate, as the characters have learned to be to hide and escape from the pain that life has given them. Laura loves the glass animals because her family is like them. It will not take much, like Tom leaving, to shatter their whole world. Laura is symbolized by her fragile collection of glass animals, the glass menagerie. Her favorite animal is the unique unicorn. The unicorn is different because it has a horn. When Lau...

Business: Eating and Finagle A Bagel Essay

1. How has the business cycle affected Finagle A Bagel? * The business cycle has affected the Finagle A Bagel in a positive way. I say this because the business is spreading and opening up more restaurants, so the business cycle has had a successful impact on the business even though running the business is nonstop. 2. What is Finagle A Bagel doing to differentiate itself from competitors that want a share of consumers’ dining dollars? * The Finagle A Bagel restaurant uses high quality, fresh products, courteous and competent employees, clean, attractive and inviting restaurants to differentiate themselves from competitors. 3. Why would Finagle A Bagel donate bagels to local charities rather than give them away to customers or employees? * The Finagle A Bagel would donate bagels to local charities due to the fact of it raising awareness of the businesses name in the community and surrounding areas. By doing this, it will increase peoples interests to eat at the restaurant due to the good they served in the community. 4. If you wanted to open a bagel restaurant in Hong Kong, would you license the Finagle A Bagel brand? Why or why not? * Yes, I would open a business in Hong Kong and license the Finagle A Bagel brand. I would do this because it is a very popular business that has a good name out for them. It would be a great opportunity to spread the greatness of this business. If I opened a business in Hong Kong and licensed the Finagle A bagel brand, it would bring many opportunities into the area such as donated unused bagels in this area of the world.

Is Cancer A Bottle - 1358 Words

Cancer in a Bottle Carcinogens, which are cancer-causing substances, are found in incredibly startling amounts of consumer products that people use every day, including beauty or body care products such as shampoo and cosmetics. The carcinogens and other ingredients present in consumer products have been linked to many different kinds of cancers, endocrine disruption, developmental and reproductive toxicity, bioaccumulation, ecotoxicity, and changes in molecular structures, yet they are legally allowed to be in the goods people use daily. In order to curb the presence of cancer-causing ingredients in consumer products, it’s necessary to notify consumers of the existence of carcinogens in products through warning labels, to educate†¦show more content†¦Dove brand’s â€Å"Oxygen Moisture Shampoo†, at an unbeatable price of $3.99, contains four ingredients linked with ecotoxicity and cancer – Sodium Laureth Sulfate (can be contaminated with 1,4-dioxa ne, which is known to cause cancer), Parfum (some types are linked to triggering asthma, allergies, causing cancer and neurotoxicity, and can be harmful to the environment and wildlife), Mineral Oil (derived from crude oil and is a known human carcinogen), and Tetrasodium EDTA (causes organ system toxicity) (Unilever) (David Suzuki Foundation). Nowhere on the packaging of the product does it mention a single word of caution about the ingredients present in the shampoo, but it does proudly display an award it won from 2011. Although the price of $3.99 is unbeatable for consumers looking for some cheap shampoo, consumers need to realize the impact these ingredients can have on their bodies and the environment – a cheap shampoo in the present could have a severe impact in the future, and those $3.99 bottles of shampoo could turn into $10,000 a month for cancer treatment or higher taxes to attempt cleaning up the environment of the toxins these products leave behind (Nicastro). T o encourage people to find alternatives to products that contain carcinogens, warning labels should be placed on the packaging of these products. Having any kind of information about potentially harmful ingredients would be beneficial to consumers, be it with warning labels akin to