4. Suppose you have two tube racks, each with three tubes. The following compound has already been placed in the assigned tube in both racks: one being examined. Tube 1: albumin X Tube 2: starch O Tube 3: water ) rack 1 rack 2 + biuret +benedict + heat a. In the first rack of tubes, you add biuret reagent to each tube. →Predict the color result that you would expect to see for each of the tubes in the rack. Explain your logic for why you think that is the color you would see in each of those tubes. b. In the second rack of tubes, you now add benedict reagent to each tube and then heat the tubes up. >Predict the color result that you would expect to see for each of the tubes in the rack. Explain your logic for why you think that is the color you would see in each of those tubes. 5. Explain why tuna tested negative for otomli Procedures Part I. Using a Light Compound Microscope As magnification increases, the field of view decreases. For this reason, it is easier to find a specimen under the lowest magnification; you are observing the largest field of view at the lowest power. Thus, when viewing a specimen, always start with the 4x objective lens and use the coarse adjustment knob to focus. Once the specimen is in focus, switch to the 10x objective and re-focus using the fine adjustment knob. Repeat this process with the 40x objective. Important: Using the coarse-adjustment knob while the 10x or 40x objective is in place may damage the objective lens! NEVER DO THIS 1. Obtain a compound light microscope from the cabinet. Always carry the microscope with one hand on the ARM and the other hand underneath, supporting the base. 2. Back at your bench, remove the cover. Take note of all the microscope's parts that you read about in the introduction. Practice identifying these features hands-on. **you get stuck with naming parts, remember that the introduction to this lab has an image of a compound light microscope that has labels added. 3. Unwind the cord. Plug in the microscope. The power button is located on the back of the microscope at the base. Observe brightness of light. The dimmer will change the intensity. 4. Using a CLEAN kimwipe or lens paper, wipe the eyepieces and the stage. 5. Tum the course adjustment knob toward you to lower the stage as low as possible. Using the revolving nose piece to rotate the objective lenses, position the scanning power lens (low power, 4x) in place. The lens will click into place when it is properly positioned pointing straight down at the stage. Focusing on a Specimen 6. Obtain a letter "e" slide. Clean the top ene rtionn surfaces of the slide. Any dust or fingerprints will limit clarity. Pinch the adjustable side holder and position the slide between the metal holders. Use the stage adjustment knobs (which hang down below the stage) to center the portion of slide that has the specimen on it over the light that is shining up through the stage. 7. Raise the stage as high as possible with the coarse adjustment knobs. Look through the eyepieces (ocular lenses) and adjust the width so that you see ONE image using both of your eyes. Lower the stage ½ turn and the image will come into focus. Use the coarse focus knob to sharpen up the image; use the fine focus knobs to get the image as sharp and clear as possible. Thought Questions: Look at the objective lens that you are currently using. What color is the band on the lens? had bund What is the magnification of this lens? 4 What is the TOTAL magnification when using this lens?40 33