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Revised Spring 2021 BIO-110 LAB: OBSERVING FERMENTATION This lab assignment will require 10 days from start to finish without interruption

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Revised Spring 2021 BIO-110 LAB: OBSERVING FERMENTATION This lab assignment will require 10 days from start to finish without interruption. Read the entire lab assignment before you begin. Submission Instructions Type your answers and paste any required pictures directly into this Word document. Submit it via the Blackboard submission link in Word format (docx). • Answers typed into a new blank document or submitted in the other formats will not be accepted. • If this lab requires pictures, they must be embedded (pasted into the document) and will not be accepted as stand-alone files. Each picture must be sized to at least 3” x 3”. • Assignments may not be submitted via email without express permission from the instructor. If an assignment is submitted incorrectly, you will be contacted via email and the assignment will not be graded unless resubmitted properly. Late penalties may apply; lab assignments may be submitted up to 7 days late. Introduction All organisms need energy to live. Cellular respiration is the process that cells use to convert the energy from food into the more usable energy of ATP. If oxygen is available, a cell’s mitochondria can perform their “energy generator” job and make a lot of ATP energy through the electron transport chain. This version of respiration is aerobic respiration and it produces enough ATP energy to support large active, multicellular animals – like you. If oxygen is not available, large organisms cannot produce enough energy (ATP) to survive; this is why we die if we cannot breathe. However, some one-celled organisms can still digest sugars and make enough ATP energy to live and grow without oxygen. This version of respiration is anaerobic respiration. Anaerobic means “without oxygen”. When used by bacteria and fungi, anaerobic respiration is referred to as fermentation. There are two types of fermentation: 1) Lactic acid fermentation is used by bacteria (it’s how we make yogurt) and also occurs in muscle cells when they are oxygen-deprived, like during a sprint race: sugar → ATP + lactic acid 2) Alcohol fermentation, which is used by yeast (a one-celled fungus) and how we make beer, wine, bread, and many other foods: sugar → ATP + alcohol + carbon dioxide In this activity, we will follow alcohol fermentation. Alcohol fermentation begins after sugars enter a cell and are broken down into pyruvic acid. This pyruvic acid is converted to CO2 and ethanol which are waste products, and ATP energy for the cell. Humans have long taken advantage of this process in making bread, beer, and wine. Each of these products relies upon the same fungal microorganism: the common baker’s yeast Saccharomyces cerevisae. Purpose The purpose of this lab activity is to demonstrate that we are intimately connect to respiration through our own cells and by the foods we eat. You will use alcohol fermentation to make bread. Revised Spring 2021 During the activity you will get to see the process unfold over the course of 10 days and get to eat what you create. How's that for a lab? The workhorse of this activity is baker’s yeast. You will combine the yeast with several ingredients in a sealed plastic bag for ten days. During this period, yeast will use the available oxygen for aerobic respiration, and switch to fermentation when the oxygen runs out. This takes time, but it enhances the flavor of the mix. Unfortunately for the yeast, the alcohol they produce eventually builds up and kills them. Our hearts go out to our brave fungal friends. Amish Friendship Bread Below you will find a complete list of ingredients needed for this lab. • • • • • • • • • • • • • • • • • • 4 ziplock bags (gallon size) 1 (0.25 ounce) package of Baker’s active dry yeast 5 cups all-purpose flour 4 cup sugar 3½ cups milk 1 cup of vegetable oil 3 eggs 1 teaspoon of vanilla extract 1½ teaspoons baking powder 2 teaspoons cinnamon ½ teaspoons salt ½ teaspoons baking soda 1 large box of vanilla instant pudding 3 medium-sized loaf pans cooking spray toothpicks OPTIONAL: 1 cup of pecans OPTIONAL: ½ to 1 cup of raisins bananas, coconut, cherries, applesauce and other items may be used according to your preference. You will also need a digital camera (such as a smartphone, webcam, or standalone camera). Procedure Before you begin, read all instructions completely. When asked, take selfies so your experimental setup and your face are visible in each of your pictures. Failure to do so will result in a grade of zero. For 10 days you will work your dough mix, called the “starter”, in a sealed plastic bag. During this period the starter will bubble and ferment, causing the bag to expand like a balloon. This is completely normal. You can let the air out if needed, but you need to remove as much air as possible before you seal it again. Day 1 Gather the following materials: Revised Spring 2021 • • • • • • 1 (0.25 ounce) package of Baker’s active dry yeast ¼ cup warm water (110 degrees Fahrenheit or 45 degrees Celsius) – hot tap water is fine 1 cup all-purpose flour 1 cup sugar 1 cup milk Digital camera (phone, webcam, standalone camera, etc.) In a small bowl, dissolve yeast in water. Let stand 10 minutes. In a gallon zip lock bag, combine 1 cup flour and 1 cup sugar. Mix thoroughly or flour will clump when milk is added. Slowly add 1 cup milk and the dissolved yeast mixture. Close the zip lock bag and place on the counter in the kitchen. This is your starter mix, or “starter”. Take a picture of your starter; your face must also be visible in this image. Days 2-5 On each day, pick up the zip lock bag and mix and mash the contents well with your hands - do not open the bag when mixing. Avoid opening the bag unless absolutely necessary (i.e. the bag is about to burst). If you do open the bag, follow the instructions under “Procedure” on the previous page. Day 6 Add the following ingredients to the bag: • 1 cup of all-purpose flour • 1 cup of sugar • 1 cup of milk Be sure to mix these into the bag contents well. Close the bag and place it back on the countertop. Take a picture of your starter; your face must also be visible in this image. Days 7-9 On each day, pick up the zip lock bag and mix and mash the contents well with your hands, then open the bag and release the air inside. Then close the bag, mix it well, and place it back on the counter. Day 10 Add the following ingredients to the bag: • 1 cup of all-purpose flour • 1 cup of sugar • 1 cup of milk Be sure to mix these into the bag contents well. Take a picture of your starter; your face must also be visible in this image. Then follow the steps below. After you have added the ingredients above and mixed them well with the contents of the bag, you can continue to the next part of the lab on Day 10. Be sure to remove the air from the bag. 1. Get 3 new gallon zip lock bags and place 1 cup of the mix from your starter bag into each. Squeeze the air out and seal them. Take a picture of your 3 bags; your face must also be Revised Spring 2021 visible in this image. You can give these bags to family and friends so they can make their own bread – this is why it’s called “friendship bread”. 2. In your starter bag, you should have about a cup of the starter left. Add the following ingredients to it, then mix well. • 1 cup of vegetable oil • 3 eggs • ½ cup of milk • 1 teaspoon of vanilla extract 3. In a separate bowl, combine the following ingredients: • 2 cups all-purpose flour • 1 cup of sugar • 1½ teaspoons baking powder • 2 teaspoons cinnamon • ½ teaspoons salt • ½ teaspoons baking soda • 1 large box of vanilla instant pudding Below are optional items you can add to the bread: • 1 cup of pecans • ½ to 1 cup of raisins bananas, coconut, cherries, applesauce and other items may be used according to your preference. 4. Pour the contents of your bag into the bowl with the dry ingredients and mix them thoroughly. a. Preheat the oven to 325 degrees Fahrenheit b. Spray 3 medium sized loaf pans lightly with cooking spray and sprinkle cinnamon and sugar all around the sides and bottom lightly. c. Pour the mixture into the pans and sprinkle the tops of the loaves with cinnamon and sugar d. Bake for 1 hour or until a toothpick comes out clean when you check the bread. e. Allow the loaves to cool. f. Take a picture of your baked bread; your face must also be visible in this image. Revised Spring 2021 Analysis Type your answer in bold beneath each question. 1. Based upon the formula for alcohol fermentation, which molecule(s) is/are a food source for the yeast? 2. Based upon the formula for alcohol fermentation, which molecule(s) is/are waste products produce by the yeast? 3. Does alcohol affect the yeast as it builds up in the starter? Explain. 4. Why is it important to prevent air from entering the starter bag during this activity? 5. Did yeast primarily use aerobic or anaerobic respiration in this activity? 6. Suppose that your cells need to harvest at least 25 ATP from every glucose molecule to survive. Would they be able to survive long-term using anaerobic respiration alone? Use your textbook to explain. Questions about the Bread Type your answer in bold beneath each question. 1. 2. 3. 4. 5. Did you follow the recipe completely? If no, what did you change? Describe the flavor. Describe the texture. Did you enjoy the flavor and/or texture? Suppose you wanted to make this bread again. What changes would you make to in ingredients (if any)? Photographs (Figures) Paste your photographs from Days 1, 6, and 10 below (5 images total). Remember to add a caption below each photograph to indicate the Figure # and identify the image. For example: Figure 1: Day 1 starter Lab Observing Osmosis It is difficult to see osmosis occurring in cells because of the small size of the cell. However, there are a few cells that can be seen without the aid of a microscope. This activity will show osmosis in a very large cell – an egg. Read and follow the directions carefully before you begin. I recommend that you build Table 1 in the Results section before you begin; this will give you a place to record your data while you work. Take special care to follow the instructions for providing photographic documentation of your work. Missing or improper photographs will result in a grade of zero. When you are finished, attach and submit your work using the assignment link. Question: How does osmosis occur in an egg cell? Read over the procedure below, then make a prediction about how osmosis will occur in this experiment. Type your prediction below. Materials ? ? ? ? ? ? ? Raw egg 500 mL beaker/container (or large glass/plastic container) 250 mL vinegar 250 mL corn syrup 250 or larger graduated cylinder (or measuring cup) Parafilm (or plastic wrap) Water Procedure Day 1 1. Place the egg into the 500 mL beaker. Pour 250 mL of vinegar over the egg. This will dissolve the shell so water can move across the egg’s membrane. 2. Cover the beaker with parafilm, then take a photograph of your beaker. Your photograph must include your face. 3. After 30 minutes, record your observations in the Table 1. Let stand until Day 3. Day 3 4. Record the appearance of the egg in the data table. Take a photograph of your beaker; your photograph must include your face. 5. Carefully pour the vinegar into a graduated cylinder. Record the volume in Table 1. Note: Measure and record the volume in milliliters (mL). Do not record the depth in centimeters or inches. 6. Rinse the egg off and pour 250 mL of corn syrup over the egg and cover. Let stand until Day 5. Day 5 7. Record the appearance of the egg in the data table. Take a photograph of your beaker; your photograph must include your face. 8. Carefully pour the corn syrup into a graduated cylinder. Record the volume in Table 1. Note: Measure and record the volume in milliliters (mL). Do not record the depth in centimeters or inches. 9. Rinse off the egg and pour 250 mL of water over the egg. Cover and let stand until Day 7. Day 7 10. Record the appearance of the egg in the data table. Take a photograph of your beaker; your photograph must include your face. 11. Carefully pour the water into a graduated cylinder. Record the volume in Table 1. Note: Measure and record the volume in milliliters (mL). Do not record the depth in centimeters or inches. 12. Dispose of the egg and water. Results Use a word processing software (e.g. MS Word) to build a table in which to record your data. Your table should contain 3 columns: 1. Day # 2. Amount of liquid in the beaker (shown in mL) 3. Observations Your table should contain 5 rows: 1. (Column Headings – see 1-3 above) 2. Day 1 3. Day 3 4. Day 5 5. Day 7 Build your table below this line. Add a heading above your table (i.e. Table 1. Descriptive caption). Then enter your data as you collect it. Analysis Type your response in bold beneath each question. 1. In your own words, what is osmosis? Use your textbook to answer. 2. What change to the egg would indicate that osmosis occurred during this experiment? 3. When the corn syrup was removed from the beaker and measured (Day 5), was there more or less than 250 milliliters? Why? 4. When the egg was placed in water (Day 7), did water enter the egg or leave the egg? How do you know? 5. Was your initial prediction correct? Explain. Answer the following using concepts developed from the experiment and reading assignment. 6. Suppose that you water a plant that appeared limp. The next day it appears healthy and tall. In the context of osmosis, explain what happened to the cells of the plant. 7. Roads are sometimes salted to prevent ice from forming. In the context of osmosis, explain how this affects the cells of the plants. 8. The cells of ocean fish are acclimated to salty water. Suppose an ocean fish was removed from saltwater and placed in fresh water (such as a lake or river). In the context of osmosis, explain how the fish’s cells would be affected. 9. Before grilling a steak, you add salt as a seasoning. In the context of osmosis, explain how this affects the cells of the steak. 10. A unconscious, severely dehydrated patient is admitted to the emergency room. What type of saline should be administered to safely rehydrate the patient: Normal (isotonic), Hypertonic, or Hypotonic? Photographs (Figures) Paste your photographs into the space below. Beneath every photograph you must add a footer that numbers the photograph and shows the day on which it was taken. A sample caption is given here: Figure 1. Day One