Balloon Yeast Fermentation and Cellular Respiration

Balloon Yeast Fermentation and Cellular Respiration

Balloon Yeast Fermentation and Cellular Respiration

Balloon Yeast Fermentation! LAB ACTIVITY OUTCOMES: Explain the reactants and products of yeast fermentation. Relate the process of yeast fermentation to glycolysis in mammals (including humans). Describe observations with the balloons in this experiment and relate them to the process of yeast fermentation. MATERIALS NEEDED FROM YOUR “LAB IN A BOX” KIT Digital scale Weigh boats 100mL graduated cylinder MATERIALS NEEDED FROM THE GROCERY STORE (OR FROM AROUND YOUR HOUSE) 4 empty and clean narrow-necked bottles, such as beer bottles or oldfashioned soda-pop bottles (4) balloons (large enough to fit over the mouth of the 15mL plastic tubes) container of table salt (NaCl) 3 AA batteries package of granulated table sugar Permanent marker or wax pencil 4 packets (1g each) of “Equal”, “Splenda”, or any other sugar substitute of interest Cell phone or other digital camera 4 packets of baker’s yeast Introduction Energy is critical for life.

It fuels all actions in living things, from movement and sensory processing to cell repair and growth. The methods for acquiring and processing energy differ among living things. Heterotrophs get their food from outside of themselves, whereas autotrophs make their own food through the process of photosynthesis. Respiration or Fermentation? Once a heterotroph has consumed food, the sugars from the food must to be converted into a form that is useable by that organism… into molecules known as ATP (adenosine triphosphate). ATP is the molecule responsible for all activity within each cell. When the bonds in the ATP molecules are broken, producing Aerobic Cellular Respiration ADP (adenosine diphosphate) + P (free in a Mitochondrion phosphate), energy is released. In most organisms, the conversion from raw energy (sugar) into usable energy (ATP) is called respiration. Aerobic cellular respiration is the conversion of sugar into a usable form in the presence of oxygen. Thus, oxygen must be present for aerobic respiration to occur. Most ATP is produced in the mitochondria of the cell. Some organisms do not require oxygen at all to break sugar down into ATP; instead, these organisms undergo a process known as fermentation. Fermentation requires an anaerobic environment (no oxygen) and produces byproducts that are different from those produced during aerobic cellular respiration. One of these by-products is alcohol, a major ingredient in beer. Beer is produced by yeast that is undergoing fermentation. If the required materials are not present, this affects an organism’s ability to grow or survive. Factors that can affect an organism’s metabolic pathway include temperature, sugar availability, and the presence or absence of oxygen. Balloon Yeast Fermentation and Cellular Respiration

All of the processes in an organism, from creating molecules to breaking them down, are collectively known as metabolism. In this lab, we will be demonstrating the differences in the metabolic rate (i.e., rate of fermentation) using a variety of energy sources….i.e….can yeast metabolize sugar-substitutes in the same way they do glucose? What about salt? Methods 1. Label your 4 narrow-necked beer or soda-pop bottles “control”, “salt”, “sugar”, and “sugar substitute”, respectively. 2. Using the graduated cylinder to measure, fill each of the bottles with 100mL tap water. 3. Using a weigh boat and the digital scale, weigh out 7g of yeast. 4. Add the 7g of yeast to the first bottle. 5. Repeat steps 3 and 4, above, with each of the remaining 3 bottles. 6. Using a clean weigh boat and the digital scale, weigh-out 4g of salt and add it to the bottle labeled “salt”. 7. Using a clean weigh boat and the digital scale, weigh-out 4g of table sugar (= sucrose) and add it to the bottle labeled “sugar”. 8. Using a clean weigh boat and the digital scale, weigh-out 4g of sugar substitute (“Equal”, “Splenda”, or “Sweet-n-Low”) and add it to the bottle labeled “Sugar Substitute”. 9. Swirl all 4 bottles thoroughly to be sure the yeast has access to the energy source. 10.

Carefully stretch the opening of a balloon over to the tops of each of the bottles. 11. Record your initial observations of activity in the bottles in the data chart below, and then again every 5 minutes for 30 minutes. Answer box: Using a digital camera (such as on your cell phone), take a picture of you (wearing your PPE!) and your experiment, showing your bottles with their balloons (after 30 minutes of reaction)!! Paste this into this table (in .jpg format)!!! Results DATA CHART: Yeast and Energy Source Observations: Your observation should be short, 5 or 10 word descriptions of what you see. Time Control Salt Sugar Sugar Substitute (specify what you used________) Initial Observations (0 min) 5 min 10 min 15 min 20 min 25 min 30 min Follow-up Questions: Answer the following questions: 1. What is the difference between a typical autotroph and a typical heterotroph? 2. Define metabolism. What would cause an organism that normally produces ATP by respiration to switch to producing it by fermentation? 3. In which of your energy source bottles did the yeast show the most activity? Why, from a biological perspective, was this likely the case? 4. Based on what you know about respiration and fermentation, which was happening (respiration or fermentation) in the flasks? What filled (or should have filled) the balloons in your experiment? Created by Brie K. Day Cellular Respiration Cellular respiration is the process cells use to convert chemical energy, or glucose, into ATP – the cell’s energy molecule. The chemical reaction for this process is: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP glucose + oxygen → Carbon dioxide + water + ATP Aerobic respiration is divided into four reactions: glycolysis, which occurs in the cytoplasm of the cell; formation of acetyl Co-A and the Kreb’s Cycle, which occur in the mitochondrial matrix; and the electron transport chain (ETC), which occurs in the inner mitochondrial membrane. In this lab we will compare aerobic respiration in germinated beans and dry beans. Balloon Yeast Fermentation and Cellular Respiration

Study Figure 1 and the model of the mitochondrion in the lab to understand where these reactions take place at. Figure 1: Mitochondria Structure Anaerobic respiration, also referred to as fermentation, does not require the presence of oxygen. In this lab we will study ethanol fermentation in yeast. Fermentation occurs in the cytoplasm only. Fermentation and cellular respiration begin the same way, with glycolysis. However, in fermentation the pyruvate made in glycolysis does not enter the mitochondria and continue the process of breaking it down to extract all of the energy from it. Instead, the pyruvate is shuttled to a series of reactions that will regenerate the NAD+ needed by the glycolysis reactions in order to keep glycolysis running. Yeast break down glucose into ethanol and carbon dioxide, generating 2 ATP in the process. C6H12O6 + → 2CO2 + 2C2H5OH + 2ATP glucose → Carbon dioxide + ethanol + ATP Yeast fermentation produces carbon dioxide and ethanol. This process is widely used by humans to produce bread, wine, and beer. In animals, fermentation produces lactate instead 1 of ethanol and carbon dioxide. Both processes function in generating a supply of NAD + to keep glycolysis running. Figure 2: Overview of Cellular Respiration LEARNING OUTCOMES Explain the effects of germinated and non-germinated beans on the changes in bromothymol blue and relate it to the equation for cellular respiration. MATERIALS NEEDED FROM YOUR ESCIENCE LAB KIT 3 medicine cups 3 beakers 3 rubber bands 100 kidney beans Bromothymol blue 10 mL graduated cylinder PPE kit (lab coat, lab gloves, and lab goggles) 2 MATERIALS NEEDED FROM THE GROCERY STORE (OR FROM HOME) Distilled water Saran wrap paper towels PICTURES NEEDED FOR LAB REPORT “Before and after” photograph of one unsoaked pinto bean sitting next to one of your soaked pinto beans after 24 hours soaking showing the size difference from water absorbed; include your face in the photo.

Photograph of the 3 beakers at the END of the 24 hrs measurement – once you have recorded your last measurement, remove the plastic wrap and take a top-view. I should see the bromothymol blue color in each. Make sure this picture is in focus and the color is able to be distinguished (have adequate lighting). Photo of Table 1: Cellular Respiration and Bromothymol blue. Make sure this photo is in focus and clear so that I can read your results. Check your photo before submitting! INVESTIGATION 1: Observing Aerobic Cellular Respiration Cellular respiration uses glucose and oxygen to produce carbon dioxide and water. In this investigation we will use the kidney beans, both germinated and dry, to observe the process of aerobic cellular respiration. The pH indicator bromothymol blue will estimate the amount of CO2 present in the plastic cups. Bromothymol blue is an acid‐ base indicator. It changes colors based on the solutions pH. When CO2 is produced by cellular respiration, it increases the CO2 concentration in the plastic cup containing bromothymol blue, this causes a decrease in the bromothymol blue pH because the produced CO2 reacts with H2O to produce carbonic acid. This turns the bromothymol blue yellow (acid indicator). CO2 + H2O → H2CO3 (carbonic acid) This reaction is reversible and when CO2 is removed from the solution, it removes CO2 and decreases the carbonic acid present, thus increasing the pH and turning the bromothymol blue back to blue (base indicator). 3 CO2 + Bromothymol blue+ H2O → H2CO3 (carbonic acid) Blue Bromothymol blue → Yellow Bromothymol blue Base → Acid Blue in a base Green at neutral pH Yellow in an acid (pH > 7) (pH 7) (pH < 7) Figure 3: Bromothymol blue indicator Procedure: 1. Label 3 plastic cups with a Sharpie: soaked beans; dry beans; no beans 2. Moisten 3 paper towels with dH2O (distilled water). Place one moist paper towel at the bottom of all 3 plastic cups. 3. Place 50 soaked kidney beans in “soaked beans” cup. Place 50 dry kidney beans in “dry beans” cup. Place zero beans in “no beans” cup. 4. Measure 5 mL of Bromothymol blue using a graduated cylinder. Place 5 ml of Bromothymol blue in 3 small plastic medicine cups. 5. Place each medicine cup inside the 3 larger plastic cups with beans or no beans and the moist paper towels. Be careful NOT to spill the bromothymol blue! 6. Cover the top of each labeled beaker with Parafilm and secure with a rubber band. Be careful NOT to spill the Bromothymol blue in the small beaker! 7.

Place the 3 plastic cups in an area where they will not be disturbed. Let them sit undisturbed at room temperature. 8. Record in Table 1 the initial color of the Bromothymol blue at Time 0 min. Observe the cups every 30 minutes for 1 hour. Fill in the color of the Bromothymol blue in each cup at each 30 minute interval. 4 Table 1: Cellular Respiration and Bromothymol blue Time 0 min Soaked beans cup Dry beans cup No beans cup Blue Blue Blue 30 min 60 min 24 hours Conclusions: What happened? Observation Questions: 1. What is Bromothymol blue an indicator for? 2. Did you see a color change in the Bromothymol blue in any of the cups? If so, which ones and at what time? 3. What is the mechanism driving the Bromothymol blue color change? 4. Identify and explain the control in this experiment. What variables did they eliminate? Why is it important to have a control? Created by Pebble Barbero 5 Photosynthesis Photosynthesis is the process in which plants, algae, and some microorganisms capture light energy and convert it to chemical energy. Balloon Yeast Fermentation and Cellular Respiration

The chemical reaction for this process is: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2 Carbon dioxide + water + light energy → glucose + oxygen In plants, photosynthesis takes place in organelles called chloroplasts. The structure of the chloroplast includes two membranes, a fluid called stroma, and flattened membranous sacs named thylakoids which are stacked in structures called grana. Chloroplasts are mainly found in the leaves of plants, but can also be present in other green parts of a plant. Figure 1: Chloroplast Structure Photosynthesis is divided into two major reactions: the light-dependent reactions that occur in the thylakoid membrane of the chloroplast and the light-independent reactions, or Calvin Cycle, that occur in the stroma of the chloroplast. Observe Figure 1 and the chloroplast model in the lab room to identify the location of these reactions within this organelle. During the light-dependent reactions of photosynthesis, light energy from the sun hits the plant leaf and is absorbed by the pigment chlorophyll. Chlorophyll transfers the light energy through a series of steps to the energy carriers, ATP and NADPH. In the second set of reactions, known as the light-independent reactions or the Calvin Cycle, CO2 from the atmosphere enters the plant leaf and uses the energy from the light-dependent reactions, ATP and NADPH, to make a glucose molecule. Figure 2: Overview of Photosynthesis 1 LEARNING OUTCOMES Students will determine the function of CO2 in the process of photosynthesis, by measuring its consumption by a plant exposed to light. Plot spectrophotometer data of chlorophyll a and chlorophyll b to determine the absorption spectrum for these pigments. MATERIALS NEEDED FROM YOUR ESCIENCE LAB KIT Bromothymol blue 5 test tubes and rack 5 mL bromothymol blue large plastic beaker 10 mL graduated cylinder 100 mL graduated cylinder PPE kit (lab coat, lab gloves, and lab goggles) MATERIALS NEEDED FROM THE GROCERY STORE (OR FROM HOME) Elodea (Anacharis) – from pet supply store Another plant type – leaf from tree/ bush/ flower around house; spinach leaves paper towels PICTURES NEEDED FOR LAB REPORT photograph of you holding your TWO DIFFERENT types of plants: plant leaves and aquatic plant (Elodea/ Anacharis) with your face clearly visible photograph of ALL of the test tubes for the experiment showing the initial color of the bromothymol blue at the BEGINNING of the experiment. photograph of ALL of the test tubes for the experiment showing the final color of the bromothymol blue in all test tubes at the END of the experiment. Lift plant leaves so color of bromothymol blue is visible. Investigation 1: Observing Photosynthesis through CO2 Consumption Photosynthesis uses carbon dioxide and water to produce glucose and oxygen. In this investigation, we will use a living plant, such as the water plant, Elodea, to observe the process of photosynthesis. Balloon Yeast Fermentation and Cellular Respiration

The pH indicator bromothymol blue will estimate the amount of CO2 present in the test tubes. When CO2 is added to a solution in the test tube, it causes a decrease in pH because the CO2 reacts with the H2O to produce carbonic acid. CO2 + H2O → H2CO3 (carbonic acid) This reaction is reversible, so when CO2 is removed from the solution (such as when it is used during photosynthesis), the acid is removed and the pH increases, or becomes basic. Bromothymol blue is an acid‐ base indicator. It changes colors based on the solutions pH. 2 Table: Blue in a base (pH > 7) Green at neutral pH Yellow in an acid (pH < 7) (pH 7) Figure 1: Bromothymol blue indicator When you blow exhaled air through a straw into a solution containing bromothymol blue, you are adding CO2 which reacts with the water to create carbonic acid, thus lowering the pH and turning the solution green first, then yellow if you continue to add CO2. CO2 + Bromothymol blue+ H2O → H2CO3 (carbonic acid) Blue Bromothymol blue → Yellow Bromothymol blue Base → Acid Procedure: 1. Obtain two different plants. Balloon Yeast Fermentation and Cellular Respiration

You will need two leaves (if medium/large) or sprigs (short stem segment with several small leaves) from each plant. For best results, it is preferable if your first plant is an aquatic/aquarium plant (row 1 below). Table 1: Live Plant Options NAME Anacharis Also called Elodea (or any variety of live aquatic/aquarium plant) Fresh spinach leaves Leaves from household plants or outside plants PICTURE WHERE CAN I GET IT? PetSmart PetCo Any pet store with a fish section Any grocery store Sold as a bunch or in bags N/A 2. Using a graduated cylinder, measure out 5 mL of bromothymol blue into a large beaker. Add 45 mL of water to the beaker and swirl to mix. The solution will be light blue (basic pH). 3. Insert one end of a drinking straw into the beaker so the bottom end sits just above the surface of the solution. Do not immerse the straw into the bromothymol blue. Making 3 sure your safety glasses are in place, gently blow through the straw onto the surface of the bromothymol blue. When you need more air, make sure to remove your mouth from the straw before breathing in. 4. Keep blowing until the solution in the beaker changes to a green color (indicating the pH has decreased from basic to neutral). DO NOT keep blowing after it turns green or you will add too much CO2 and your experiment will take too long to finish. 5. Swirl the solution to mix and ensure it is uniformly green. 6. Measure out 10 mL of the green bromothymol blue into each of your 5 test tubes. Number the tubes 1-5. 7. If you were able to obtain an aquatic plant such as Elodea, place a sprig of it into Tubes 1 and 2 (if you don’t have an aquatic plant, place either a sprig or two good-sized leaves of your first plant into Tubes 1 and 2). Place your second plant leaf into Tubes 3 and 4. Tube 5 will not have any plant leaves added – it will be a negative control with solution only. 8. Take Tubes 1 and 3 and cover the two test tubes with Aluminum foil so no sunlight can reach the solution. Place them back on the test tube rack. If you do not have aluminum foil, you can place Tubes 1 and 3 into a dark cabinet for the duration of the experiment instead. 9. Keep Tubes 2, 4, and 5 (two with plant leaves and one with only green bromothymol blue) uncovered and on the test tube rack. 10. Leave the test tube rack in full view of bright sunlight for at least two hours. Balloon Yeast Fermentation and Cellular Respiration

If sunlight is not available, you may use a bright desk lamp ONLY if you can safely bend the lamp so the light shines directly towards the test tubes. 11. After 2 hours, examine all 5 test tubes. Note any changes in the color or appearance of the bromothymol blue solutions in each tube. Record your results in Table 1. Table 2: Photosynthesis and Bromothymol Blue Test tube Plant Type #1: Light Plant Type #2: Light Plant Type #1: Dark Plant Type #2: Dark Bromothymol blue only Initial Bromothymol blue Color Final Bromothymol blue Color Conclusions: What happened? Why? Green Green Green Green Green 4 Conclusion Questions: 1. Why did the bromothymol blue change colors when we blew through the straw into the Erlenmeyer flask? 2. What is bromothymol blue an indicator for? 3. What does the color change in bromothymol blue in the white light indicate in terms of the Elodea? 4. Did you see a change in the color of the bromothymol blue test tube wrapped in Aluminum foil? Balloon Yeast Fermentation and Cellular Respiration

Why or why not? 5. Identify and explain the control in this experiment. Why do we have a control? 6. Carbon dioxide is a greenhouse gas, in part responsible for the warming of the planet. Why do some people believe that planting trees can help in this matter? 7. How does a plant use carbon? What is meant by the term carbon fixation? 8. Hypothesize what would happen to the bromothymol blue, if you had placed your test tube in front of a green light? Would you see a change in the color of the bromothymol blue? Why or why not? 5 Investigation 2: The Absorption of Light by Chlorophyll A pigment is a substance that absorbs light of particular wavelengths. For example, the green color of leaves is due to a pigment called chlorophyll. When white light hits the chlorophyll pigment molecule, the chlorophyll absorbs most of the red, orange, blue and violet wavelengths and it reflects most of the green and yellow wavelengths. That is why the leaf app …