Week 7 Lab 8 Cellular Respiration

docx

School

South Texas College *

*We aren’t endorsed by this school

Course

1408

Subject

Biology

Date

Dec 6, 2023

Type

docx

Pages

Uploaded by UltraProton9047

Note: All your answers to questions must be in Red or other color (not including blue) for easier grading. Points will be deducted if you do not distinguish your answers. Lab 8. Cellular Respiration Objectives  Distinguish between aerobic and anerobic respiration.  Identify chemical equations for aerobic and anerobic cellular respiration.  Relate the reactants and products of aerobic and anerobic cellular respiration to their respective equations.  Describe and explain the purpose, conclusion and use of materials for the aerobic respiration experiment.  Explain the effects of germination and non-germination of beans on cellular respiration.  Describe and explain the purpose, conclusion and use of materials for the anaerobic respiration experiment, fermentation.  Explain the effects of different food sources on the efficiency of fermentation by yeast. Vocabulary:  Anabolic  Catabolic  Cellular respiration  Fermentation  Anaerobic respiration  Respirometers  Potassium carbonate  Pyruvate Introduction: Metabolism is the sum of all chemical reactions in a living organism. These reactions can be catabolic or anabolic. Anabolic reactions use energy to actually build complex biomolecules (think of anabolic steroids building muscle mass). The energy for anabolic reactions usually comes from ATP, which is produced during catabolic reactions. Catabolic reactions break down (molecules such as glucose) complex biomolecules, such as carbohydrates and lipids and release the energy stored within. Cellular respiration is a catabolic process that

produces the ATP needed to run cellular processes that require energy . Aerobic respiration requires oxygen as the final electron acceptor. (Cellular respiration with oxygen – 32 to 36 ATP, it’s a range not a finite number). Anerobic respiration does not require oxygen, produces MUCH less ATP. Fermentation does not require oxygen and produces much less ATP than aerobic respiration (called Anerobic respiration). The equation for alcohol fermentation is below. C 6 H 12 O 6 → 2CO 2 +2C 2 H 5 OH+2ATP Cellular aerobic respiration begins with complex biomolecules and oxygen . Carbon dioxide and water are products of the series of reactions involved in cellular respiration. The equation for aerobic respiration is below. C 6 H 12 O 6 + 6CO 2 → 6CO 2 + 6H 2 O + 36 or 38 ATP Part 1: Measuring the Rate of Cellular Respiration using CO 2 Background Information: Measuring the rate of cellular respiration can either rely on measuring the amount of oxygen taken in, or the amount of carbon dioxide being released. The Vernier CO 2 sensors are devices that measure these types of gas volume changes, and therefore provide information about the rate of cellular respiration. We will measure the rate of aerobic cellular respiration in beans by measuring the amount of CO 2 . Oxygen consumption cannot be measured simply by putting beans in the test tubes because beans are also producing CO 2 . Any change in gas volume will be due to both O 2 consumption and CO 2 production . In this lab you will be determining the effects that germination has on bean seeds and their cellular respiration. You will be analyzing three conditions: 1. Dry, non-germinating beans 2. Soaked, germinating beans 3. Glass beads Before you begin, create a question and hypothesis regarding the production of CO 2 in the tube containing germinated bean seeds.

Question: Do beans go through cellular respiration during germination? Hypothesis: Germinating beans vs non-germinating beans will generate more CO2. Materials:  Germinating beans (left overnight with plenty of water)  Dry non-germinating beans  Plastic/glass beads  (1) Vernier CO 2 sensor  (1) 250 mL Nalgene Bottle  (3) Weighing boats  Electronic scale  Smartphone with application Vernier Graphical Analysis. Procedure: 1. Obtain three weighing boats and measure 30 g of germinating beans, glass beads, and dry non-germinating beans. 2. Using the Vernier Graphical Analysis application, ensure that your CO 2 sensor is connected. 3. Set it up to record for 3 minutes every 30 seconds. The application will record your data. 4. Place the glass beads in the Nalgene Bottle and secure the CO 2 sensor over the opening of the bottle. 5. In the application click “Collect” to start recording your data. Record your data in Table 1. 6. After 3 minutes, remove the CO 2 sensor and let it air out for 1 min. 7. Reinsert the CO 2 sensor and repeat steps 5-6 to obtain three trials. 8. Remove the glass beads and replace them with the dry non- germinating beans. Repeat steps 3-7. Record your data in Table 2. 9. Remove the dry non-germinating beans and replace them with the germinating beans. Repeat steps 3-7. Record your data in Table 3. Results: Table 1: Glass Beads CO 2 Time (s) Trial 1 Trial 2 Trial 3 Average 30 408 418 431 419 60 407 415 424 415.333 90 406 413 424 414.333 120 408 411 424 414.333 150 408 408 426 414 180 410 410 421 413.666

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Table 2: Dry Non-germinating Beans CO 2 Time (s) Trial 1 Trial 2 Trial 3 Average 30 425 437 462 441.333 60 426 434 464 441.333 90 425 431 464 440 120 423 432 465 440 150 421 429 464 438 180 425 430 466 440.333 Table 3: Germinating beans CO 2 Time (s) Trial 1 Trial 2 Trial 3 Average 30 525 1189 1289 1001 60 620 1382 1481 1161 90 735 1545 1631 1303.666 120 859 1684 1742 1428.333 150 988 1807 1843 1546 180 1150 1915 1935 1666.666 Graph: Graph your data below. There will be 3 separate graphs. Draw a line of best fit for each data set. Online classes should use the following video as a reference on how to graph your data. https://youtu.be/tPuk5HpkHUI

10 40 70 100 130 160 190 430 432 434 436 438 440 442 f(x) = − 0.01 x + 441.67 Dry Non-germinating Beans CO2 Measurements Time (s) CO2 Measurements (ppa)

Respiration Rate: The slope of your lines will represent the respiration rate of each of your samples: Germinating Beans: y = 5.7063x + 719 Non-Germinating Beans: y = -0.0143x + 441.67 Plastic/Glass Beads: y = -0.0583x + 421.96 Conclusion: 1. Did the CO 2 in the glass bead trial change? Yes, the CO2 in the glass bead trial did fluctuate up and down in muffled amounts. 2. What was the purpose of testing a bottle with only plastic/glass beads in this experiment? The glass beads are the control, and the purpose of this experiment is to identify counterfactors such as changes to atmospheric pressure or temperature other than the variable being tested. 3. Which condition produced the most CO 2 gas? The germinating beans had a higher cellular respiration rate than non-germinating beans. Explain why this is the case: Because beans are seeds and cannot perform photosynthesis, they rely on the energy and nutrients stored

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

within them to support germination; therefore, a little cellular respiration was taking place but not enough for growth. 4. Was your null hypothesis supported by your data? Why or why not? It was supported by data, that germinating beans (seeds) turn out more CO2 because non-germinating beans (seeds) are dormant using little respiration. Part 2: Anaerobic Respiration - Fermentation Background Information: Recall that fermentation is the process of cellular respiration that happens without oxygen, thus it is called anaerobic respiration . Fermentation does not require oxygen and produces much less ATP than aerobic respiration. During fermentation, only 2 molecules of ATP can be generated for one molecule of glucose. Pyruvate is a waste product produced during glycolysis, and unless pyruvate is metabolized, it will prevent fermentation from proceeding. There are two ways that pyruvate can be metabolized. In yeasts and certain other microbes, pyruvate is turned into ethyl alcohol (ethanol). In animals and some bacteria, pyruvate is turned into lactic acid. We will investigate fermentation by measuring the amount of carbon dioxide produced by yeast. The rate of cellular respiration is proportional to the amount of CO 2 produced (see the equation for fermentation above). It will be assumed that the ease of fermentation correlates with the amount of carbon dioxide given off. In this experiment, we will measure the rate of cellular respiration using either distilled water or one of four different food sources metabolized by yeast in an anerobic environment. The equation for alcohol fermentation is below. C 6 H 12 O 6 → 2CO 2 +2C 2 H 5 OH+2ATP Before you begin, create a question and hypothesis regarding the efficiency of fermentation for the food sources. Question: Do foods that are high in carbohydrates/sugars produce higher levels of CO2 during fermentation? Hypothesis: Food sources (monosaccharides) produce higher levels of CO2. Materials:

 4 large test tubes  4 small test tubes  Yeast – stir to completely mix the solution before collecting.  Glucose solution  Maltose solution  Fructose solution  Water  Test tube rack  Water bath/incubator at 37 ° C  Plastic/Glass pipettes  Wax pencil  Timer Procedure: 1. Obtain 4 fermentation tubes. Using a wax pencil label fermentation tubes: 1, 2, 3 and 4. 2. Fill each of five small test tubes with 15 mL of yeast suspension, previously prepared. Be sure to mix the yeast suspension immediately before adding it to the tubes. Tip the fermentation to ensure the column is free of any bubbles 3. To each of the fermentation tubes add 7 mL of each of the solutions listed below. Each tube will not be filled to exactly the same level as these tubes are handblown glass.  Tube 1 – 7 mL of glucose (a monosaccharide)  Tube 2 – 7 mL of fructose (a monosaccharide)  Tube 3 – 7 mL of maltose (a disaccharide)  Tube 4 – 7 mL of distilled water 4. Be sure to mix the contents of the fermentation tube to ensure there are no bubbles in the column. Record any initial gas height in your table. 5. Place the four test tubes in a 37 ° C water bath/incubator and record the time. 6. The tubes should be incubated for 10 min. However, you should check them every 2 minutes. When the gas bubbles for one of the tubes are halfway down the column, take all the fermentation tubes out. 7. Record the time when the tubes were removed from the incubator.

8. At the end of the experiment measure the final height of the gas bubbles see Figure 1 . Record this data in Table 4 . Figure 1. Measure the height of the bubbles using a metric ruler. Results: Table 4: Fermentation of Various Sugars by Yeast Fermentat ion Tube Food Source Initial Gas height (mm) Final Gas Height (mm) Net Change Ease of Fermentat ion 1 Glucos e 0 mm 98 mm 98 mm Rapidly 2 Fructos e 0 mm 68 mm 68 mm Moderate 3 Maltos e 0 mm 66 mm 66 mm Moderate 4 Distilled Water 0 mm 5 mm 5 mm Steady (slow)

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Start Time: 0 End Time: 8 min. and 50 sec. Total time: 8 min. and 50 sec. Create a BAR graph in excel using your data for the net change of gas/ bubbles produced. Conclusion: 1. Explain your results for fermentation tube 1 (Glucose). During fermentation of glucose by yeast, it produces CO2 and ethanol. In TT1, there are fewer bubbles produced at the top, in the absence of oxygen, yeasts convert glucose into ethanol and CO2. Fermentation took place with no oxygen, aka anaerobic respiration. 2. Explain your results for fermentation tube 2 (Fructose). Fructose molecules are much smaller allowing fermentation to occur quicker but also heat sped up the rate of fermentation, the more CO2 is released by yeast. The large bubble in the tube is the amount of gas (CO2) that is collected at the top of the fermentation tube which shows that it fermented efficiently. 3. Explain your results for fermentation tube 3 (Maltose). In TT3, maltose fermentation is slower than glucose fermentation because yeast needs to break down maltose into two glucose molecules before it can metabolize it. Of course, other factors that affect the process of significantly less CO2 production are temperature

and the amount of time elapsed. 4. What was the most efficient/easiest sugar for yeast to utilize for fermentation, explain your answer. For yeast to utilize for fermentation, glucose is the most efficient. The reason is that it requires the least amount of energy to make the most product and so if another type of sugar was used, then the yeast would have to use up some of its energy to convert it into glucose. 5. Was your hypothesis supported by your data? Explain why or why not. Yes, the hypothesis was supported, both glucose and fructose create the most CO2 during fermentation because they have the most sugar in them. Licenses and Attributions:  " Investigation: Cellular Respiration" by LibreTexts is licensed under CC BY-NC-SA 3.0 .  " Cellular Respiration " by LibreTexts is licensed under CC BY-NC-SA 3.0 .

Week 7 Lab 8 Cellular Respiration

Related Documents