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  • General

    Restrânge toate secțiunile Extinde toate secțiunile

    Author: Laura Tomlin, Salado Middle School, Salado, TX

                 Frances Dellutri, NSS Director of Education

                 Assisted by: Natalie Orrantia, Univ of Chicago                   Updated:  August, 2023




    Summary

    Microgravity has been determined to have a significant impact on liver function in mice after two weeks in space. This experiment will investigate whether microgravity has an immediate impact on the function of catalase enzymes in the liver, which are responsible for the neutralization of hydrogen peroxide toxin in our bloodstream.  Reactants for this experiment will be 1 cc of food-grade, pureed calf liver and 1mL 3% over the counter Hydrogen peroxide. 

    Students will gain valuable experience in chemistry, anatomy, current space research topics, microgravity, engineering, experimental design, and critical thinking, even before viewing results from the actual flight.

     These projects can be modified to suit any classroom.

    Age of Students: 11+ years


    Image shows author Laura Tomlin aboard parabolic flight, completing our enzymatic experiment


    Project Goals: 

    • To investigate whether microgravity inhibits catalase enzyme activity in the liver. 

    • To demonstrate how gravity is a constant in our lives, and how a change in gravity affects the motion of all matter. 

    • To engineer an apparatus which can be used to conduct and contain a chemical reaction in microgravity. 

    • To provide an authentic learning experience  for students which deepen understanding of force and motion, space exploration, human anatomy, the effect of space flight on human health, engineering design process, and scientific inquiry.





    Keywords/Topics Covered:

    Gravity, Microgravity, Chemical Reactions, Body Systems, Engineering, Scientific Inquiry, Anatomy  GIF of human anatomy, showing primary organs of the body: Heart, Lungs, Liver, Stomach, Intestines, etc.  

                                                                                                                                                                               Image Credits to GIFGIFs services

    US Next Generation Science Standards (NGSS)

    • Properties of Matter PS1.A

    • Force and Motion PS2.A, PS2.B

    • Space Systems  ESS1.A, ESS1.B

    • Matter and its interactions PS1.1, PS1.2, PS1.4, PS1.5, PS1.6

    • Energy PS3.2, PS3.4

    • From Molecules to Organisms: Structures and Processes LS1.1, LS1.2, LS1.3

    • Ecosystems, Energy, and Dynamics LS2.4, LS2.5

    • Engineering Design ETS1.A, ETS1.B, ETS1.C



                                                                             GIF showing a tiny two-legged turquoise robot in a walking animation to the left Image Credits to GIFGIFs services

    Required prerequisites / prior knowledge:

    • Basic Engineering design process

    • Scientific Inquiry                                                               

    • Forces and Motion: Newton’s Laws, balanced and unbalanced forces, gravity, microgravity, capillary force, adhesion, cohesion

    • Space Science- Space Research

    • Organ Systems, Liver function

    • Chemical properties of matter

    • Indicators of a chemical change


    *All GIF animations credited to GIFGIFs Services*

  • Chemistry Simulations: Foundations For Student Knowledge

    1. Reactants, Products, and Leftovers:

    This simulation is depicting chemical reactions and reactant combinations, what happens to our reactants and what can we except? 

    Screenshot of PhET lab: Reactants, Products, and Leftovers
    Screenshot of simulation above shows creation of water molecules: Combining hydrogen and oxygen to create H2O, leaving leftover H2 and O2 molecules!

    https://phet.colorado.edu/en/simulations/reactants-products-and-leftovers 


    2. Balancing Chemical Equations: 

    This simulation teaches the fundamental skill of balancing a chemical equation, fostering the understanding of molecular representations of matter, what happens when chemicals/reactants combine? 

    Screenshot of PhET lab: Balancing Chemical Equations, showing screen depicted when equation is successfully balanced
    Screenshot of simulation above shows the balancing of an equation: The equation shows varying amounts of reactant/product for the combustion of methane.

    https://phet.colorado.edu/en/simulations/balancing-chemical-equations 

  • Setting Up Our Experiment

    Background of Lesson:  

    This is a student driven, authentic research experience provided by Wisconsin Space Grant’s Embedded Teacher Program.  The purpose of this experiment is to determine whether microgravity will suppress catalase enzyme activity in calf liver.  Students designed equipment and procedures for weightlessness aboard the Zero-G parabolic plane, and conducted the experiment at 1-G in the classroom. 

    The experiment was subsequently taken on board the Zero-G parabolic plane and repeated in a microgravity simulated environment.


    Watch the following videos for crucial background information on the regular functions of the liver as well as the functions of a catalase enzyme in a consistent environment!

    Functions of the Liver Video: 
     



    Catalase Enzyme Demonstration Video: 
     




    Students are first introduced to exothermic chemical changes requiring a catalyst with the classic elephant toothpaste reaction (Activity 1).  Students then learn about a similar reaction that occurs in our body- the breakdown of hydrogen peroxide by our liver. Students conduct a short lab experiment in class to investigate how liver damage results in less catalase enzyme activity in our liver, resulting in little to no breakdown of hydrogen peroxide (Activity 2).


    Students must complete activities 1 and 2 to continue with the experiment:
    Links to these activities found as a file under section heading! 
     GIF showing a counter holding several beakers and test tubes, each with a different colored substance!
    Image Credits to GIFGIFs services



    After understanding the role that catalase enzymes and environmental stress play in the breakdown of toxins passing through the liver, students must brainstorm and engineer an apparatus to be used to test catalase enzyme assay in a weightless environment within a 20 second time frame. Students needed to work under the weight, size, and safety constraints required for flight on the Zero-G parabolic plane. Special care was taken to design an apparatus that could contain blood and withstand pressure buildup inside the reaction tube, the apparatus students will use today! 



    Student Lesson Prep: Liver Function in Microgravity

    Ensure students have completed activities 1 and 2 before moving forward! 


    Broad Research question: How does long term space travel affect the liver and other aspects of human health?

    This question cannot be answered with one experiment, but use this lesson to think about how long term space travel can affect different aspects of our health! 


    Purpose of Our Lesson:  Does short term exposure to microgravity affect how catalase enzymes function in the liver?


    GIF of a yellow light bulb, flashing as it turns on!

    Create Your Own Hypothesis!

    Using the knowledge you gained from activities 1 and 2, form a hypothesis about the results you expect to see from this experiment in 1-g versus 0-g: 

    • Focus on writing your hypothesis with "If, Then" statements! 

    • "If                     , then                   ." 
                                                                                                                                                                            
    • Have the first blank be what is being changed, and the second blank be the outcome you expect to see as result!           

                                                                                                                                                                                                                               Image Credits to GIFGIFs Services


    Here's a short video if you need a little more help visualizing your hypothesis:

     


    • resource icon
      Activity 1 ! Fișier

      Elephant Toothpaste Experiment: Student's first introduction to exothermic chemical changes requiring a catalyst, important to set foundation for the experiment later on! 

    • resource icon
      Activity 2 ! Fișier

      Liver Damage Experiment (precursor to the main Liver Enzymatic Activity experiment): Students investigate how liver damage results in less catalase enzyme activity in our liver, established important background information for one of the main topics of our lesson. 

  • Apparatus and Procedure

    GIF of a meerkat/rodent mixing chemicals in a laboratory setting.

    Materials

    • ¼’’ Nylon Tube

    • Soft Silicone (often times in cure form, like glue)

    • Quick Release IV Clamp 

    • Hydrogen Peroxide

    • Common Syringe 

    • Calf Liver Puree 

    • Latex Balloon                                                                                                                                                 Image Credits to GIFGIFs Services

    • Zip ties

    • Recording Device (can be your phone!)




    Diagram of constructed apparatus, labelling distinct parts such as "quick release clamp" and "calf liver puree"

    Building Our Apparatus 

    Construction of catalase enzyme assay:

    • Cut ¼” interior diameter nylon tube to a length of 10 cm.

    • Seal end ONE END of tube with soft silicone

    • Inject 1 mL of hydrogen peroxide into tube

    • Clamp tube in middle with a quick-release IV clamp, so that the hydrogen peroxide is separated on one side within the tube, having the other side empty

    The quick-release IV clamp should be tight enough to keep the reactants separate until it is time for reactants to come in contact with each other.

    • Inject 1 mL of calf liver puree into the nylon tube, separate from the hydrogen peroxide in the empty side from the clamp division

    • Stretch a small balloon across open end (closest to the liver), and secure with a zip tie 

    The purpose of the balloon is to avoid pressure build-up within the tube due to oxygen gas production during the reaction.




    Diagram displaying the same constructed apparatus, after reactant combination has taken place, showing breadth of experiment.

    Experimental Procedure
    • Begin recording your video

    • To initiate the reaction, unclasp the clamp 

    • The tube will be given a quick shake to mix the reactants.  

    The presence of bubbles indicates the breakdown of hydrogen peroxide by catalase enzymes in the liver.  

    • Watch your video back, record the results after 20 seconds


  • Recording Your Results

    Use the following template to record your results; printable version is attached:

    This same template will be used for the next activity!

    Template used for enzyme experiment data collection, linked as PDF at end of section                   GIF of a professor in front of a blackboard, point at a written "Check it out!"
                                                                                                                                                                                                    Image Credits to GIFGIFs Services



    Make Your Conclusion: 

    Students must write their own conclusions after completion of the in-class experiment. Image of several (undisclosed) students working through enzyme experiment in a 1-g environment.

    A good conclusion, written in essay format, will include: 

    • Include an answer to purpose, supported by data (purpose question asked earlier in lesson)

    • Include a description of the apparatus and how it works

    • Discuss problems with experiment and possible solutions

    • How would you change or improve the experiment? (Was there anything you found difficult?)

    • Why is this experiment important? (Think about the bigger research question!)

  • Post-Flight Activity

    Watch this short clip of our enzyme experiment aboard a zero-g flight: 





                                                                                                                                                                                                                       Image Credits to GIFGIFs Services

    GIF of an astronaut spinning counter-clockwise as if in microgravity.

    Record what you see with the assigned template!    

    Pay close attention to signs of catalase enzyme activity:

    • Is the reactant combination bubbling? 
    • Do you see any type of activity happening at the release of the clamp?  


    Record this new data and compare these results to your original hypothesis! 

  • Additional Resources

    • Anatomy of the Liver

    https://www.stanfordchildrens.org/en/topic/default?id=anatomy-and-function-of-the-liver-90-P03069


    • NASA Technical Archive (searchable)

    https://ntrs.nasa.gov/



  • Send a Postcard to Space!

    Send a Postcard to Space through NSS Supported Blue Origin Club For The Future initiative!

    Visit: SpacEdge Academy Postcards in Space Course