Muscle Contraction Lesson: 3D Printed Sarcomere

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Human: Project #3 - Muscle Contraction: Actin/Myosin Interactions While this model is not the most accurate of 3D models for the actin and myosin bonding process that occurs within muscles, it can help students visualize the interaction in 3D. The original rights to the myosin 3D diagram go to Barak Gilboa of 3D Warehouse. https://3dwarehouse.sketchup.com/user.html?id=0322118571106718978163948 This model was created utilizing his 3D file of a myosin II mini filament inside of Sketchup Print Settings Printer: Flashforge 3D Creator Pro Rafts: Yes Supports: Yes Resolution: .27 Infill: 15% Notes: This is a very long print with these settings if placed on average print speeds. When I printed out the model shown in the pictures, it took about 6 hours to completely print out with added time to remove the rafting. This print file is for the purpose of demonstration to a biology class that can be enhanced by using rubber bands between the actin and myosin filaments to simulate the tension generated by muscle contraction. The print thickness would have to be raised up to at least 50% to withstand the elastic forces from a regular sized rubber band. Post-Printing Finished print at 15% thickness. Some of the protein ends fell apart when printed, so a higher infill is suggested if there is worry of brittleness. This picture does not include other support materials including rubber bands or adhesives to demonstrate the actin/myosin sliding interaction. How I Designed This As stated, I utilized an STL file of a myosin strand in addition to a few rectangles that I drew up and attached to copies of the original file. I utilized a textbook image of a sarcomere and replicated it in 3D. Model creation process & g-coding Standards: NGSS Overview and Background Students in a biology class setting, ranging from introductory high school biology to AP biology, will be utilizing this model of a sarcomere (basic unit of striated muscle) to study and confirm knowledge about the sliding filament theory. Objectives Students will utilize 3D printed models of a sarcomere to complete an assignment on muscle contraction by applying knowledge that is learned from either a presentation or textbook regarding muscle contraction and verifying it in terms of structure and function using this print. Audiences Grades: (7-12) Ages: (12-18) Skill Levels: Basic, Intermediate Subjects: Science Biology AP Biology (molecular) Skills Learned (Standards) HS-LS1-2. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. Lesson Plan and Activity For this project, this is more of a tool to help visualize the sarcomere. It can be enhanced as stated above with the use of rubber bands to attach to the sliding zones of the filament to show muscle contraction. It is recommended that teachers teach the basics of sliding filament theory prior to the use of this print in conjunction with the supporting assignments. Duration of Lesson 2 hours for assignment completion; 6.5+ hours per 3D print. Preparation Requirements The teacher will teach the content knowledge prior to printing out the sarcomere. The teacher will pre-print a sarcomere print for the classroom or for groups (will require at least 6.5 hours per print). Students will interact and study the 3D model with any additional enhancements to the print to replicate the sliding filament theory. Teacher will hand out assignments and guide students over the theory in comparison to the model being used to evaluate that theory. Students will complete and review the worksheet(s) with the teacher. References Inspiration References http://www.nextgenscience.org/topic-arrangement/hsstructure-and-function- Next Generation Science Standards (NGSS) For Reference Rubric & Assessment See attached worksheet/packet and answer key. Handouts & Assets See attached worksheet and pictures of the print.