This 10-minute video lesson shows how how myosin and actin interact to produce mechanical force. [Biology playlist: Lesson 47 of 71].
Using modifications of classic biochemical procedures for purifying the muscle contractile proteins, myosin and actin, we devised a 3-hour laboratory on the biochemistry of muscle that is appropriate for students in an introductory college biology course. The protocol begins with the extraction of small pieces of frozen chicken muscle in high salt (enhances myosin recovery) and low salt (enhances actin recovery) buffers. Solubilized myosin is induced to form visible filaments by lowering the ionic strength of the buffer, and a small pellet of enriched myosin is collected by centrifugation. Aliquots of both myosin and actin preparations are prepared for electrophoresis on small SDS, polyacrylamide slab gels. Completed electropherograms are stained, and students determine the molecular weights of gel bands. These data are then compared to known structural models of myosin and actin subunits and fragments.
This lesson covers the topic of muscles. Students learn about the three different types of muscles in the human body and the effects of microgravity on muscles. Students also learn how astronauts need to exercise in order to lessen muscle atrophy in space. Students discover what types of equipment engineers design to help the astronauts exercise while in space.
