3. Clothespins and Glycogen

STEM activities for afterschoolThis simple exercise in physiology from Carnegie STEM Girls will illustrate how the human body taps into stored reserves of glycogen to generate adenosine triphosphate (ATP) proper functioning. To promote teamwork, group students together and have them rotate roles. Have one student set a timer on a stopwatch, another will record results on a piece of paper, and the final group member will open and close the clothespin as many times as possible in one minute. As the student who is recording writes down this figure, the child who is holding the clothespin will continue into a second minute without stopping. Students should compare the frequency of opening and closing within the first minute with the second. Have students repeat the exercise and switch roles until every member has performed every responsibility.

We love this activity because it tackles complex functions of the body if appropriate for your grade level while giving all students practice generating, recording, and analyzing data. Ensure this is a true experiment by having groups predict whether the rate will be faster in the first or second minute and explain their reasoning. Then have them compare their hypotheses with the actual results as a large group.