Ecology and Systems Biology: Matter

After reviewing student work, one area that we clearly needed to spend some time revisiting was the concept of matter.  In a system, the amount of matter does not change.  Atoms are the fundamental unit of matter.  When collections of atoms bond together they create molecules.  The key point is that the number of atoms in a system will stay constant, while the bonds between those atoms (the molecules) can change.  Stated another way, the amount of matter stays constant but changes form.  This conservation of matter concept was introduced to students in 9th grade Integrated Science, and it is important that students understand the concept as they continue in their study of biology.  To help visualize the conservation of matter principle, on Friday we watched a segment of the NOVA special “Hunting the Elements” beginning at 47:47 and continuing through the end of class.  The explosions during the first segment of the video were accompanied by explanations of the rearrangement of atoms and release of energy, and students took notes to ensure understanding of the conservation of matter.  Next, students learned about CHNOPS, the 6 main elements found within the human body (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur).  Students recorded the percentage of each element and learned to calculate the percentage of elements reported an pounds.  Depending on time, some classes were able to watch the next segment on trace elements, while others finished with the segment on bacteria living in Yellowstone National Park.  The complete video can we seen below or on Netflix.