Friday, July 18, 2014

Powers of Ten

In A&P, many students have hard time wrapping their heads around the size of things.

For example, how many of us really have a good grasp of how small a cell really is, or a protein molecule within a cell, or an atom within the protein?  Or the relative size of tissues compared to individual cells—or compared to an organ?

And we are continually "zooming our focus" in and out among levels of organization—atoms and ions, molecules and crystals, organelles, cells, tissues, and organs.

Add to that the fact that the units of measurement used to describe the size of things are in the metric system (SI), which is based on powers of ten. That is, we use a measuring system based on units that very by a factor of ten—units are multiplied or divided by ten, then another ten, then by ten again.

Add to that the frequency of discussion of pH units, which on the surface seem to go up or down by single units—but in reality a change from one pH unit to the next is a change in hydrogen ion concentration by a factor of ten.

This nifty little video can help us wrap our heads around the concept of powers of ten.  It may help us in navigating the world of the human body. Click here to see the helpful material that accompanies the video.


DNA image credit: 3Dscience