The Scale of the Biological World 100 mm 1x10-4 m Plant & Animal Cells Bacterial Cells 10 mm 1x10-5 m 1 mm 1x10-6 m Viruses 100 nm 1x10-7 m Proteins Another thing that affects cells is nanostructure. The reason that cell are so affected by the nano world is that they are made up of proteins that are on the nanoscale and the proteins they interact with in their environment are that same scale. The cells world is on the micro and nanoscale. 10 nm 1x10-8 m Small Molecules DNA 1 nm 1x10-9 m Atoms 1 Å 1x10-10 m All images from Google Images

Nanoscale Fits the Molecular World One 5’5” Student A 8’ desk? A 2’ 6” desk? Or a 5’ desk? Here we have an example of how having things at the proper scale can affect an environment. In this case the environment of a student. The student can only sit functionally at a properly scaled desk. This is how micro and nanostructure change the way cells react with their environment. Compared to what we can see, an atom scale is about a million times smaller! Imagine a desk a million times too big!

Micro and Nano-materials Have More Atoms on the Surface Materials of the micro (1x10-6m) and especially nano (1x10-9m) size have more atom exposed on the outside then inside Volume = 18x19x1 nm3 or 15x8x16 atoms = 1920 atoms total 976 or 51% of the atoms are at the surface Nanomaterial A 1x1x1 cm3 cube will have 0.00072% of the atoms exposed to the surface Volume = 3x3x0.7 mm3 or ~4 million atoms total 976 or 4% of the atoms are at the surface Micro-scaled Material

Surface Atoms Interact more with the Environment Light Temperature Heat Cold Sound The forms of energy that affect us in the environment can affect molecules. Energy comes from the environment to affect molecular nature. Since more molecules are on the surface, the affect is more pronounced. All images from Google Images