Wednesday, August 15, 2012

The BE&HM Series ~ Part II: Atoms & The Periodic Table

As I outlined in the introductory post, Biophysical Electrochemistry and Human Metabolism, many of the reactions involved in human metabolism might well be better understood by understanding electrochemistry which deals with redox chemistry and the physical chemistry of ionic gradients and diffusion.  But in order to get to that, I think it is important to lay the groundwork of the chemical nature of all matter.  And while I could send you to any number of tutorials about the net, I thought it worth my while to put the content here.  

Atomic Structure

The basic unit of all matter is the atom.  While there have been all manner of subatomic particles and such in the news, we really don't need to "go there" and the most simplistic model of the atom holds up fairly well for discussions of both biochemistry and electrochemistry.  Atoms are comprised of three particles:
  • Protons:  mass 1 amu, +1 charge
  • Neutrons:  mass 1 amu, 0 charge
  • Electrons:  massless* , -1 charge
The number of protons tells you what you have, and is called the atomic number.  For example the simplest atom is hydrogen, H, atomic number 1 meaning it has one proton.  The next atom is helium, He, with two protons, atomic number 2.  We can't add a proton to an H atom to make it a He atom or remove one from He to make H (we're not going into fission/fusion land here). 
* mass e <<< mass P or N, so negligible in the context of the atomic mass. 

Read more »

No comments:

Post a Comment