Tuesday, September 09, 2008

Who am I?

Who am I?  It's a different question than "What am I?"
    In freshman biology, Dr. Goff wheeled a cart of chemicals into the room.  He then lectured on the most common elements found in the human body, along with a catchy little way to remember them: C. HOPKINS CaFe.  (Carbon, hydrogen, phosphorous, potassium, iodine, nitrogen, sulfur, calcium, and iron).
    I'd love to know my elemental composition.  How many grams of carbon am I made of?  Hey, that's not enough: how many different compounds am I made of, and how much of each one?  (How many spoonfuls of sugar are in me?)
     The reason this blog started is because I came across the word "polymorph" in a paper I'm supposed to be reading.  I looked it up in Wikipedia, and found that polymorphs are basically crystalline isomers: structures with the same empirical formula (ratio of atoms), but vastly different structure.  
     Here's the conclusion from that paper: "As polymorphs of each other, PCN-12 and PCN-12' have not only the same formula after solvate removal but also the same atom-to-atom connectivity.  However, the gravimetric hydrogen uptake of PCN-12 is 27% higher than that of PCN12' [sic] at 77K and 1 bar.  The reason behind these remarkable improvements can mainly be attributed to the 'close-packing' strategy, namely, the formation of cuboctahedral cages and the unique arrangement of open metal sites in each cuboctahedral cage in PCN-12.  This strategy may have general implications in the search for a practical absorptive hydrogen-storage material for fuel-cell-driven cars."  (Wang, X.; Ma, S.; Forster, P.; Yuan, D.; Eckert, J.; Lopez, J.; Murphy, B.; Parise, J.; Zhou, H. "Enhancing H2 Uptake by 'Close-Packing' Alignment of Open Copper Sites in Metal--Organic Frameworks."  Angew. Chem. Int. Ed. 2008, 47, 7263-7266.
     Whew!  So two crystals have the same ratio of atoms, the same connectivities, and vastly different hydrogen storage potentials.  It truly seems that "it's what you do with what you have that makes the difference."
      I could take that in a whole different direction, but my point is this: knowing the composition of something is great, but it's not the whole picture.
     Examples abound: C6H12O6 may sound pretty specific, but this formula describes quite a number of sugars, from glucose to galactose to fructose, and beyond!  And speaking of sugars, a single glycosidic bond distinguishes cellulose from starch, determining your ability to digest the carbohydrate in which it's found.  And speaking of picyuny, enantiomers (molecules with identical atoms and connectivities, but different arrangement about another atom) can have vastly different biological activities.  To picture this, try to imagine putting a leather left-handed glove onto your right hand.  As similar as your two hands are, there's somethings that are specific to one or the other!
     So composition isn't everything: do I make my point?  Of course, it is something.  That's why atomic absorption spectroscopy is alive and kicking!
    But as a wiser head than mine has said: the sum is greater than the whole of its parts.  Say I could determine not only my own elemental composition, but the exact mass of every compound I am composed of.  What's  the number of kilograms I am in total (not telling), the grams of water vapor in my lungs, the milligrams of vitamin C being absorbed in my small intestine, the attograms of iron complexed to cytochrome P450 in my mitochrondria, or the zeptograms of synapsin flitting between the synapses of two of my axons?  But of course, this level of detail isn't enough to really know what I am.  I'm not just interested in what the mass of DNA in my body is.  How is it and every other molecule distributed in three-dimensional space?  What's its sequence?  What random mutations are occurring in it?  Based on my genome, what are the diseases I am most prone to?
     If I knew all of these things, would I know myself?  If you knew all these things, would you know me?  No, you might say.  I know your eyes are blue without knowing what pigment is present in them, which stretch of your DNA encoded the protein or proteins responsible, or which parent you inherited that stretch from.  I don't know which antigens you are sensitized to, which you have a passive immunity to, and which you've developed an active immunity to.  I don't know the localization of antibodies or B cells in your lymph nodes, but I do know that when you use Crest toothpaste, bad things happen.
    But even a knowledge of someone's physical attributes or sensitivities isn't the same as knowing that person.  That just means you've read their file: not that you can predict what card to put down if you're playing Apples to Apples with them.
    Is it possible that the essence of a person is something beyond their physical body, either on the micro or the macro scale?
    Think for a minute about identical twins.  Have you ever known twins?  Where there ones you could tell apart, or some that you couldn't?  They've been involved in quite a few different research projects.  After all, if someone has the same DNA as another person, shouldn't they have quite a few other things in common? But wait: why isn't everything in common?  Oh yes: random expression of proteins can produce variations in fingerprints, and variance in freckles, along with other things.  And anyway, how could you expect two people -- even with the same genome -- to have the same volume of organs, number of cells, synchronized secretion of identical volumes and concentrations of hormones?  
    Well, other factors can cause differences as well.  Environment plays a huge role.  If two twins are separated from birth, and one is adopted by a Korean couple while the other is adopted by an Estonian couple, the twins are going to have very different mores.
    All right, cut to the bottom line: what makes a person a person?
Is it the mass of elements, or the mass and distribution of compounds in their body?
Is it the complexity and order of their body, and their ability to form thoughts?
Is a person the sum total of their genetics and environment?

Hold it, hold it!  What about a third, and vital component -- the will!  

How can elements or compounds explain the will?  How can environment explain the will?  What can explain the will, besides the presence of a soul and spirit?

Matter and environment alone cannot explain what it is that makes a person a person.  I am what I am, partly through the DNA my parents gave me, and partly through the influence they have in my life.  But I am also who I am because of the choices I have made.

And If you truly know me, you know me not because of what I look like or you know how I grew up, but because you recognize my spirit.


macihms_dad said...

Dearest you are a Princess, a child of the King. You are a body, soul, and spirit. You have a mind that makes connections in amazing ways. I love reading your thoughts. I am so happy I finally got this comment thing figured out. LOVE, me

eve said...

Aw, man. I'm just glad you got a kick out of it! :-)