November 06, 2006

Hand Symmetry and its implications

Look at your left hand and compare it to your right hand. Though the image and form are exactly the same, you cannot superimpose one hand upon the other. This mirror image analogy provides a pathway to understanding the term chiral (Ki-Raal) in next few moments rant. Realize also that the back of your hand is completely different in form and function to the front of your hand - like two sides of a coin. The back of your hand cannot serve the same function as the front of either hand.

Life function is chemistry within a biologic scaffolding. The reactions that species have are based on the inputs of raw materials that interact with a mechanism of supporting that life form. Plants species have a system based on chemical reduction that is complementary to animals systems based on chemical oxidation. The processes of respiration are cyclic and the raw materials produced on one end of a coupled cycle are different than those produced on the opposite side of the coupling. Natural processes on the animal side are chiral lefthanded - so that the physical geometry of the space that causes molecular transformation can compensate in three dimensions.

The rate of this transformation, called kinetics, is dictated by efficiency and conservation of energy. The turnover rate for some enzymes in biologic systems is on the order of 10 to the sixth power - one million per second per enzyme. I have trouble comprehending that rate, but time works differently on different size scales. It is relative. Other enzymes may work at one reaction every ten minutes. But like clockwork, when enough potential energy is built up to enact the reaction, it takes place. If the materials in the pipeline are not correctly fit, like puzzle pieces forced into interlocking, then the rate slows down, but the reaction still happens and the species continues to exist. Life goes on, slower.

The amount of energy required changes as the plant or animal substitutes less efficient elements and molecules for the intented function. The element that holds up a process by not being present at the time it is needed determines the rate - it is the sole rate determining step for the entire process. This governs the entire cycle because everything else is streamlined to take place contingent on the one molecular event. If the right pieces are assembled in the right way, the thermodynamics of the system are said to be favorable. The better the system is set up, the more efficient the system and the faster the rate of turnover.

In plants, energy is stored in complex systems that act like little ratchets. There are co-factors that enable reactions and places to dump energy into reserves that build to a threshhold level, so that they are ready to be enabled when the slowest coupled event starts the chain reaction. The cascade of work causes reproduction based on photo-receptor cells and threshholds start self-contained processes that signal different event cascades through the plant life cycle. Molecules that would better work in a right-handed arrangement are left out - like dead matter waiting for a parellel universe. But biology has figured that out and favors left-handed chiral configurations.

In animals, oxidation pathways are run based on food/fuel cycles that work based on consuming plant or animal stuffs for the energy that sustains life. The output carbon dioxide is used by plants as a raw material, whereas plants produce oxygen and water as byproducts of their metabolic activity. Thus the processes work like the front and back of the hand, not like the left and right hand.

Our hands are what they are, both front and back and side to side, they are hands. If the animal and plant kingdoms are two sides of a coin, then the mechanism that the coins run really must be symmetric and chiral. That suggests that the oxidation side of the process, how humans believe food intake relates to energy, ought to be symmetric to how the plants uptake energy. Instead, we seem to have invented a new wheel - one which the consumption of energy is far in excess of what is needed to sustain the counterbalanced life-forms that earth has traditionally worked from.

Dr. Lenny suggests that we have some theoretical thinking to do with the model that we choose to understand animal based life - that food while necessary for mass-balance, may not in fact be linked to energy at all. The ratchet effect of biological systems may get swamped over in a flood of excess energy, but efficiency and conservation tend to be rules of life. People violate them at our own peril. We also seem to ignore the fact that we have an energy source with no explanation grounded in modern day science. It suggests a reformulation of modern science is necessary.

Thanks for joining me howdtside the baax today. DL

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