Aging, Mitochondria and Free Radicals

Molecules comprises of atoms, which have electrons revolving around their nuclei (much like the planets around the sun, a star; though the forces that govern their rotation are entirely different). To the utter vexation of the electrons, Wolfgang Pauli, a great scientist had laid down his 'exclusion principle' which states that no 2 electrons (fermions) can have the same quantum number. Thus, if 2 electrons are occupy an orbital, they must have opposite spins! They (electrons) still do not complain, as long as they stay paired (like husband and wife : opposite spins!) but when they stay single (unpaired), and uncared for (unshared: not contributing to bond formation), they become agitated and highly reactive. Free radicals are molecules that contain unshared electrons and being highly reactive, pounce on nearby molecules and harm them.

Superoxide anion, hydroxyl radicals and nitric oxide free radicals are some examples. They are grouped into a common category called ROS (Reactive Oxygen Species), since all these free radicals contain oxygen in their molecules. To fight against these free radicals our body has developed its own machinery: speroxide dismutase (SOD), catalase (CAT), glutathione peroxidase are some examples. Vitamin C, E, A and some other nutrients assist them in free radical scavenging and serve individually as antioxidants.

Free radicals particularly attack the DNA, both in the nucleus (nDNA) and in the mitochondria (mtDNA), mitochondria being particularly vulnerable due to its inefficient repair mechanism, and also that the mtDNA is not covered by protective histone coverings. As a result of this assault by free radicals, mutations of genes and even deletions occur in the DNA, specially in the mitochondria. Oxidative phosphorylation, the process by which mitochondria produces ATP (the energy currency of the cell; produced in the mitochondria and disposed off to other locations in the cell, for energy utilization, as if portable batteries), is compromised, ATP production diminishes and the cells begin to die. Thus cumulative genetic damage results in aging.

Related Article: Aging: From a General and Evolutionary Perspective

Of Lightning, Photosynthesis and Electron Transport Chain

We all know that plants use solar energy to form chemical energy in the form of carbohydrates. The suns rays (photons) impinge on the chlorophyll of the green leaves. This excites them and raises them to a higher energy level. These electrons in turn, transfer their energies to another electron nearby and this process goes on till the energy is transferred to the reaction center, where actual conversion of energy is occurring. This energy transfer occurs at a phenomenal efficiency of about 95%. In order to achieve such unprecedented (compared to about 40% in the most efficient solar cells) efficiency, the electrons should 'change hands' in an efficient way and not merely by a random walk.

The electrons do this by 'sensing' and sorting of the energy levels of different electrons (without ever actually having to go to these places for sensing: what Einstein called spooky action at a distance). How the electrons found the right path so as to reach the destination (to electrons with a lower energy level) quickly and efficiently remained elusive. Now scientists perhaps know the reason. These electrons do some kind of quantum computing to arrive at their destinations with unprecedented efficiency.

This premonition of 'unsorted databases' is characteristic of the quantum computing algorithm. Like gamma synchrony, regular patterns of signals lasting several femtoseconds were found, when the chlorophyll molecules were mapped by using electronic spectroscopy. As in dendritic networks, these 'quantum beats' 'bind' (synchronize) all the energy levels of electrons together. Thus these quantum beats help electrons find out the 'path of least resistance' in such an astonishing efficiency. It is as if the energy status of the electrons were indexed as in a computer search algorithm, so that they could be found out faster.

A similar mechanism may be involved in our mitochondria where electron transport chain occurs. Electrons are transported in the mitochondria along a series of electron acceptors to end up ultimately in cytochrome c, where they combine with oxygen, the ultimate electron acceptor, to form water. This chain is very important as it generates ATP, our own energy currency. Quantum entanglement may explain the subject in a new light.

Just a thought in passing, it is said that lightning follows the path of least resistance. I always wondered how it would know where to advance to next, since it had no prior information about what lied ahead. Now, this quantum computational algorithm may be the suitable one to address this issue.