Your Inner Locomotive Revealed
Visualize an old locomotive train roaring down the tracks. One of the characteristic images that surely comes to mind is the oscillating motion of the coupling rods on the wheels. The long rods that connected the wheels provided a way to convert heat energy from the steam into mechanical energy (example video on YouTube). It now appears, thanks to a team of German scientists, that your body has trillions of mechanical devices something like those coupling rods. They serve to transmit the energy in the food you eat into mechanical energy, driving a proton pump inside your inner power plant. It’s all part of an amazing series of electromechanical machines in the powerhouses of the cell, the mitochondria.
A team at the Freiburg Institute for Biochemistry and Molecular Biology produced the best-yet look at one of the largest enzymes in the body, NADH dehydrogenase, also called Mitochondrial Complex I. It is an essential part of the respiration process (also called oxidative phosphorylation) that passes electrons, protons and oxygen through a sophisticated energy transport chain so that energy can be stored in ATP molecules – the universal energy currency of all living things. Weighing in at nearly a million daltons (atomic mass units), Complex I, composed of four major parts and shaped somewhat like a hockey stick, produces 40% of the proton motive force used by ATP synthase to produce ATP. Its job is to derive protons from NADH and hand them off to additional cofactors and enzymes in the transport chain that will pump the protons outside the mitochondrial membrane. The electrical potential thus created across the membrane drives the ATP synthase rotary engine at the end of the chain (see 12/22/2003, 04/30/2005 and top of April 2002 page for informative links).
In discussing the paper published in Science Express,1 Science Daily contained some amazing facts about the machinery of respiration and how it delicately handles explosive ingredients:
In a laboratory experiment, hydrogen and oxygen gas would react in an explosion and the energy contained would be released as heat. In biological oxidation, the energy will be released by the membrane bound protein complexes of the respiratory chain in a controlled manner in small packages. Comparable to a fuel cell, this process generates an electrical membrane potential, which is the driving force of ATP synthesis. The total surface of all mitochondrial membranes in a human body covers about 14.000 square meter. This accounts for a daily production of about 65 kg of ATP.
That 65 kg, by the way, is near a typical human body weight. That’s how much ATP your body synthesizes each day – even during sleep. At any one time, though, your body only contains the ATP equivalent of a AA battery (05/31/2010). The electrical potential generated across that 14 square meters of mitochondrial membrane drives the ATP synthesis that keeps you – and every living thing from bacteria to giraffes – alive.
Science Daily compared its action to a locomotive:
The now presented structural model provides important and unexpected insights for the function of complex I. A special type of “transmission element,” which is not known from any other protein, appears to be responsible for the energy transduction within the complex by mechanical nanoscale coupling. Transferred to the technical world, this could be described as a power transmission by a coupling rod, which connects for instance the wheels of a steam train. This new nano-mechanical principle will now be analysed by additional functional studies and a refined structural analysis.
The authors of the paper did not mention evolution. The only oblique reference is that the working parts are “highly conserved” (unevolved) throughout the entire realm of life:
Fourteen central subunits are highly conserved among eukaryotes and prokaryotes. They form the structural core of the two arms of the complex and are essential for its bioenergetic functions. 26 accessory subunits that are not found in prokaryotes are arranged around this core and presumably function in assembly, stabilization, regulation and additional metabolic pathways not directly linked to energy conservation.
Four other times the paper mentioned that key elements of the enzyme are conserved or highly conserved. There was no attempt to explain how this “nano-mechanical principle” emerged or evolved. They did mention, though, that mutations and dysfunctions in Complex I that allow the formation of ROS are implicated in debilitating conditions like Parkinson’s and Alzheimer’s disease – and perhaps in the aging process itself.
1. Hunte, Zickerman and Brandt, “Functional Modules and Structural Basis of Conformational Coupling in Mitochondrial Complex I,” Science Express, published Online July 1, 2010, Science DOI: 10.1126/science.1191046.
Isn’t this wonderful information? Now we see that the respiratory transport chain in mitochondria includes coupling rods that act like little locomotives. Those rods must be moving incredibly fast. They are pumping protons like gangbusters, 24×7, all the years of your life. This mechanical wonder is only one amazing device in the first stage of a respiratory chain that includes some 40 enzymes. The machinery dazzles and boggles the mind as it continues on its way to the climax of ATP synthase, one of the most elegant and perfect molecular machines ever discovered (05/25/2009).
Over and over again, we find researchers ignoring Darwinism as they uncover the workings of molecular machines in the cell. Darwin himself could never have imagined that life at its foundations would be this complex, this mechanical. It has all the appearance of Paley’s pocket watch – only more elegant, more efficient, and more beautiful at an unimaginably small scale. And this is just one of thousands of such machines. Remember the other locomotives, the machines that transport cargo down your molecular railroad? (See 02/25/2005 and 02/13/2003).
Darwinism is dying the death of a thousand “nano-mechanical principles.” The Darwinians who wished to abolish design thinking from biology and conjure up life by undirected chance and time should silently slink away. Grand mythic scenarios of impersonal emergence are so 19th century. Biology now needs engineers who appreciate intelligent design. (Notice how scientists in a recent paper in PNAS employed “engineering models to understand the control principles” of a biological phenomenon.) Fire the storytellers! Train engineers! (Catch the pun?) When science discovers powered locomotives at work in the simplest organisms, it no longer needs storytellers with loco motives.