This may sound odd to some to people, but over the years of cellular study, I have developed several favorite cell structures. The reason for my favoritism lies in the complexity of these structures and how they stand as firm testimonies to an infinite all knowing Creator God. On that list of cellular favorites are the hundreds of membrane bound proteins, the cells second language (to be discussed later) and lastly the flagellar motor. Today we will look at that marvelous mechanical motor that operates the flagellum of the cell.
There has been quite a bit written about the flagellar motor and its complexity by both creationists and evolutionists. Creationists use it as a prime example of irreducible complexity that testifies to the wonder of our Creator God and evolutionists have tried their best to undermine the creationist’s claims. What I intend to do today is to lay out the basic workings of the flagellar motor and let you decide if it could have evolved by random chance or is a testimony to God’s creative hand.
Many different cells have some type of flagellum – a long thin extension of the cell that helps in cellular movement. For our purposes we are going to look at the flagellum of the bacterium E. coli since it has been the object of a great deal of the studies conducted on flagellar motors.
The movement of the flagellum is due to a motor assembly within the cell membrane. That motor assembly consists of a rotor, stator, bearing, drive shaft, universal joint (hook) and bushing that guides the driveshaft out through the cell wall.
Unlike the electrical motors we are familiar with that operate using a negative current flow of electrons, the flagellar motor operates by using a positive current flow generated by hydrogen ions also known as protons (H+). The proton current is generated by a pH gradient that that draws the protons from outside to inside the cell. For those environments that are low in hydrogen ions, the gradient flow other ions such as sodium (Na+) are used.
The bacteria take in food. As the food is oxidizes, it creates the proton flow which in turn causes one of the stator proteins to change shape. The misshapen stator protein then exerts a force against one of the rotor proteins which in turn drives the rotor assembly and spins the driveshaft of the flagellum.
When the bacterium needs to stop moving, it has a molecular clutch that disengages the motor from the filament driveshaft. Bacteria can reverse its direction of movement by simply reversing the rotation of the rotor which can be accomplished in as little as a ¼ turn of the driveshaft.
The bane of engineers and mechanics over the past few centuries is how to reduce friction wear and heat created when parts of a motor move against each other. In automobiles, we use motor oil to reduce friction wear and water and radiator coolant along with a fan to remove the excess heat produced by the engine parts. Regardless of what type of man made motor and cooling method used, a significant amount of energy is lost in the transfer of heat and friction. However, using the fluids of the cell which are mostly water, the flagellar motor operates at an extremely high rate of efficiency with negligible friction wear or heat, even at speeds up to 100,000 rpm. To date, no man made motor comes close to the efficiency level at which the flagellar motor operates.
Lastly, the flagellar motor is a self assembled system within the cell and has its own built in repair system if needed. It also has a hard-wired signal transduction system with a short term memory to operate the motor.
Look at the diagram of the flagellar motor parts and assembly. If any one of those parts were missing, the motor would not work, the flagellum would not move and the cell or bacterium would find itself stationary and unable to search for food or carry out its other functions. This is a classic example of irreducible complexity – something that is complex and yet reduced down to the fewest parts possible and still be able to operate. For this mechanism to work, all of the parts have to be in place at the same time. What is the probability that a lowly bacterium could evolve a donut shaped set of proteins to form the rotor and stator, along with the bushing, the hook that serves as a universal joint and the filament and all properly located in the right places in the cell membrane all at the same time? Evolutionists try to argue that the parts evolved one by one over time, but what purpose would a single part have by itself? If the cell is evolving functionless parts, they can only serve to add extra burden and require extra energy to produce and maintain without getting any benefit in return. And according to their survival of the fittest scenario, why would a cell replicate and pass on useless burdensome structures on to the next generation when a healthier and less burdened cell would be better fit to replicate and survive?
Once again we conclude an installment of the so-called simple cell series, by showing that it is anything but simple. The more you understand just how complex the cell is, the more we realize how improbable and impossible it is to explain how cells evolved in the first place. And if you can’t have that first cell evolve, the entire belief in biological evolution totally collapses, leaving only one logical and workable explanation for the origin of the cell and all of life. Our Creator God did just what He told us He did in Genesis 1 when He created the earth and everything upon it, especially the not-so-simple cell.