Cells use molecular vehicles that carry cargo on networks of “highways.” Some scientists can’t avoid the comparison to modern vehicular traffic. Brookhaven National Laboratory reports:
Molecular motor proteins inside the body, called kinesins, are a lot like the motor in your car. The molecular motors convert stored chemical energy into specific conformational changes, which lead to various movements in cells, analogous to the way a car engine converts the energy of gasoline combustion into torque generation, which leads to tires rotating on an axle. (Emphasis added.)
The analogy proceeds seamlessly into a discussion of how Dartmouth College researchers have succeeded in tweaking the kinesin motor by adding a “switch” to “to control the activity of these organic nanomotors.” Kinesins don’t come with an “ignition switch,” so the researchers exchanged a magnesium atom for manganese, giving them the ability to stop and start the kinesin engine:
“Now we have the ability to tightly control the speed of these motors, such that we can ‘turn them off’ and ‘turn them back on’ similar to a dimmer switch on your lights at home,” said Jared Cochran, who worked with a team to devise the control “switch” for kinesin motors. They found that in the presence of magnesium, the engineered enzyme stops functioning. But introduce manganese, and it will jumpstart the motor protein again.
Their ignition switch thus includes the function of a pedal to control the speed. Cochran explains, “One can simply vary the ratio of magnesium and manganese ions, which in turn can modulate the target enzyme activity from inactive to wild-type levels.” Mechanics will appreciate the analogy to gear ratios.
The metal “switch” is a valuable tool that can help researchers studying energy conversion in enzymes. This method also allows researchers to study sub steps of the kinetic cycle, stopping the reaction at particular steps in the cycle, which can be tricky to isolate.
Let’s get this straight. The researchers recognized these protein machines as performing functions analogous to automobile engines. Even though cars and trucks are orders of magnitude larger, the functions are the same: ignition, energy conversion, controlled movement.
No one questions the intelligence of the researchers whose design, purpose and action were “geared” to taking existing cell machinery and modify it so that they could understand it. Why, then, attribute the original machinery to blind, purposeless evolutionary processes? You don’t tweak a rock to make it work better. If kinesin has a function analogous to that of a car engine, the intelligent design of the car engine is equally analogous to the intelligent design of the cellular machine.
The news from Brookhaven says nothing about evolution, showing once again that evolutionary theory is superfluous to much biological research, despite Dobzhansky’s claim that nothing in biology makes sense without it. On the contrary: nothing about molecular machines makes sense without intelligent design.