Thursday, December 11, 2014

Potassium Channels Even More Clever Than Thought

What Was Thought to be the Problem is Actually the Solution

At the cellular level our bodies depend on a delicate balance of ions that is constantly adjusted. Potassium ions, for example, are atoms with one missing electron which are constantly streaming into or out of our cells. These positively charged ions enter and exit the cell via huge protein machines called channels which are imbedded in the cell wall and, like a donut, have a hole in the middle through which the ions flow. What is astonishing is how well these channels work. Not only do they open and close as needed, but they have two seemingly impossible design features. On the one hand they are extremely selective, allowing only a particular type of ion to flow through it. But on the other hand, they allow the chosen ions to flow through incredibly fast. It would seem that high selectivity would come at the cost of a slow transmission rate. But no, potassium channels for instance filter out practically everything but potassium ions, and yet their flow rate is practically at the maximum speed that is physically attainable. Now a recent study has added more information about how potassium channels perform their amazing feats.

One of the conundrums with ion channels is how ions of like charge, which therefore repulse each other, could be stuffed through the small hole in the ion channel protein machine. One possible answer is that the ions are separated from each other. For more than a decade now it has been thought that the potassium ions flowing through potassium channels are separated by water molecules. This would avoid the problem that the positively charged potassium ions repel each other, not making for a very smooth or concentrated flow.

The new study, however, persuasively argues that, in fact, the potassium ions travel together, not separated by water molecules. This higher concentration of potassium ions is achieved with a subtle, complex design of the charge contour within the channel. In fact, as the paper explains, the “repulsion between adjacent ions is found to be the key to high-efficiency K+ conduction.”

That's incredible, and this poses a problem for the theory of evolution because it means that random mutations, rather than forming a gene that produces some simple, easily formed molecular donut, instead must have discovered an astronomically unlikely design. Final causes and teleology which are so much despised by evolutionists are clearly the better explanation for the potassium channel. No that doesn’t mean science comes to an end, no that is not a religious explanation, and no that isn’t the final word in the matter. That is just what the science is telling us, loud and clear.


  1. Dr. Hunter, thanks for posting again.

    I have very little knowledge of the potassium ion channel things. I have responded to your post by googling a bit, but I am still unclear. It does seem clear that there are a number of different ions, not just potassium, that go through matching channels.

    Are these a phenomenon of eukaryotes, or does it exist in bacteria as well?

    Are all known ion channels similarly efficient?

    Is there any evidence that along one node of the "tree" potassium channels work one way, and on another node they work another way?

  2. Oh yes, several different ions are important, and as for the channels, that is yet another story. There are entire books devoted simply to documenting all the different variations on the channels. And no, they are by no means restricted to eukaryotes. Regarding efficiency, etc, again, there is a large diversity with different selectivities, efficiency, etc. So no, not all known ion channels are similarly efficient. But there is no scientific explanation for how these channels could have evolved. In fact, there is no such explanation for far simpler proteins.

  3. Amazing. Figure 3 in the original article is especially astonishing. A constantly changing 'charge contour' created by raising the energy level of electrons in each ion, then allowing it to fall at the right moment.

    What's not stated in the article is HOW these changes are induced by the structure. I can't tell if that's obvious to the authors or yet to be researched.

  4. Final causes and teleology which are so much despised by evolutionists are clearly the better explanation for the potassium channel.

    In what way is a final cause an explanation?

    What is the final cause of the potassium channel?

  5. Did you want that in terms of wave functions, or the grand canonical ensemble?

    1. You made the claim. I thought you might have the intellectual ability and force of character to support it.

    2. Wow... 0 to personal in 4 sentences. As soon as you go personal, you show you have an axe to grind rather than an interest in science. Fine. The only appropriate answer, then, is no answer. Taunting is bullying.

    3. Pedant:

      You made the claim. I thought you might have the intellectual ability and force of character to support it.

      Your first question was:

      In what way is a final cause an explanation?

      Final causes are future conditions, entities, or events regarded as the cause of the thing in question. Or, an event's final cause is the aim or purpose being served by it.

      Thus to acknowledge a final cause as an explanation for the origin of the potassium channel is to acknowledge that the channel's role, purpose, function, etc., could have driven its creation process. Just as when a craftsman builds a piece of furniture, he is not doing it blindly. The furniture's function and purpose is driving his work in creating it. That explains why he uses a tool in a certain way, in a certain place, at a certain time as opposed to "Gee, that was lucky."

      Now my question for you: How do evolution's astronomically unlikely explanations help science?

      What is the final cause of the potassium channel?

      It's incredible performance of allowing potassium ions pass through the membrane at the maximum speed that is physically attainable and yet with incredibly high selectivity, filtering out other types of ions.