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(Excepted from our series “The New Scientific Evidence that Points to the Existence of God – Part 2.” Edited for publication. See our online store to order this entire series.)
(Continued from Part 1)
The Myth of the Simple Cell
Dr. Stephen Meyer: The whole question of the origin of life is a profound mystery; it was in Darwin’s time. But in Darwin’s time, people didn’t worry about it, because they thought the cell was so simple. They thought that a few simple chemical reactions would produce this substance they called protoplasm. And then, since that was the essence of life, a little enclosure around the protoplasm, and voila, we’ve got life. So they didn’t worry too much about it. But as we’ve discovered more about what’s actually inside cells, about the complexity of the simplest living unit of life, we’ve discovered that the simple cell isn’t simple at all.
Molecular Machines: The Bacterial Flagellum
The first class of evidence concerns what are called molecular machines, nanomachines, little tiny miniature machines that perform crucial functions either inside cells, or in this case in the cell membrane.
Dr. John Ankerberg: Yes. Let me stop you right here. First of all, in everybody’s body, there are trillions of cells. And in every cell you can find little machines. Now, you’ve never seen them, but the fact is, with the new technology that we’ve got today, you guys have seen these. But what blows your mind about this?
Dr. Stephen Meyer: Well, this is a particular miniature machine called a bacterial flagellar motor. It’s been made famous by my colleague Michael Behe, who is a biochemist at Lehigh University, in his book, Darwin’s Black Box. But lots of biochemists know about these machines.
Dr. John Ankerberg: What does it do?
Dr. Stephen Meyer: Well, it has a rotor, a stator, a U-joint, a drive shaft, and a whip-like tail that functions like a propeller. And it sits in the cell membrane there, the membrane of a one-celled bacterium, and it spins at, in some species, up to 100,000 rpm; can reverse direction on a quarter of a turn; and it’s hardwired into what’s called a signal transduction circuit that allows the little one-celled organism to detect where its food supply is. And it can detect changes in the sugar gradient in the aqueous solution in which it lives, and it motors around to find the best, you know, the best feeding grounds. And it’s a true rotary engine.
Kinesin Motors and ATP Synthase
And there are many other molecular machines that have been discovered. We have little walking robotic motor proteins that tow vesicles of material to where they’re needed for constructing things inside cells. It’s called a kinesin walking motor protein. There are turbines, a molecular machine called an ATP synthase that is a true turbine. There are little sliding clamps that are involved in DNA replication. So, there are multiple miniature machines at work in either one-celled organisms or in the cells in our bodies as well. And this has been a major discovery of modern microbiology and biochemistry in the last half century. And that, for one thing, shows that the cell is not simple at all.
The Complexity of Proteins and Amino Acids
Dr. John Ankerberg: But, Stephen, you argue that there are even more fascinating discoveries of what it takes to build machines like this inside the cells. Tell us about this.
Dr. Stephen Meyer: Yes, absolutely. If you look at that flagellar motor again, the little rotary engine we were talking about, and look at the different parts, there’s one we could call the universal joint. That universal joint is actually a protein. In fact, all the different parts of the flagellar motor and all the other molecular machines we’ve been talking about, are made of proteins. And proteins, in turn, are made of smaller subunits called amino acids. And I have a little illustration of that, that shows that the amino acids can be represented as different types of beads that link together. There are 20 different types of these amino acids, and they kind of functional like alphabetic letters. And if you get the letters in the right sequence, then this big chain will fold into a very specific shape. In one case, it may make a U-joint; in another case it may make the drive shaft; etc.
The Principle of Specificity
Dr. John Ankerberg: And that’s very important. If they don’t, it won’t function the way it’s supposed to.
Dr. Stephen Meyer: Exactly. So, it’s sequence specific. The arrangement of the parts has got to be very precise for the function of the whole. Now, proteins not only build parts for molecular machines, they also build, for example, enzymes which are crucial to the function of our cells.
And so, the principle of functionality for proteins is the three-dimensional specificity of fit. It’s a hand-in-glove; every protein has a very specific, three-dimensional shape that allows it to do its specific job. And it only gets that three-dimensional shape if the amino acids are arranged properly in this long, one-dimensional array so that they fold into the right shape.
Dr. John Ankerberg: With all kinds of different information that have to be arranged exactly right or it doesn’t work.
Dr. Stephen Meyer: Exactly. The principle is of specificity: specificity of arrangement; specificity of shape.
(Discussion will continue in Part 3)
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