Tuesday, December 12, 2006

`An enzyme ... is only a catalyst ... It cannot make anything happen that would not have happened, though more slowly in its absence' (Wald)

In further reducing my stack of unclassified photocopies, I rediscovered my photocopy of a famous 1954 Scientific American article on the origin of life by the late Harvard biologist and Nobel laureate George Wald (1906-1997)

[Graphic: Ribbon diagram of enzyme Orotidine monophosphate decarboxylase, aka OMP Decarboxylase, aka ODCase, Wikipedia]

In re-reading the article, I noticed this, where Wald mentioned something that was "more important than all the special processes ... for organic syntheses" and that was "the special class of proteins called enzymes ... which greatly accelerate chemical reactions" in biochemistry. However, since "enzymes themselves are proteins ... One is asking ... for an apparatus which is the unique property of cells in order to form the first cell." But Wald just assumes, without doing any calculations, that "Every process that is catalyzed by an enzyme ... would occur without the enzyme" with "The only difference is one of rate. .... What takes only a few moments in the presence of an enzyme or other catalyst may take days, months or years in its absence; but given time, the end result is the same":

"A final consideration, however, seems to me more important than all the special processes to which one might appeal for organic syntheses in inanimate nature. It has already been said that to have organic molecules one ordinarily needs organisms. The synthesis of organic substances, like almost everything else that happens in organisms, is governed by the special class of proteins called enzymes-the organic catalysts which greatly accelerate chemical reactions in the body. Since an enzyme is not used up but is returned at the end of the process, a small amount of enzyme can promote an enormous transformation of material. Enzymes play such a dominant role in the chemistry of life that it is exceedingly difficult to imagine the synthesis of living material without their help. This poses a dilemma, for enzymes themselves are proteins, and hence among the most complex organic components of the cell. One is asking, in effect, for an apparatus which is the unique property of cells in order to form the first cell. This is not, however, an insuperable difficulty. An enzyme, after all, is only a catalyst; it can do no more than change the rate of a chemical reaction. It cannot make anything happen that would not have happened, though more slowly' in its absence. Every process that is catalyzed by an enzyme, and every product of such. a process, would occur without the enzyme. The only difference is one of rate. Once again the essence of the argument is time. What takes only a few' moments in the presence of an enzyme or other catalyst may take days, months or years in its absence; but given time, the end result is the same." (Wald, G., "The Origin of Life," Scientific American, Vol. 191, No. 2, August 1954, pp.44-53, p.48. Emphasis original).

Paul Davies also states the chicken or egg dilemma of proteins (by which he means enzymes) which "have the job of catalyzing (greatly accelerating) key biochemical processes" without which "catalysis life would grind to a halt", yet "proteins are also made by nucleic acid"and "it is hard to see how a molecule like RNA or DNA ... could come into existence spontaneously if it was incapable, in the absence of proteins, of doing anything (in particular, of reproducing)" yet "it is equally unlikely that nucleic acid and proteins came into existence by accident at the same time and fortuitously discovered an efficient symbiotic relationship":

"Proteins have the job of catalyzing (greatly accelerating) key biochemical processes. Without this catalysis life would grind to a halt. Proteins perform their tasks under the instructions of nucleic acid, which contains the genetic information. But proteins are also made by nucleic acid. This suggests that nucleic acid came first. However, it is hard to see how a molecule like RNA or DNA, containing many thousands of carefully arranged atoms, could come into existence spontaneously if it was incapable, in the absence of proteins, of doing anything (in particular, of reproducing). But it is equally unlikely that nucleic acid and proteins came into existence by accident at the same time and fortuitously discovered an efficient symbiotic relationship. The high degree of improbability of the formation of life by accidental molecular shuffling has been compared by Fred Hoyle to a whirlwind passing through an aircraft factory and blowing scattered components into a functioning Boeing 747. It is easy to estimate the odds against random permutations of molecules assembling DNA. It is about 10^40,000 to one against! That is the same as tossing a coin and achieving heads roughly 130,000 times in a row." (Davies, P.C.W., "Are We Alone?: Philosophical Implications of the Discovery of Extraterrestrial Life," Penguin: London, 1995, pp.18-19).

And, getting back to Wald's claim that the same reactions would still occur without enzymes, except they would take longer, i.e. instead of "only a few moments in the presence of an enzyme" they would take "days, months or years in its absence," a senior professor of biochemistry named Dr. Richard Wolfenden did the calculations for "a biological transformation deemed `absolutely essential' in creating the building blocks of DNA and RNA" and it "would take 78 million years in water" and another enzyme whose "half-time - the time it takes for half the substance to be consumed - is 1 trillion years" which is "way beyond the known universe in terms of slowness"!:

"All biological reactions within human cells depend on enzymes. Their power as catalysts enables biological reactions to occur usually in milliseconds. But how slowly would these reactions proceed spontaneously, in the absence of enzymes - minutes, hours, days? And why even pose the question? One scientist who studies these issues is Dr. Richard Wolfenden, Alumni distinguished professor of biochemistry and biophysics and chemistry at the University of North Carolina at Chapel Hill and a member of the National Academy of Sciences. In 1998, he reported a biological transformation deemed `absolutely essential' in creating the building blocks of DNA and RNA would take 78 million years in water. [Williamson, D., "Researchers find structure of enzyme that catalyzes 78-million-year reaction," UNC-CH News Services, Feb. 22, 2000] `Now we've found one that's 10,000 times slower than that,' Wolfenden said. `Its half-time - the time it takes for half the substance to be consumed - is 1 trillion years, 100 times longer than the lifetime of the universe. Enzymes can make this reaction happen in 10 milliseconds.' Wolfenden, along with co-authors Chetan Lad and Nicholas H. Williams of Sheffield University in England, published a report of their new findings April 29 in the online `early edition' of the Proceedings of the National Academy of Sciences. .... The report highlights the catalytic power of phosphatase enzymes to tremendously enhance the transformation rate in water of a specific group of biochemicals: phosphate monoesters. Protein phosphatase enzymes acting on these monoesters help regulate the molecular cross-talk within human cells, the cell signaling pathways and biochemical switches involved in health and disease. `We have esters floating around in our cells with all kinds of functions,' Wolfenden said. `Every aspect of cell signaling follows the action of the type of phosphatase enzyme that breaks down phosphate monoesters. Other phosphatases highlighted in the study for their catalytic power help mobilize carbohydrates from animal starch and play a role in transmission of hormonal signals.' As to the uncatalyzed phosphate monoester reaction of 1 trillion years, `This number puts us way beyond the known universe in terms of slowness,' he said. `(The enzyme reaction) is 21 orders of magnitude faster than the uncatalyzed case. And the largest we knew about previously was 18. We've approached scales than nobody can grasp.' Why would we want to know the rate of a biological reaction in the absence of an enzyme? That information would allow biologists to appreciate what natural selection has accomplished over the millennia in the evolution of enzymes as prolific catalysts, Wolfenden said. It also would enable scientists to compare enzymes with artificial catalysts produced in the laboratory. `Without catalysts, there would be no life at all, from microbes to humans,' he said. `It makes you wonder how natural selection operated in such a way as to produce a protein that got off the ground as a primitive catalyst for such an extraordinarily slow reaction." (Lang, L.H., "Without enzyme catalyst, slowest known biological reaction takes 1 trillion years, EurekAlert!, 5 May, 2003).

While these are admittedly the slowest uncatalysed reactions, not the fastest, and while the "1 trillion years" reaction might not be essential to the origin of life, the "78 million years" OMP Decarboxylase reaction may be.

Note also the hold that the Darwinian naturalistic paradigm has on Dr Wolfenden. He has just effectively proved that "Without catalysts, there would be no life at all, from microbes to humans" (i.e. the first living organism would have had to have at least the minimal suite of highly complex enzymes needed to catalyze the biochemical reactions needed to survive and self-replicate, which includes producing copies of all those enzymes!), yet he assumes that somehow "natural selection operated in such a way as to produce a protein that got off the ground as a primitive catalyst for such an extraordinarily slow reaction"!

But there is no "natural selection" until there is life. As Theodosius Dobzhansky, co-founder of Neo-Darwinism pointed out, "In order to have natural selection, you have to have self-reproduction or self-replication and at least two distinct self-replicating units or entities" and therefore "Prebiological natural selection is a contradiction of terms":

"Dr. Schramm's introduction gives me an opening for making a few remarks on my own. Natural selection is sometimes described as a mechanism capable of realizing the highest degree of improbability, as Dr. Schramm has quite correctly pointed out. I would like, however, to express the belief that the words `natural selection' must be used carefully. Dr. Schramm has so used them. In reading some other literature on the origin of life, I am afraid that not all authors have used the term carefully. Natural selection is differential reproduction, organism perpetuation. In order to have natural selection, you have to have self-reproduction or self-replication and at least two distinct self-replicating units or entities. Now, I realize that when you speak of origin of life, you wish to discuss the probable embryonic stages, so to speak, of natural selection. What these embryonic stages will be is for you to decide. I would like to plead with you, simply, please realize you cannot use the words `natural selection' loosely. Prebiological natural selection is a contradiction of terms." (Dobzhansky, T.G., Discussion of "Synthesis of Nucleosides and Polynucleotides with Metaphoric Esters," by George Schramm, in Fox, S.W., ed., "The Origins of Prebiological Systems and of Their Molecular Matrices," Proceedings of a Conference Conducted at Wakulla Springs, Florida, Oct. 27-30, 1963, Academic Press: New York NY, 1965, pp.309-310).

Stephen E. Jones, BSc (Biol).


Genesis 26:2-5. 2The LORD appeared to Isaac and said, "Do not go down to Egypt; live in the land where I tell you to live. 3Stay in this land for a while, and I will be with you and will bless you. For to you and your descendants I will give all these lands and will confirm the oath I swore to your father Abraham. 4I will make your descendants as numerous as the stars in the sky and will give them all these lands, and through your offspring [seed] all nations on earth will be blessed, 5because Abraham obeyed me and kept my requirements, my commands, my decrees and my laws."

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