Essential reactions too slow for life, according to a report in Biology News Net, 11 Nov 2008. Most chemical reactions inside living cells are controlled by enzymes that speed up the rate of reactions. Without the enzymes the reactions would not occur fast enough to sustain life. Richard Wolfenden, a biochemist at the University of North Carolina at Chapel Hill, has been studying chemical reactions that are essential to life to see how they would work without the enzymes. In 1995 he worked out that a reaction absolutely necessary for making DNA and RNA would take 78 million years without the enzyme that makes it happen in living cells.

Now he and a colleague have "found a reaction that - again, in the absence of an enzyme - is almost 30 times slower than that. Its half-life - the time it takes for half the substance to be consumed - is 2.3 billion years, about half the age of the Earth. Enzymes can make that reaction happen in milliseconds." The reaction is essential for making chlorophyll and haemoglobin (green pigment in plants, red pigment in blood). Wolfenden commented: "This enzyme is essential for both plant and animal life on the planet. What we're defining here is what evolution had to overcome, that the enzyme is surmounting a tremendous obstacle, a reaction half-life of 2.3 billion years."

Understanding how chemical reactions and their enzymes work is important for developing new medicinal drugs, but man-made enzymes are a long way off, according to Wolfenden. He commented: "We've only begun to understand how to speed up reactions with chemical catalysts, and no one has even come within shouting distance of producing, or predicting the magnitude of, their catalytic power."

Biology News Net

Editorial Comment: The enzyme required for this reaction is only one of thousands necessary to make the simplest cell function. Even if most of these reactions don't have a natural reaction time nearly as slow as the one described above, they are far too slow to make life without enzymes to speed them up.

Enzymes are large complex proteins, made by linking many hundreds of amino acids that must be put together in a specific sequence. This only happens in cells because information from DNA is used to determine which amino acids goes in which place in the chain. Furthermore, chemical reactions in cells do not occur in isolation. They work in complex series of reactions, which must work in the correct sequence and have their rates coordinated. This often involves other chemicals called co-enzymes that must be in the right place at the right time.

Altogether, it requires the most enormous faith in something we have never seen happen to believe that a living cell could form itself from uncontrolled chemical reactions. It also requires faith to believe that living cells were created, but this is a rational faith, because we have seen reaction controlling catalysts created by intelligent scientists. Therefore, it is reasonable to believe the more efficient catalysts in living cells were designed and made by a much smarter biochemist. (Ref. Time, biochemistry, biosynthesis)

Evidence News 12 December 2008


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