Toward a Biology Worthy of Life > The Unbearable Wholeness of Beings > Brief excerpt
A project by Stephen L. Talbott

Dead molecules or living processes? (2)

“But”, comes the reply, “all the molecules involved in these processes are made by DNA”.

That’s not true. First, as I just mentioned, DNA by itself cannot make anything. Second, many crucial molecules that shape the functioning of the cell, including all lipids and carbohydrates, do not derive from DNA. This reminds us that the central functioning of metabolism — the transformation of nutrients in the cell — is not in any realistic sense controlled by DNA. The reverse is just as true; metabolic processes send signals to DNA when its resources are wanted. Third, the proteins and noncoding RNAs that do derive from DNA are extensively and significantly modified by processes in the cytoplasm, with their functions depending heavily on these modifications. Fourth, the enzymes and other proteins essential for transcribing DNA certainly cannot be described as mere products of DNA because they are part of the essential means for producing all proteins, including themselves. And fifth, DNA, far from being responsible for everything in the cell, is itself the responsibility of the cell, which goes through a balletic drama of scarcely conceivable complexity in order to replicate and preserve this vitally important molecule.

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