Question
I have heard that the second law of thermodynamics was that S (entropy)
>0, or in laymen's terms, says that things tend toward disorder. I was
trying to discuss this with a person who said they knew physics, and he
stated that the DNA molecule, or life, (and therefore evolution) didn't
fall under this law because energy input to the molecule makes the
theory not applicable.
Can you shed some light on his statement, ether explaining it or maybe
explaining what he was trying to say?
Thanks.
Bill
Answer
The second law applies to everything in the Universe (so far as we know), so your friend is incorrect that it doesn't apply to DNA.The energy organisms take in - either through food (the chemical reactions in digesting and processing food provide energy, not just material), light or some other means (e.g. heat) is what keeps life's engine's going. Like all things, without that influx of energy the processes (chemical reactions) that maintain an organisms function ("life") would cease. Then entropy ("death") does set in.At the molecular level (DNA, RNA, etc.) life is no different. Energy is required to move the bases around to line up with their partners during replication. Energy flows to make or break the bonds between base pairs during both the "zipping" and "unzipping" during that process. Energy is required for all that stuff that goes on inside a cell.If DNA and life were not subject to the second law, we (organisms) could exist without any energy input at all - plants could grow in the dark, animals wouldn't need to eat.Try telling your hungry tummy the second law doesn't apply! I think that it'll disagree with you - and eventually win the argument. http://vrd.askvrd.org/services/answerschema.xml
