> [!summary] Progressive Summary # Structured Notes ## Definitions ## Chapter Summaries Enzymes are important catalysts for biological processes, and they need minerals. For instance, carbonic anhydrase, which helps transport carbond dioxide to and from a cell's environment, needs zinc for its formation. In the early days of life on the planet, these trace elements would be drawn from the environmental bank, but over time they would become rarer as they are used up. When organisms die, they bring these precious elements to the bottom of the oceans. Life would have evolved scavengers to harvest these elements before they were buried. > In our own society since the Industrial Revolution we have encountered major chemical problems of shortages of essential materials and of local pollution. The early biosphere must have been faced with similar problems. Perhaps the first ingenious cellular system which learned to gather zinc from its environment, at first for its own benefit and then for the common good, also unwittingly garnered the similar but poisonous element, mercury. Some slip-up of this nature probably led to one of the world's first pollution incidents. As usual, this particular problem was solved by natural selection, since we now have systems of micro-organisms which can convert mercury and other poisonous elements to their volatile methyl derivatives. These oganisms may represent life's most ancient process for the disposal of waste. > > Pollution is not, as we are so often told, a product of moral turpitude. It is an inevitable consequence of life at work. The second law of thermodynamics clearly states that the low entropy and intricate, dynamic organization of a living system can only function through the excretion of low-grade products and low-grade energy to the environment. Criticism is only justified if we fail to find neat and satisfactory solutions which eliminate the problem while turning it to advantage. To grass, beetles, and even farmers, the cow's dung is not pollution but a valued gift. In a sensible world, industrial waste would not be banned but put to good use. The negative, unconstructive response of prohibition by law seems as idiotic as legislating against the emission of dung from cows. # Quotes