What is Life? How Chemistry Becomes Biology
A review of What is Life? How Chemistry Becomes Biology by Rob Mason
All living beings are made up of cells. Some of them are made up of only one cell and others have many cells. The adult human body is estimated to contain from between 35 to 75 trillion cells. Cells are too small to be seen without magnification and range in size from 1 to 100 micrometers (0.0001 centimetre) The study of cells, also called cell biology, would not have been possible without the invention of the microscope. Cells contain DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), the genetic information necessary for directing cellular activities. Some cells carry oxygen to parts of our body. Other cells defend against invading bacteria and viruses. Cells also make other cells in a process called cell division.
Question raised in the first chapter of "What is Life? How Chemistry Becomes Biology" by Addy Pross
“Cells are made up of atoms grouped into molecules, which are collections of atoms. Atoms are much smaller than cells. In many ways the cell operates like a miniature factory one millionth of a millimetre in length. The factory involves a highly complex but integrated network of chemical reactions which extract energy from the environment and store it in a number of different chemical forms for use in the biosynthesis of essential cellular building blocks.
How is the complexity of the cell maintained, how did it come into being? Living cells are able to maintain structural integrity and organisation through the continual utilization of energy. That is why we have to eat regularly to survive.”
On page 8 of the first chapter the question of Darwinian evolution is raised and it is commented that while evolution explains how a single cell organism eventually becomes a whale or a human, it does not explain how the single cell was able to come into being. In other words how did a system capable of evolving come about in the first place? It is then pointed out that Darwinian theory is a biological theory whereas the origin of life problem is a chemical problem. Addy Pross believes that it is unlikely that such a complex system could have evolved by chance. A further point is made about life's purposeful character - all living things behave as though they have an agenda. Every living thing immediately and quite naturally gets on with it's particular purpose of living. In the non-living world, by comparison, understanding and prediction are achieved on the basis of quite different principles. You mix some chemical compounds together on the basis of whether they will react and what materials are likely to to form. You consider and apply the appropriate chemical rules depending on the nature of the problem and then come up with a prediction. No purpose, no agenda just inviolate laws of nature.
Chapter two: The Quest for the Theory of Life: raises the question of teleology: the doctrine (as in vitalism) that ends are immanent in nature. The theories of Aristotle are briefly mentioned particularly his view that the process by which life is generated and maintained indicates them to be goal directed. However during the 16th century that theory was replaced by the view that nature is objective and there is no underlying purpose to the natural order.
Charles Darwin’s book “The Origin of the Species” is cited as providing natural selection as a purposeful design in living systems. However it was later considered that Darwinian theory did not explain the origin of the primitive organism and consequently the central question of how life emerged – how design, function and purpose were generated and incorporated into non-living matter remained unresolved.
Chapter two concludes on the basis that the ‘What is Life’ riddle remains unresolved.
Chapter eight: One question that is made about living systems is how can one synthesize (duplicate) a living system? It is explained that it is easy to transform living systems into non-living ones but as is well known the process is not reversible – life is easy to destroy, but (chemically speaking) so hard to make. That simple fact in itself is highly informative. The problem with synthesis of a living system is not one of material but one of organisation. You can have all the components of a living cell available, but packaging it so that it behaves as a living entity is where the difficulty lies. So what is the problem? Life is a dynamic state of matter meaning that the biomolecules that make up the living cell are in a constant state of flux. A simple physical analogy that captures this dynamic character would be that of a juggler juggling several balls. That dynamic state is of course identical in a material sense to the one in which a man stands next to those balls, which are resting on the ground. But the difference is profound. How easy it is to take a juggler juggling several balls and to convert him into a non-juggling state, one in which all the balls are lying on the ground. A hefty push and you are there! A man standing next to five balls would be the metaphor for death. Of course going in the other direction is not that simple. You cannot simply throw five balls in one go at a person and expect him to enter the juggling state. That won’t work. In the same way, if you take all the components of a living cell and mix them together you won’t end up with a living cell. At very best, if all the bits and pieces end up in the right place, you’ll end up with a dead cell, a clump of stuff.
Also mentioned in chapeter 8 is the dynamic nature of life.
One of life’ striking characteristics is its dynamic nature. We commented that within the space of some months you are no longer who you were. Materially you are now composed of new stuff – a new you! Your blood cells, billions of them are replaced daily. Your skin continually turns over , the protein molecules that do most of the work in getting on with life are all continually being degraded in a never ending dynamic process.
A You Tube presentation by Cristen Conger