What is life?

Well, life is what you make it. As a biologist (or a scientifically-minded person for lack of proper terminology), I believe that there are certain criteria that life falls into. For example, a tree is alive. As conscious beings, we cannot communicate with a tree, nor can we sympathize with its style of life since it is a stationary object. However, trees have just as many chemical processes occurring within their trunks, branches, stems and leaves as humans do in their entire bodies. They require an intricate balance of chemical support, water, and sunlight. They are also able to reproduce with or without a mate (depending on the species of tree and the environmental stressors at the time of reproduction). When all of these processes stop, the tree begins to decay. This indicates that all of the processes in the aforementioned have ceased; the tree has reached a state of equilibrium. In terms of life, equilibrium equals death. When the chemical membranes of any organism reach a state in which there is no longer a gradient of any kind, or any chemical exchange occurring, the organism is no longer viable. Life ceases, and the chemical byproducts of the extinguished reaction then return to the place from which they came: the earth. On a much smaller level, viruses and prions are debatably alive. It is difficult for us as humans to decide whether these minute, yet complex things are actually alive or not. From our own experience, life entails consciousness. These terms, however, cannot be applied to this biological debate. For example: a person can be brain dead but can still be considered technically alive due to the fact that their body has not yet reached equilibrium. These people are (probably) not aware of the world around them, and would die without constant medical attention, but they are still alive while unconscious. The world of microorganisms is an unconscious one, driven by active and passive chemical processes that drive them to eat, rest, reproduce, attack other microorganisms and defend themselves from attack. Chances are bacterium, protozoans, fungi, viruses, and prions are not conscious. This lack consciousness, intelligence, and mammalian "feeling" does not exclude them from being classified as alive. The main exception to this argument is prions, since their existence is in the form of a functional protein; a chemical molecule with no appendages, no membranes, no organelles, and no DNA or RNA. They are driven by the simplest intermolecular forces that allow molecules to join together and change the shape, and thus the functionality, of any other molecule they come in contact with. How they reproduce is a mystery to me (due to the fact that I have not reached the level of biochemistry yet). All that I am certain of is that prions are molecules that replicate themselves. There are thousands of other examples of this in the biological world. Enzymes have the capacity to do this. So do some forms of mRNA. This lack of exclusivity leads me to believe that prions are not alive, although they may share some of the quintessential properties of life that other living things may exhibit.