A/N: Consequence of me trying to study for a microbiology exam with really bad timing (aka. in b/w anatomy and biochemistry) with a chem. exam the week before. So this is somewhat of a summary of physical chemistry, protein biochemistry and the origin of life from microbiology (and a tad from biochem). The lecturers should be happy about the integration. :) Of course, it does seem a little pointless just putting up an introduction, but *shrugs*.
The Order of Life
The majority of biologists believe the conditions in which life first began approximately 3.5* billion years ago are a replica of the environments contained within active volcanoes: hot, anoxic and with only the simple compounds of water, hydrogen, nitrogen, methane and ammonia available. Scientists as a collective believe the laws of thermodynamics as the laws that govern our universe. I for one have never come across an exception; after all, they are the binding principles of many of our physical and chemical theories today*. Energy is neither created nor destroyed*. The universe tends towards disorder*. A state of order can only be achieved at the temperature of absolute zero*. And yet…the leading theory regarding the origin of life on this planet asserts that the Earth began with a temperature well over that which permeates the globe today. Have we come closer to order? Or are we simply deluded by our ignorance? Or perhaps arrogance – it may be, after all, that the answer to life's question is not in fact 32* but the simple observation that a protein prefers to pack into a three-dimensional structure because it decreases the surface area available for bonding and thus increases the entropy* of the surroundings, making it a pinnacle of order in a sea of chaos.
* "3.5 billion years ago" - textbooks generally give a figure between 3.5 and 3.8 billion years ago. 3.5 is the ballpark figure
* "Energy is neither created nor destroyed" – first law of thermodynamics
* "The universe tends to disorder" – second law of thermodynamics
* absolute 0 = 0K = -273.15 degrees C. The temperature where all motion is said to cease and everything present as a perfect crystalline solid, aka. highest level of order. Third law of thermodynamics.
* 32 – no. of ATP molecules produced by aerobic respiration (except certain cells that only produce 30 – blood is NOT aerobic therefore only produces 2). Scientists call it the answer to life after all the trouble they went through to understand it wasn't 42 like they thought for years. Funny story actually.
* entropy – the measure of disorder in a system. More positive entropy means higher disorder. Actually, it's a measure of the number of states a particular molecule can occupy, but that's less relevant here. Unfavourable reactions (leading to order) are coupled with more favourable reactions with a higher value therefore the overall reaction becomes unfavourable. Otherwise we wouldn't be able to move.