Biochemistry

Biochemistry was the term used to describe the complex chemistry on which most life was based.

Biochemistry arose from the complex chemistry of various substances interacting within a stable environment over a very long period of time. This environment was most commonly a planet, and Biochemistry most commonly developed within a liquid solvent.

The most essential property of a substance required to create biochemistry was catenation, the ability to form chains. Of all the elements, carbon was the most efficient at forming long chains. Thus, the majority of life was based on carbon.

The most common form of biochemistry was that based on carbon, nitrogen, oxygen and hydrogen. These elements formed the basis of amino acids, chemicals capable of forming long biochemical chains, which would eventually become systems of ever greater complexity, eventually giving rise to a lifeform. The most common liquid wherein biochemistry developed was water.

Despite this, there were various other types of biochemistry that did not fall into this category.

Superstructure element
The most common element to develop into a biochemical system was carbon. However, various elements were known to form the basis of biochemical systems. These included:
 * Carbon
 * Silicon
 * Boron
 * Phosphorus
 * Sulfur
 * Aluminium
 * Germanium

Replicator
One of the most important aspects of life was it's ability to generate it's structure based on genetic information. Various chemical substances were used to do this. They included:
 * Helical acids (double stranded, helical, hydrogen bound acidic polymers)
 * Proteins (based on amino-acid chemistry, various shapes)
 * Lipids (based on catenated structures mounting chains of different lengths)
 * Single catenated strands

Fuel
Heterotrophic lifeforms usually had to consume specific chemicals they could use to power themselves. The nature of these chemicals depended on their biochemistry. Common fuels included:
 * Carbohydrates and non-carbon equivalents. These were long chains of hexagonal chemical structures linked together
 * Lipids. These were based on central catenated chains with secondary chains as branches, and a few non catenating elements
 * Proteins
 * Alkanes
 * Acids and bases
 * Hydrogen gas and oxidizing agents
 * Radioactive substances
 * Hydrogen peroxide

Solvent
Solvents were the liquids in which biochemistry formed. The most common solvent was water, but there were numerous others:
 * Water
 * Ethanol
 * Ammonia
 * Methane
 * Alkane
 * Sulfuric Acid
 * Liquid metals
 * Cryogenic oxygen, nitrogen and argon.

Gas Exchange
Lifeforms were often involved in gas exchange with a planets atmosphere, and their biology was often heavily influenced by what gases were in the environment. These included:
 * Water
 * Oxygen
 * Carbon Dioxide
 * Hydrogen
 * Hydrogen Sulfide
 * Sulfur Dioxide
 * Chlorine
 * Ammonia
 * Methane

Motility
Many lifeforms required specialized chemical systems to allow them to move (muscles). These included:
 * Protein muscle
 * Helical acid muscle
 * Metallic muscle
 * Hydraulic muscle

Non chemical life
Not all life was based on chemistry. Some life was based on non-chemical phenomena. Droids were based on semiconductor electronics and mechanical motor systems. Some droids were able acquire their own power without sentient assistance, and also able to self replicate, leading some to consider them lifeforms in their own right.

Nuclear life was life based on the interactions of subatomic particles. It was extremely rare and did not occur naturally, as it generally required ligism and equilism.

Digital life was self sustaining, self replicating software that developed within vast computer systems.