Enzymes are crucial to all life.  They are defined as a protein molecule in a plant or animal that catalyzes specific reactions of metabolism without itself being altered permanently, or destroyed.  In other words, an enzyme is a protein that instigates a reaction, and never becomes part of the reaction.  A catalyst is that which changes the activation energy of a reaction to either increase, or decrease the speed of the reaction. An enzyme is a large protein molecule, many times larger in atomic mass than a water molecule.  There are thousands of different types of enzymes that initiate, accelerate, or separate the various chemical reactions in living cells.  They are each very selective in the reactions they create. Living cells are made up of a complex system of chemical reactions, all of which must take place at carefully controlled rates.

The chemical reaction catalyzed by an enzyme is done so at a very specific location within the molecule.  This is known as the active site, and the substances in which the reaction occurs is called the substrate.  The basic structure of this process can be clarified what is known as the ‘lock and key’ model.  The substrate (key) fits neatly into the enzyme (lock) to accommodate the chemical process, but only one kind of key can fit into the lock. Only one kind of substrate can fit into the active site of the enzyme.  The process under which the bonding of the substrate and enzyme take place is due to electrostatic forces involving a given molecule’s polar magnetic forces of positive and negative charges.  When the positive end of a molecule comes close to a negative end of another molecule, an attraction occurs.  If the key fits the lock, a bond occurs.  Enzyme activity can be diminished or destroyed if is some other molecule is able to bond to the active site and block the entry of the substrate.  These substances are known as enzyme inhibitors.

While more than a thousand different enzymes have been identified, they have been generally classified into six categories.  The “Oxyreductases” are enzymes that catalyze hydrogen transfer.  “Hydrolases” catalyze the transfer of water elements at a specific site in the molecule.  “Tranferases” catalyze the transfer of all non-hydrogen atoms.  “Lysases” contribute to many transport and regulatory processes involving metals, fatty acids, and harmones.  “Isomerases” catalyze reactions involving structural rearrangement of molecules.  “Ligases” work with DNA in catalyzing sugars and phosphates in cell replication.

Some of the commonly known enzymes used in agriculture and bio-remediation are Protease, Amylase, Cellulase, and Pectinase.  The micro-biological aspects of the soil system and subsequent plant growth process involve enormous quantities of micro-organisms, as discussed in other sections.  The micro-organisms produce, and rely upon the catalytic processes of enzymes, and are therefore reliant upon sufficient quantities of the enzymes to multiply and provide the necessary means for breaking down the nutrients for plant uptake.  In soil conditions where bacterium are limited, plant growth is inhibited.  This can be overcome by the addition of a properly balanced inoculation of an enzyme and bacteria package structured to balance the microbial community.