Enzymes
Enzymes are a sub category of proteins.
As biological catalysts (materials that can start or speed up a reaction, without itself being used as fuel) they are part of almost all metabolic
processes in a living cell. That is how they are responsible for the replication of DNA, for example. Enzymes digest sugars, fats and proteins in
bacteria, plants, and animals or in people. They also help us to fight against poisons or illnesses and to supply our cells with oxygen. In short,
enzymes are essential parts of all life.
Enzymes have many industrial uses as well. Made from bacteria, they can, for example, split corn starch into glucose as part creation of bio-ethanol, soften fruit for juicing or reduce the temperature change of chemical reactions to save unbelievable amounts of energy.
But what are enzymes on the genetic level?
An enzyme is made of amino acids that are compiled in long chains. There are 20 canon amino acids. The size of different enzymes can vary from 100 up to 30,000 amino acids. The function of an enzyme depends on the combination of amino acids. This information about a protein is saved in the DNA in the form of a gene and can be copied to a mRNA molecule (a portable copy of DNA) when needed and used as a matrix for the synthesis of new enzymes. This synthesis takes place in the ribosomes, which are the “protein factories” of a cell. The ribosome ‘knows’
which amino acids need to be attached based on the differing triplets (three connected bases = codons) on the mRNA strand. The mRNA molecule is clamped between the two subsections of the ribosome, one triplet after the other is read and the amino acid chain is extended piece by piece until the protein is structured, folded and able to take on its duties.
An example
As has already been outlined, enzymes protect against the influence of poisons. One of these poisons that has a great influence on humans but still continually makes it into the body is ethanol - better known as alcohol. When alcohol makes its way into the bloodstream
and liver, the entire body reacts by producing an enzyme (Alcohol dehydrogenase) that reduces ethanol to harmless material. The exact chain of events in the transformation of ethanol is the following: Two hydrogen atoms are separated from the ethanol molecule and a much less hazardous material (acetaldehyde) is produced. The body can then use it for further molecular transformations or dispose of it entirely. Every molecule has a so called "activity center", a small recess in the protein surface, where the catalytic reaction is carried out via the mitigation of "activation energy".
Picture: the 20 canon amino acids
Table: Amino acids with abbreviations an the corresponding codons