The notions of biology and biochemistry presented in this article as well as in the reviews [PHA 1 510], [PHA 1 512] et [PHA 1 516] involve many enzymes essential to understanding the functioning of living organisms.
After having approached the principal families of viral and bacterial enzymes, this article envisages the study of the biological catalysts which govern the life at the human being, a multicellular model taken as an example. The objective pursued is to try to understand the functioning of a eukaryotic cell in the middle of the 1013 others of its congeners and even more numerous prokaryotic cells and acellular structures in this type of organism.
The life of a complex multicellular organism involves many interactions. The first is that which is exercised between the organism and the external environment thanks to the nervous system, the endocrine system, the reproductive systems and the sensory organs. The second is that which takes place at the level of the exchange apparatus in relation to the cardiovascular system to nourish the cells of the organism (respiratory and digestive apparatus) and to eliminate waste (digestive apparatus, urinary apparatus, respiratory apparatus , cutaneous system). The last interactions are those which take place between the eukaryotic cell and the interstitial lymph in which it bathes, as well as the interactions within the cell.
At the level of eukaryotic cells, many compartments are organized with well-defined functions. They therefore have specific enzymatic contents within them. As an apparatus or a system has its organs, the eukaryotic cell has its own organelles.
The cells of eukaryotic organisms are therefore very well structured. There are specific compartments dedicated to precise cellular functions, that is to say to the progress of chemical reactions controlled in space and time.
In this article, the different enzymes presented will be linked to the compartment where they perform their function: the catalyzed chemical reaction.
Among more than 200 types of specialized cells found in a human being, a few examples will be cited in order to study the enzymatic productions according to a given cell type.
At the end of the article, the reader will find a glossary and a table of acronyms and notations used.