Fundamentals of Biochemistry - Filippovich, Yu. B. 1999

Proteins

This section is the most crucial part of the course in biological chemistry, as Proteins play a paramount role both in building living matter and in driving vital metabolic processes.

Why are proteins the essential substrate of life? Because they possess A number of unique features that are absent in any other Organic compounds.

1. Giant protein molecules are distinguished by an inexhaustible diversity of Structure combined with strict Specificity for any given, specific protein.

2. Proteins are capable of intramolecular interactions, which ensure the structural dynamics of their molecules, the Variability and plasticity of their conformation, and the reversibility of transitions between globular and fibrillar states.

3. Featuring amino acid side chains with diverse chemical properties within their polypeptide chains, protein molecules as a whole and their individual domains can engage in various chemical and physical interactions both with each other and with Nucleic Acids, Polysaccharides, Lipids, etc., forming supramolecular complexes that constitute The basis of subcellular structures.

4. A critical feature of the mechanism underlying these complexes is the infallible mutual "recognition" of their components and the self-assembly-driven Nature of the association process itself.

5. Protein molecules systematically alter their structure in response to external stimuli and restore their initial state upon removal of the stimulus, a phenomenon that can be coupled with energy acceptance and Transduction.

6. Many proteins possess The unique ability to catalytically accelerate Chemical Reactions occurring in living matter.

7. Proteins perform regulatory, protective, toxic, transport, contractile, structural, receptor, modulatory, morphogenetic, storage, and many other Functions.

Even this far-from-exhaustive list of properties that set proteins apart from other natural Biopolymers highlights their critical role in supporting the fundamental attributes of life.

Only through a detailed study of protein Structure and properties can one fully understand both their aforementioned characteristics and their functions; therefore, the biochemistry course traditionally begins with the section on proteins.