– Regulation of metabolic events within particular compartment (cellular organelle) that depends
only on interactions between molecules in the  compartment;

– regulations that occur within complete cells without any regard to extracellular signals, in
which proteosynthesis and transport across membranes that separate individual compartments have the
important roles have;

– regulations that are consequences of communication between cells in particular tissues, organs,
or the whole organism, depending on extracellular signals – neurotransmitters, hormones, cytokines,
and other  signal molecules.



















– Reversible covalent modification of proteins:

Reversible phosphorylation of proteins

Examples of protein kinases (PKs):







                         Hierarchical arrangement and signal amplification
                                   of some regulatory processes







Main types of membrane receptors







                              Selected types of G protein -subunits

Hormone receptors that activate G[s] or G[i] proteins
stimulates or inhibit adenylate cyclase