When one considers receptor interactions with substrate and the chemical environment of a cell in general, one should keep in mind that a macroscopic view of these processes may not fully describe what is actually going on on a cell’s surface.
For example, let’s consider the rain. The process of rain from a meteorological perspective is explained by the condensation of water vapors in the upper or lower layers of the atmosphere, with the force of gravity subsequently acting on the vapors, condensed intro drops, making them fall down to earth. However, this view describes little of the experience of the rain for those who are witnessing it on the ground, for whom the multitude of drops appears, as a poet put it, as “dewy locks.”
The process of a cell’s interaction with its chemical environment can be seen through this analogy. More than just chemicals – it’s also a physical process, since, at this scale, a molecule is perceived as an electromagnetic field, and the process of interaction between the substrate and its receptor being perhaps akin to the experience of the rain for a typical human observer, since the presence of the substrate may be perceived by the receptor as a multitude of electric impulses.
This is, essentially, an example of “self-identification” as a method of cognition, expounded upon in certain esoteric and metaphysical teachings teaching, such as some of the yogic tradition. In this regard, here the cell may be perceived as a “planet,” while the receptor is some kind of an entity, such as a human; and the interactions of the latter with the substrate are experienced as “rain.” That is, we perceive the existence of the two “worlds,” surrounding the primary object of cognition, as the ones immediately “above” and “below” it.
While this is hardly science, this method may help one to understand the relationship of the receptor to the cell and its surrounding environment.