System: any part of the universe that is of interest to us -- as an engine, two people bonded in a relationship, one person's social network, the solar system, etc. Specifically, the region of universe under study. A system is separated from the remainder of the universe by a boundary which may be material or not, but which, by convention, delimits a finite volume. The possible exchanges of work, heat, or matter between the system and the surroundings take place across this boundary:
Supramolecular Receptor: macroscopically-speaking, any type of receiver as: a cell, a group of cells, or sensory organ that receives stimuli, generally known as the peripheral sensory system; or molecularly, a chemical group, molecule, or atom on the supramolecular surface that has an affinity for a specific chemical group, molecule, or fundamental particle energy (as a photon), etc., which function to absorb field particle inputs of either a direct or indirect character:
The shown human molecular formulas (above) are duplicate in presentation owing to the nature of the magnitude of each element shown in reduced form. Using more finite calculation techniques, each human molecule would be defined with each owns unique molecular formula.
Supra Human Molecular Organism: a bound state of three or more human molecules bonded into one collective structure as: a group, a school, a corporation, a town, a society, a political system, a country, etc., being characterized by such thermodynamic definers as: metabolism, efficiency, energy / mass balance, flow rate, structural integrity, etc.
"An economic system is a society of people bonded by social contract."
– Thermodynamic Researcher: Mae-Wan Ho 
“One can view people, companies or governments as single, coherent entities exerting influence on others.”
– Jeff Vail, A Theory of Power 
In the Haber process, ammonia (NH3) is synthesized over a sheet of iron (Fe) embedded with a few oxides of potassium (K). Through this reaction, a reaction analogous in principle to the typical human molecular chemical reaction or formation of the human molecular ‘couple’, we have the following steps:
First: gaseous hydrogen molecules (H2) and gaseous nitrogen molecules (N2), being somewhat evolutionary molecular ancestors to human molecules, touch down and 'attach' to the metal sheet (earth substrate is 33.7% iron by mass). This is similar to how a human molecule is born, then bonds to society, then attaches to a location (house) on surface of the substrate (earth) via a mortgage, typically.
Second: because of this attachment to the surface, kind of like a human molecule eating and raising his or herself to maturity, these ‘attached molecules’ modify themselves via atomic, molecular, photonic exchange with the surface.
Third: in their reactive state, these substrate-enhanced molecules 'loosen' up a bit, i.e. get a little ‘wild’, and then in this enhanced ‘state’ begin to interact (react) with each other to form the bonded bound state structure "ammonia molecule" (NH3); in the human case, the bonded "dihumanide molecule" forms.
Fourth: when the reaction is done, and the substrate has been modified a bit, kind of like a pre-cursor to human 'waste', the newly formed nitrogen molecule detaches, as a happily formed unit, and floats off leaving a kind of possible modified 'residue' or structural change on the substrate surface.
Systems come in two varieties: ‘closed’ or ‘open’. Open means that both energy and matter may cross the boundary. Closed means that energy but not matter may cross the boundary. Human systems, by definition, may either be defined as open or closed depending upon where the boundary is drawn. If we define the integumentary layer (skin) to be the boundary and the internal organs (body) to be the system, then human systems are definitively ‘open’ to the flux of both matter and energy. If we define the boundary to the the edge of the human molecular orbital (90% probability movement region) then we can approximate the system (internal to the orbital edge) to be closed to the flux of matter but not to energy (in the forms of heat and work). Below we have representative ‘system’ examples for both a mechanical and a human engine:
Substrate: the catalytic surface of the earth over which, given daily photon input, human molecules react. Regarding human molecular substrate catalytic activity, we can view nutrient ‘consumption’ and ‘excretion’ as evolved ‘substrate interactions’ tracing back to before 3.8 billion years ago when the earth began to cool and form a crust (substrate). In this manner, we can approximate the exchange of material between human molecules and the surface of the earth as a sort of ‘catalyst’ being put into the reactor vessel (habitat). At the early stages of such evolution, molecules would interact with the substrate by exchanging charged electrons and/or photons; this evolved over time to now include the exchange of larger ‘food’ particles (electrons, photons, and/or molecules)' by analogy, compare the Haber process as shown below :
Sloughing Hypothesis: a theory in human thermodynamics which postulates that mass extinctions, which occur approximately once every twenty-six million years, varying in a cyclical manner, are the result of earth molecule integumentary system self-regulatory shedding processes wherein the earth jettisons its climax ecosystem skin through a cycle of growth and renewal by a yet unknown biogeochemical process. This is analogous to how a human molecule grows and discards its epidermal and dermal layers of mammalian skin at each lunar cycle – or how a snake sheds its scale skin at each semi-yearly molt -- or how the sun sheds its magnetic skin at each sun spot cycle. This earth exoderm shedding and molecular reincorporation process results functionally to drive the biosphere back to organizational ground zero enabling it to start the molecular evolutionary buildup process again so to grow a new 'living' exosphere. We define this twenty-six-million year growth and renewal process to be earth's exodermal-regeneration cycle.
Human molecular integument (skin) accounts for 15% of its mass
Earth molecular integument (lithosphere, hydrosphere, atmosphere, biosphere) accounts for 4% of its mass
Human molecular integument (skin) renews once every 1-3 months
(600 times per lifecycle - 75 years)
Earth molecular integument (lithosphere, hydrosphere, atmosphere, biosphere) renews once every 26-30 million years (192 times per lifecycle – 15 billion years)
Solar molecular integument (magnetic skin) renews once every 11-22 years
Spontaneous: proceeding from natural feeling or native tendency without external constraint; these movements, activities, or bonding mechanisms are defined thermodynamically by large (negative) values of Gibbs free energy change ∆G.
Sun Molecule: the definition of the sun when viewed as one 'big' thermal-chemical molecule [an aggregate of at least two atoms]; definitively, the bonded interrelation of protons, neutrons, electrons, and field particles that comprise its structural integrity, being chemically-defined according to the following (approximate) ten element molecular formula and commonly-known rotating spherical structure (globe) in a plasma state:
The sun is actually a 70-element molecule (approximately) according to recent spectral measurements; however, such mass composition tables are difficult to come by; hence, here, to within a good approximate, we model the sun as a 10-element molecule. Moreover, the sun could reasonable be modeled as a 2-element molecule knowing that the sun is 99% hydrogen and helium in composition.