In order to visualize all this [i.e. seeing proteins mechanically] [by seeing things as they are] in the macroscopic range, we may supplement the considerations in the Section on " The world of the renounced dimensions" (previous document) by the following account.
In muscle motion [muscle contraction and relaxation], for example, the myosin "system" shortens during contraction by about 30 percent of its length. How does one imagine that in the reversible shortening of isolated myosin molecules the total volume of the space containing the myosin molecules, and thus, anatomically speaking, the total volume of the muscle (at least of the muscle fibrilles), shortens or lengthens itself along the stretch-contraction direction? That is only possible when the molecular system of the acto-myosin is extending, without interruptions, along the whole distance of contraction, or when the "isolated" myosin molecules are mechanically strongly connected with each other (scheme : wire- bridge- or stave formation). In molecular dimensions, where there isn't something like "wire" or whatever something comparable to it, this means that the myosin molecules must have a chemical bonding connection with the "bridge", itself -- in whatever way one imagines such a bridge -- possessing normal chemical bonding chains from one myosin molecule to the next, that is, uninterrupted chemical bonding. The "bridges", which, by reason of guaranteeing appropriate connection to the myosin molecules, must also have a peptidic structure, can reasonably be reduced so far (or letting them shrivel together) that only one single chemical bond is left, having then obtained the most probable case that, at least covering the distance of the single muscle cell, the "myosin molecules" -- as they can be obtained from muscle mounts as small, still suited for experimental vitro-contraction, aggregated fibrous elements -- are closely and directly interconnected into a single myosine giant-molecule. And that also beyond the boundaries of the cell, in the fashion of plasmodesms (= protoplasmatic offshoots connecting cells with cells), there are sufficient bonding bridges to obtain an effective bonding continuum along the whole muscle distance.
A variant of the muscular element is present in heart-muscle tissue, whose impressive survival function in an appropriate and controlled medium soon had attracted attention. The following case is interesting (after I. Fischer) :
Two fresh pieces of tissue from the heart of a chicken embryo growing in the same culture, each pulsating with a particular rhythm, show, after concrescence of both cultures a synchronous rhythm. If, however, one piece of tissue is taken from an embryo of a duck [and the other still from that of a chicken], then, after concrescence (is it [here] really a true bond-like growing-together [because here we have to do with two different species] ? ), we do not see synchronous twitches, and each tissue sample maintains its own rhythm.
Chicken- and duck-heart epithelium doubtless have different plasm structure and therefore -- in precisely the same conditions (of the outer culture) -- cannot at all twitch in the same normal-rhythm. The initial difference of the twitches in the two chicken heart pieces are partly phase shifts, partly dependent on coincidental and medium conditions as, for instance, the magnitude of piece of tissue, which, in any case, do not obstruct adaptation [synchronization]. In all probability they truly grow together in bonding fashion, and then assuming the same rhythm is evident.
This finding does rightly speak in favor of a complete bonding structure and a rhythm dependent upon it, and not [in favor] of it to show a resulting performance of a small-molecular active ingredient (compare hormonal influence on pulse frequency) which as tact-triggering and as tact-maintaining may certainly be present, but not as tact-determining (as example of the beloved pendulum pictures with unspecific energetic drive and pendulum-specific frequency).