ABSTRACT
The loss or leakage of the cell’s life-giving proteins was a sign of pathology that if left unchecked would lead inevitably and inexorably to cell death. The two, life and protein permeability, appeared mutually exclusive. The first was that a mechanochemical system of vesicle transport accounted for protein movement between compartments within the cell and to the outside. The second was that protein molecules were unable to pass through biological membranes. If a concentration gradient of protein was indeed responsible for release, discharge from the granules would continue unabated until they were emptied despite the constant volume and this is just what happened. The permeability of the granule membrane to the proteins it stored had completely upended the vesicle theory’s raison d’etre. The labeled protein had passed through the cytoplasm en route. Exchange occurred freely between medium, cytoplasm, and granule—but importantly not the endoplasmic reticulum.
