The movement of protons through atp synthase occurs from the

cytoplasm and channel gates

Explanation:

The movement originates from the cytoplasm. This is the fluid medium through which ions are shuttle from one place to another. However, though simple as it might appear to be, the movement requires carrier proteins. The are proteins that facilitate in the movement of the ions. These proteins have specially controlled gates called channel proteins. These are regulated proteins that open and close based on hydrogen ion concentration. These proteins are able to facilitate the movement of ATP molecules.

lower, it's not as dense as chocolate syrup.

choco syrup is more like a solid than a liquid and even turns solid if it gets slightly cold,

orange juice however is a 95% liquid and has a very low viscosity