proton pumps
"Proton pumps are like other types of ion transporters (Section 4.7) that are able to translocate ions as the result of conformational changes within the protein"
"Proton pumps are like transport proteins- moving against gradient."
"The process could also be seen as analogous to cycling uphill or charging a battery for later use, as it produces potential energy. The proton pump does not create energy, but forms a gradient that stores energy for later use."
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.