Stimulation of a cell by a molecule that the cell itself makes is called
stimulation

Autocrine stimulation

Explanation:

In autocrine signaling, the cell produces ligands that are also able to bind receptors on its surface. This is different from paracrine signaling whereby a ligand produced by a cell does not bind its surface receptors but does so on other cell types. These two types of signaling are important for the development of an organism.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.