The plasma membrane's function is primarily supported by channels and pumps.
Channels facilitate the passive transport of ions and molecules across the membrane, while pumps are involved in active transport, moving substances against their concentration gradient. The "gelatin-like material" you mentioned likely refers to the fluid mosaic model of the plasma membrane, which describes it as a flexible structure with various proteins and lipids that can move laterally within the layer.
In summary, the best answer would be channels and pumps. If that option was not given directly in your responses, then it’s important to identify that the functions of the plasma membrane significantly rely on these elements.