paramecium uses its cilia to sweep the food along with some water into the cell mouth.
Enough food particles must build at the base of the oral groove to trigger engulfing. Once there is enough food built up, the food particles are drawn into the paramecium's mouth and form a food vacuole. In other cells vacuoles are used as storage, and it is not different in the paramecium except the vacuoles used in digestion or food storage have special properties to allow the diffusion of enzymes and nutrients. The food is held within a vacuole while digestion takes place. Enzymes in the cytoplasm permeate the wall of the vacuole and digest the food inside. The nutrients that are released from the food particle are similarly diffused through to the outside of the vacuole into the cytoplasm, nourishing the paramecium.
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