Without sodium potassium pumps, cells

Answers. Sodium/potassium pumps (Na/K ATPase) pump 3 Na out of the cell and 2 K into the cell. Without that, there would be relatively more ions in the cell. Therefore, the cell would swell up from osmosis. However, there is a basal efflux of K, (resting membrane potential), that would eventually equilibrate with the extracellular concentration.

The cells won't be able to move molecules in and out of the cells

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.