Which term is used to describe the amino acids which cannot be synthesized by the cell but must be acquired from an outside source?

Essential amino acids

Explanation:

Some amino acids cannot be produced in our body instead they are extracted from the external food sources which are known as essential amino acids Food consumed ,provides essential amino acids. During digestion food is broken down into simple substance and protein within it is digested. Once the protein is digested, essential amino acids are extracted. In totality, there are 9 essential amino acids.

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.

it marks things for degradation via the proteasome. it alters there celluar location.