"Tryptophan self-controls its synthesis." Justify this statement.

If a lesser amount of Tryptophan is present in a cell, Tryptophan acts as an inducer and binds to a repressor, leading to the synthesis of enzymes required for its production and thus its synthesis.

If an excess amount of Tryptophan is present in a cell, Tryptophan acts as a promoter, preventing the further synthesis of necessary enzymes for its production and thus its synthesis.

If an excess amount of Tryptophan is present in a cell, Tryptophan acts as a co-repressor, preventing the further synthesis of necessary enzymes for its production and thus its synthesis