Question

gives reasons for some substances are needed and some are discarded in the cell​

Answer 1

This is your answer

Answer 2

Toxic damage to cells can result in individual cell death, and if enough cells are destroyed, tissue or organ failure can occur, eventually leading to the organism's death. It's practically impossible to distinguish between cellular and biochemical toxicity in a discussion of toxicity.

Cell death and most visible cellular changes are caused by metabolic changes within the cell or in the surrounding tissue. However, a hazardous chemical or physical agent can cause cell damage without impacting a specific chemical in the cell or its membrane in a few conditions.

Heat and radiation, for example, can harm a cell by coagulating its contents.There are no specific chemical interactions in this scenario. A lack of critical nutrients (such as glucose and oxygen) might deprive a cell of the components it needs to survive.