In the process of life, the organic substances of the cell are gradually destroyed, especially for proteins, which are essential components of membrane structures. Therefore, during the period of active functioning, each cell must independently synthesize the substances it needs. Nevertheless, the existence of a cell incapable of independent synthesis of substances is possible. These are specialized cells, for example red blood cells. These cells in a mature state live for a limited time (in humans – about 120 days) and die off as they age.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.