The DNA are like blueprints because they have the genetic information to create things within the cell similar to how blueprints have the information for a building to be constructed
Both smooth endoplasmic reticulum and a handy man's job is rarely aver the same. They will produce or fix a number of things depending on what or where the cell or person needs
The chloroplasts turns the raw material of sunlight and makes it into the energy or "food" that the plant needs to survive. This is what a local restaurant does but it turns natural ingredients into food for people to eat.