When salt and sugar dissolve in water it is a physical change. The chemical makeup of the salt and sugar are not changed.
Physical change
Since chloroplast use energy to make food for plant cells (Photosynthesis) I could compare it to lunch money, and how you have to keep refilling up, and up, just to use it again for food, for yourself.
Gallons. You buy gasoline by the gallon.
Answer:
insulin/glucose/liver/pancreas
