The word anabolism refers to constructive, buildup, or synthesis reactions while the word catabolism refers to destructive, breakdown, or digestive reactions. What does it mean to say that in a cell, catabolism fuels anabolism?

Anabolic reactions need energy.

Explanation:

Anabolic reactions (like the build up of fatty acids) are active processes and need energy. Catabolic processes like respiration will provide the ATP required to build up macromolecules. Thus, catabolism fuels anabolism.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: