Not sure what you mean but here's what i think
1.They are substrate-specific, because it's a lock-and-key mechanism.
2. They are re-used
3. They can catalyze reactions
4. They decrease activation energy
5. They are proteins by nature.
Answer:
it is called gene pool...
The bubbles of beer
I may be wrong pls double check
Its D for example if you have a piece of clay shaped as this rock and you put pressure on one side of the clay the side that you are putting stress on will go down with your hand because it is being held with pressure
ps. i have a hard time explainning things i can map it out in my head but not so muchin words.