Living things obtain and use energy so alive?
100% (all living organisms of them have a rage of tolerance)
Just to add on over time they have develiped a tuff outer layer to stop weather and insects from harming them.
Answer:
A substance that speeds up a chemical reaction—without being a reactant—is called a catalyst. The catalysts for biochemical reactions that happen in living organisms are called enzymes. Enzymes are usually proteins, though some ribonucleic acid (RNA) molecules act as enzymes too.
Explanation: