The centre of the nucleus is an atom
<span>Enzymes work by reducing the energy of activation increasing the potential energy difference between reactant and product decreasing the potential energy difference between reactant and product adding energy to a reaction reducing EA adding a phosphate group to a reactant</span>
aka B
Well for the very last sentence it would be if any of the organs shut down it could seriously hurt someone or possibly even kill them if their brain,heart or some other important organ shuts down it could kill them.
There are other minor organs where if it shuts down it wouldn't really hurt the person too much. Sorry I couldn't help you with the other ones though.
Extinction of losing its species hope this helps you
