1. The answer is "<span>the energy required to start the reaction".
</span>This energy is called as activation energy of the reaction. If the activation
energy is high, reaction is slow. Enzymes help to carry out the reaction by
a new path by reducing the activation energy. But the energy of reactants
and the products remain as same as without enzyme.
2. The answer is "reaction in cells would be too slow to sustain life<span>".
</span>If the activation energy is very high for the reaction, then that reaction will
be very slow and will require more time<span> to complete the reaction. Then survival is
very low. Hence, the roll of enzymes is very important to sustain life.</span>
<span>Suffocation is a most leading reason of death in grain storage
bins. Grain handling industry is a high hazard industry where workers can be
exposed to numerous serious and life threatening hazards. These hazards
include: fires and explosions from grain dust accumulation, suffocation from
engulfment and entrapment in grain bins, falls from heights and crushing
injuries and amputations from grain handling equipment. </span>
I think the answer is evolution.
Earths food chain starts with the sun then it goes to producers such as plants that absorbs the sun’s energy to produce their own “food”
Ecosystems need producers because they are the start of the food chain.
Producers are consumed by first consumers, the second consumers and so on.