How do enzymes speed up chemical reactions

High energy produced during the metabolism of reactant to product. Due to the large free energy of activation, the speeds of uncatalyzed biochemical reactions are often exceedingly slow. Enzymes lower this energy of activation so that more molecules have adequate energy to carry into the transition state to speed up the rate of reaction.

the answer would be 3

the offspring would all be white. if the parents are both white flowers then they have the genotype rr, which when crossed results in an all white punnet square.