What happens when the cell copies its chromosomes

friend we studied in cell cycle that it completes in two steps.

1)      Inter phase  (  G1, Gs, G2 phases)

2)     division phase (  Mitiosis and meosis)

*  G s  phase;

                        during G s phase cell continous start increasing in size also in this phase cell replicates it's chromosomes. and the centrosomes are divided into centrioles for spindling.

1. what is the relationship between the shape of an enzyme and the reactions they catalyze?

2. how does an enzyme inhibitor work?

separate your answers so i dont get confused : )