Eukaryotic cells have many different molecules which control the cell as it goes through the cell cycle. which of these would not be a valid reason for a cell's need to have these control molecules present?

ecotourism pay for conservation efforts.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products