Scientists are studying compounds in a newly discovered rain forest plant. The plant produces an unusual substance that local people say acts as an anesthetic. One scientist tested the substance with the chemical indicator copper (II) sulfate and sodium hydroxide. If the test is negative, which type of macromolecule is not present in the substance?​

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process. 

Yes yes yes very good