Complex sentence: Feedback inhibition is a system of self-regulation in which the result of a system or process will influence the process itself to reduce and suppress its activity while allosteric regulation is a regulation of an enzyme by an effector molecule at the protein's allosteric site.
Split into simpler sentences: Feedback inhibition is a system of self-regulation in which the result of a system or process will influence the process itself to reduce and suppress its activity. In contrast allosteric regulation is the regulation of an enzyme by an effector molecule at the protein's allosteric site.