Final answer:
Each subsequent protein in the complement cascade is a precursor, which becomes active after cleavage by the preceding protein. Enzymes catalyze reactions without being consumed and have high specificity for their substrates. Inhibitors can bind to enzymes and inactivate them by inducing conformational changes.
Step-by-step explanation:
Each subsequent protein in the complement cascade is a precursor, meaning they must be cleaved by the preceding protein to be activated. The complement system functions as a cascade, where the activation of one protein leads to the activation of the next protein in the sequence, often by cleavage, which is a process that typically involves enzymatic action. In this context, a precursor is an inactive form of a protein that requires modification to become active.
When discussing enzymes and their function, it is important to note that they are not consumed by the reactions they catalyze; instead, they facilitate biochemical reactions by lowering the activation energy. Enzymes are typically made up of amino acids and are highly specific, binding to their substrates with precision at the active site. Enzyme inhibitors, like allosteric inhibitors, can bind to an enzyme and induce a conformational change that reduces the enzyme's affinity for its substrate, effectively inactivating it.