Why is the interaction between predator and prey called a cycle

Predators are the ones who consume the prey and rely on them as a food source, while prey rely on predators to control their population.

Explanation:

yes it is weird but true

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