Fleas are small, wingless insects that live on the bodies of mammals such as dogs, cat, and humans. they feed on the blood of these mammals. what type of relationship between fleas and mammals?

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