In ecology, commensalism is a class of relationship between two organisms where one organism benefits without affecting the other. It compares with mutualism, in which both organisms benefit, amensalism, where one is harmed while the other is unaffected, and parasitism, where one benefits while the other is harmed.n ecology, commensalism is a class of relationship between two organisms where one organism benefits without affecting the other. It compares with mutualism, in which both organisms benefit, amensalism, where one is harmed while the other is unaffected, and parasitism, where one benefits while the other is harmed.
Drug interactions also may occur when two drugs that have similar (additive) effects or opposite (canceling) effects on the body are administered together. For example, there may be major sedation when two drugs that have sedation as side effects are given, for example, narcotics and antihistamines.
Cells regulate enzyme activity through two methods: allosteric inhibition and competitive inhibition. Allosteric inhibition is when something (an ion, an organic chemical, etc â¦.) bonds to a site on the enzyme (not on the active site), and changes the shape of the enzyme. Competitive inhibition is when something (an ion, an organic chemical, etc.) enters the active site so that the true substrate cannot enter into the enzyme to have a reaction.