Internal & external audits: first-, second-, and third-party audits. 1  A first-party audit is performed within an organization to measure its strengths and weaknesses against its own procedures or methods and/or against external standards adopted by (voluntary) or imposed on (mandatory) the organization.
Precursor (chemistry) In chemistry, a precursor is a compound that participates in a chemical reaction that produces another compound. In biochemistry, the term precursor often refers more specifically to a chemical compound preceding another in a metabolic pathway, such as a protein precursor. 1 Illicit drug precursors.
/preÂ·curÂ·sor/ (preÂ´kur-ser) something that precedes. In biological processes, a substance from which another, usually more active or mature, substance is formed. In clinical medicine, a sign or symptom that heralds another.precurÂ´sory.preÂ·curÂ·sor/ (preÂ´kur-ser) something that precedes. In biological processes, a substance from which another, usually more active or mature, substance is formed. In clinical medicine, a sign or symptom that heralds another.precurÂ´sory.