What part of the turkey is the tenderloin?
Turkey tenderloin is generally sold separately from turkey breast and weighs between six to 12 ounces. The tenderloin, much like turkey meat in general, must be cooked up to 160 degrees Fahrenheit. The turkey tenderloin is a versatile ingredient and can be cooked by either roasting, sautéing or grilling. Other preparation methods include coating it in crumbs or marinating it in various savory and sweet ingredients. Source: busycooks.about.com