Biochemistry. A salt or ester of citric acid. It is a key intermediate in the citric acid cycle which is the central metabolic pathway involved in the degradation of carbohydrates, fats and proteins to generate cellular energy. Citrate as a chelator can be used as anticoagulant in blood samples.
Citric acid is one of the most common acids in plants. It exists in a variety of fruits and vegetables, most notably citrus fruits.