A word association test was used to determine knowledge structures on biochemistry concepts of secondary school chemistry students, aged between 18-19 years. The basic biochemistry concepts related to the topic of Carbohydrates that take place in the International Baccalaureate Diploma Programme curriculum were determined as stimulus words: "Monosaccharides", "Glucose", "Cellular respiration", "Fructose", "Disaccharides", "Glycosidic bonds", "Polysaccharides", "Starch". Students were required to provide response words for each of the eight stimulus words within the pre-determined period of time. Analysis of data was done in order to find the stimulus words with the highest number of associations in students' knowledge structures and to calculate the relatedness coefficient between the stimulus words, in order to construct the relatedness networks that should model the students' knowledge structures. The results showed that students managed to relate most of the stimulus words with strong or medium strength links, however, "Cellular respiration" remained unconnected to other stimulus words in the students' knowledge structures. [For the full proceedings, see ED629086.]