12087
Nevertheless , only three to five rotameric equilibria are found for each amino acid residue , indicating a relatively low structural heterogeneity of collagen upon fibrillogenesis .
 Chemical: amino acid
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: amino acid