19133
Two types of intramolecular H - bonds , namely N ... H - N and O ... H - C , are found to play important roles in influencing the planarity of the peptide planes and geometry around the alpha - carbon atoms of the dipeptides .
 Chemical: H; Chemical: N; Chemical: H - N; Chemical: O; Chemical: H - C; Chemical: alpha - carbon; Chemical: dipeptides
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: H; Chemical: N; Chemical: H - N; Chemical: O; Chemical: H - C; Chemical: alpha - carbon; Chemical: dipeptides