25588
While fast rebinding occurs from a " downward " ( heme pointing ) substate of the methionine , the slow rebinding involves interconversion between an " upward " substate , from which rebinding cannot occur , and the downward substate .
 Chemical: heme; Chemical: methionine
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: heme; Chemical: methionine