11741
Here we employ a new method to quantify the proton motive force in living cells from the redox poise of the bc ( 1 ) complex measured using multiwavelength cell spectroscopy and show that the correct stoichiometry for complex I is 4H ( + ) / 2e ( - ) in mouse and human cells at high and physiological proton motive force .
 Chemical: 4H ( + )
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: 4H ( + )