In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

[EX Q]: Question: The outer surface of the heart changes from positive to negative during what? Answer: depolarization
[EX A]: The outer surface of the heart changes from positive to negative during depolarization.

[EX Q]: Question: What phase is pure chlorine present as? Answer: gas
[EX A]: Gas phase is pure chlorine present as.

[EX Q]: Question: Where are integral proteins embedded? Answer: libid bilayer
[EX A]:
Integral proteins are embedded in libid bilayer.