instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Sucrose is formed when a monomer of glucose and a monomer of fructose are joined in a dehydration reaction to form a glycosidic bond.
answer:
What is formed when a monomer of glucose and a monomer of fructose are joined in a dehydration reaction to form a glycosidic bond?

question:
Insulin is made up of two polypeptide chains.
answer:
Insulin is made up of how many polypeptide chains?

question:
The outer surface of the heart changes from positive to negative during depolarization.
answer:
The outer surface of the heart changes from positive to negative during what?