instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Carried through body happens if cancer cells enter the blood stream.
answer:
What happens if cancer cells enter the blood stream?

question:
You see a faster reaction rate when the concentration of reactants is higher.
answer:
What kind of reaction do you see when the concentration of reactants is higher?

question:
A cell's membrane provides a barrier to keep extracellular materials from mixing with its internal components.
answer:
How does a cell's membrane keep extracellular materials from mixing with it's internal components?