If the chemical enzyme pepsin was mixed with some proteins in a test tube in a laboratory, which of these outcomes would you predict? a)pepsin would probably not break down proteins in the test tube because enzymes cannot exist outside of the human body. b)pepsin would partially break down the protein molecules but would not work well due to the absence of dna in the test tube. c)pepsin would probably not break down proteins in the test tube because pepsin is designed to work at very acidic ph ranges. d)pepsin would break down the protein molecules equally well in the laboratory as in the human stomach since it is a stable chemical.