Results from the pepsin experiment
You can see that the first 3 tubes (on the left) have cleared (3 only partially).
They all started with the enzyme pepsin and differing amounts of acid.
The other 3 tubes (on the right) are still cloudy.
So pepsin alone, and acid alone, do not cause clearing. Nor does the control with neither.
This page relates to a BioTopics unit on ENZYMES AND DIGESTION - Action of pepsin on proteins