Question

1. Does PSTI inhibit trypsin itself, or does it inhibit the conversion of trypsinogen to trypsin?

Complete the table below, which summarizes the steps one might take to test the two possible hypotheses

Hypothesis	PSTI inhibits trypsin itself.	PSTI inhibits enteropeptidase.
test & assay	_____ + PSTI; _____ assay	_____ + enteropeptidase + _____; _____ assay
control treatment and results of control assay	control: _____ results of assay: _____	control: _____ + _____ results of assay: _____
predicted results if hypothesis is supported (positive test)
predicted results if hypothesis is not supported (negative test)

Answer 1

Hello! This is what you asked for, a few notes:

Biuret's test requires NaOH, CuSO4, and potassium tartrate and UV-spectroscopy at 540 nm.

Hypothesis	PSTI inhibits trypsin itself	PSTI inhibits enteropeptidase
Test & Assay	PSTI + trypsin + proteinic substrate (i.e. peptone or ovalbumin) followed by Biuret’s test	PSTI + enteropeptidase + proteinic substrate, then followed by Biuret’s test
Control treatment	trypsin + proteinic substrate followed by Biuret’s test	PSTI + proteinic substrate followed by Biuret’s test
Results of control assay	Positive for Biuret’s test (i.e oligopeptides produced)	Negative for Biuret’s test
Predicted results if hypothesis is supported (positive test)	Negative for Biuret’s test (i.e no oligopeptides produced)	Positive for Biuret’s test
Predicted results if hypothesis is not supported (negative test)	Positive for Biuret’s test	Negative for Biuret’s test