PhysioEx Lab Report Exercise 8: Chemical and Physical Processes of Digestion Activity 3: Assessing Pepsin Digestion of Protein

2/20/26, 3:40 PM PhysioEx Exercise 8 Activity 3



PhysioEx Lab Report
Exercise 8: Chemical and Physical Processes of Digestion
Activity 3: Assessing Pepsin Digestion of Protein
Name: Morris
Date: 20 February 2026
Session ID: session-548796e3-c3da-0c11-1d4d-977215df4735

Pre-lab Quiz Results
You scored 100% by answering 5 out of 5 questions correctly.

1 Where in the body does protein digestion begin?

You correctly answered: the stomach.

2 The substrate for pepsin is

You correctly answered: protein and peptides.

3 In this activity the substrate you will be using to detect protein digestion is
You correctly answered: BAPNA.

4 Negative results with the negative controls

You correctly answered: are expected and validate the experiment.

5 A spectrophometer measures

You correctly answered: optical density.


Experiment Results
Predict Question
1 Predict Question: At which pH do you think pepsin will have the highest activity?

Your answer: pH 2.0.

Stop & Think Questions
1 Which of the following tubes are negative control tubes?

You correctly answered: tubes 3 (pepsin, deionized water, pH 2.0 buffer) and 4 (deionized
water, BAPNA, pH 2.0 buffer).

2 An optical density greater than zero indicates that

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