PhysioEx Exercise 8 Activity 3

2/3/23, 8:31 PM PhysioEx Exercise 8 Activity 3 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex8/act3/ 1/3 PhysioEx Lab Report Exercise 8: Chemical and Physical Processes of Digestion Activity 3: Assessing Pepsin Digestion of Protein Name: Miranda Daniel Date: 3 February 2023 Session ID: session-a38d2981-51bd-4d6d-4059-907f738684d5 Pre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly. Experiment Results Predict Question Stop & Think Questions Where in the body does protein digestion begin? You correctly answered: the stomach. 1 The substrate for pepsin is You correctly answered: protein and peptides. 2 In this activity the substrate you will be using to detect protein digestion is You correctly answered: BAPNA. 3 Negative results with the negative controls You correctly answered: are expected and validate the experiment. 4 A spectrophometer measures You correctly answered: optical density. 5 Predict Question: At which pH do you think pepsin will have the highest activity? Your answer: pH 2.0. 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). 1 An optical density greater than zero indicates that 2

2/3/23, 8:31 PM PhysioEx Exercise 8 Activity 3 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex8/act3/ 2/3 Experiment Data Tube No. Reagent 1 Reagent 2 Reagent 3 Boiled Time (min) Temp (°C) Optical Density 1 Pepsin BAPNA pH 2.0 Buffer + 60 37 0.00 2 Pepsin BAPNA pH 2.0 Buffer - 60 37 0.40 3 Pepsin Deionized Water pH 2.0 Buffer - 60 37 0.00 4 Deionized Water BAPNA pH 2.0 Buffer - 60 37 0.00 5 Pepsin BAPNA pH 7.0 Buffer - 60 37 0.03 6 Pepsin BAPNA pH 9.0 Buffer - 60 37 0.00 Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. Review Sheet Results You correctly answered: BAPNA digestion has occurred and pepsin is active. Pepsin would be most active You correctly answered: in the stomach. 1 Which two tubes validated the results of the experiment? You correctly answered: tubes 3 (pepsin, deionized water, pH 2.0 buffer) and 4 (deionized water, BAPNA, pH 2.0 buffer). 2 With more enzyme activity the optical density You correctly answered: increased. 3 If pepsin were digesting an actual protein substrate, the product would be You correctly answered: peptides and amino acids. 4 Describe the effect that boiling had on pepsin and how you could tell that it had that effect. Your answer: 1