When we eat food, most people never think about the enzymes that are needed to help with digestion. Think about your favorite meal, now think back to a time when you had that meal. Did you ever stop to think about how your saliva was breaking that food down? Or how your stomach was secreting enzymes and acids to turn that meal into a thick digestible liquid, known as chyme? Most people probably haven’t, since thinking about your favorite meal turning into chyme is not appetizing! However, enzymes play a vital role in digestion, without enzymes we would be unable to eat. In humans, there are two important enzymes that aid in digestion: ptyalin (salivary amylase) and pepsin. Ptyalin is found in saliva and helps break down starches into simpler sugars. Pepsin is found in the stomach and helps to break down proteins into smaller peptides.

Data: An experiment was performed that examined the activity of ptyalin and pepsin under varying levels of pH. Examine the attached chart to answer the questions

Using the data, plot the results of the experiment. Upload a picture of your data.

Examine the graph. Identify the optimal pH for ptyalin. How does the date tell you this is the optimal pH?

Examine the graph. Identify the optimal pH for pepsin. Why is this the optimal pH?

Connect the optimal pH of each enzyme to their location in the body. Does each optimal pH make sense for those
locations? Why or why not?

What happens when enzymes are not in their optimal pH (hint: link to protein structure)? How does this affect
enzyme activity?