Nursing

Lab 4: Enzymes

ANSWER KEY

Pre-Lab Questions

1. How could you test to see if an enzyme was completely saturated during an experiment? (2 pts)

To test this, you’d simply see if the reaction was still taking place. If the enzyme was completely depleted, the reaction could no longer occur.

2. List three conditions that would alter the activity of an enzyme. Be specific with your explanation. (2 pts)

Temperature, salinity, and acidity are three conditions that affect enzyme activity. Specific examples include:

Adding a salt packet to an enzyme would alter its activity--salt ions are often necessary for optimal enzyme activity, so too much or too little salt will slow down the rate.

Enzyme activity increases with increasing temperature, until it becomes hot enough to denature the protein (enzymes are proteins), then the activity would cease.

Enzymes have an optimum pH where they function the best. Higher or lower pH than the optimum slows the rate of activity.

3. Take a look around your house and identify household products that work by means of an enzyme. Name the products, and indicate how you know they work with an enzyme. (2 pts)

Some examples include: contact lens cleaner (protease), dish soap (amylase), cheese

(rennin), meat (papain), and starch products (amylase).

Experiment 1: Enzymes in Food

Post-Lab Questions

(Table - 2 pts)

1. What were your controls for this experiment? What did they demonstrate? Why was saliva included in this experiment? (2 pts)

This experiment is looking for the presence of the enzyme amylase. A positive control would indicate the presence of amylase and so should be something that is KNOWN to contain amylase. A negative control would indicate no amylase, so should be a substance KNOWN to not contain amylase. As written, the positive control would be the ginger root because it is known to contain amylase. The presence of amylase is indirectly tested for by testing for the presence of starch with an...