Lab 4: Enzymes
INSTRUCTIONS:
· To conduct your laboratory exercises, use the links to the instructions for each lab, found in the “Course Content” section of the classroom.
· On your own and without assistance, complete this Lab 3 Answer Form electronically and submit it via the Assignments Folder by the date listed on your Course Schedule (under Syllabus).
· Type your answers into the gray shaded boxes provided after the questions and in the tables. The boxes will expand as you type.
· When necessary, insert graphs prepared in Excel, or image files (scans, photos, etc.) into the clear boxes provided.
· Save your Lab 3 Answer Form in the following format: LastName – Bio 102 Lab – Lab 3 Answer Form (e.g., Largen – Bio 102 Lab – Lab 3 Answer Form).
· You should submit your document in a Word (.doc or .docx) or Rich Text Format (.rtf) for best compatibility.
· Please note that this answer form also serves as a grading rubric. The grading information for each question is provided in red text in parentheses following each question/graph/table, etc. Skipping a requested question, part of a question, table, graph, etc., will result in the designated amount of percentage points being deducted from the grade for this lab answer form.
Experiment 1: Enzymes In Food (41 points)
Data Tables and Post-Lab Assessment
Table 1: Substance vs. Starch Presence
(1 point each cell = 13 points)
| Substance Name | Resulting Color | Presence of Starch?(yes or no) | |
| Positive Control: | Ginger Root | ||
| Negative Control:Student Selects | |||
| Food Product:Student Selects | |||
| Food Product:Student Selects | |||
| Required: | Saliva |
Take a picture of your results. Include a note with your name and date on an index card in the picture. Insert picture here (3 points):
Post-Lab Questions
1. a) What were your controls for this experiment? b) What did they demonstrate? c) Why was saliva included in this experiment? (2 points each part = 6 points)
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| b | |
| c |
2. a) What is the function of amylase? b) What does amylase do to starch? (2 points each part = 4 points)
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| b |
3. a) Which of the foods that you tested contained amylase? b) Which did not? c) What experimental evidence supports your claim? (2 points each part = 6 points)
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| b | |
| c |
4. Saliva does not contain amylase until babies are two months old. How could this affect an infant’s digestive requirements? (1 points)
5. There is another digestive enzyme (other than salivary amylase) that is secreted by the salivary glands. a) Research to determine what this enzyme is called. b) What substrate does it act on? c) Where in the body does it become activated, and why? (2 points each part = 6 points)
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| b | |
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6. Digestive enzymes in the gut include proteases, which digest proteins. a) Why don’t these enzymes digest the stomach and small intestine, which are partially composed of protein? (2 points)
Experiment 2: Effect of Temperature on Enzyme Activity (59 points)
Data Tables and Post-Lab Assessment
Table 2: Balloon Circumference vs. Temperature
(1.5 point each cell = 15 points)
| Tube | Temperature (°C) | Balloon Circumference (Uninflated; cm) (same value applies to all tubes) | Final Balloon Circumference (Inflated; cm) | Difference in Balloon Circumference (cm) |
| 1 – (Cold) | ||||
| 2 – (Room Temp.) | ||||
| 3 – (Hot) |
Take a picture of your results. Include a note with your name and date on an index card in the picture. Insert picture here (3 points):
Post-Lab Questions
1. What reaction is being catalyzed in this experiment? (2 points)
2. A) What is the enzyme in this experiment? b) What is the substrate? (2 points each part = 4 points)
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| b |
3. A) What is the independent variable in this experiment? b) What is the dependent variable? (2 point each part = 4 points)
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| b |
4. How does the temperature affect enzyme function? Use evidence from your data to support your answer. (2 points)
5. A) Draw a graph of YOUR DATA for balloon diameter vs. temperature. Scan or photograph your graph and insert the image in the space below. Graph must have title (0.5 points), x-axis label and units (1 point), y-axis label and units (1 point), data points (1.5 points), line (1 point) (part a = total of 5 points) B) What is the correlation? ( part b = 2 points)
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| b |
6. Is there a negative control in this experiment? If yes, identify the control. If no, suggest how you could revise the experiment to include a negative control. (2 points)
7. A) In general, how would an increase in substrate alter enzyme activity? . (part a = 2 points)
B) Draw a graph to illustrate this general relationship. This graph can be general but should still have a title (1 point) and labels for the axes (2 points), and a line (1 point) Scan or photograph your graph and insert the image in the space below. (part b = 5 points)
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| b |
8. A) Design an experiment to determine the optimal temperature for enzyme function, complete with controls. B) Where would you find the enzymes for this experiment? C) What substrate would you use? (part a = 7 points, part b = 3 points, part c = 3 points)
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