Name _____________________________________________________________

Microorganisms B2 Workbook

Complete this set of assignments and, to move on to the next set of assignments, you must:

Select and complete two (2) assignments.

Assignment CompletedLab – Can Microbes Tell the Difference? Lab – Do the Mystery Samples Contain Life?

Lab – How Safe Are We?

Lab - The Yeast of Our Worries. Lab – Now You See It, Now You Don’t.

Select and complete one (1) assignment.

Assignment CompletedComplete Yellow Jackie Mystery (online activity).

Complete Two Forks, Idaho Mystery (online activity).

Note: All labs must be completed in groups of 2, 3, or 4.

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Can Microbes Tell The Difference? (lesson from Microbeworld.com)

Goal To compare the energy content of various sweeteners by measuring yeast’s production of carbon dioxide when using sweeteners as food. Materials Microscope Microscope slide and cover slips 4 to 7 plastic bags 10 teaspoons rapid rise yeast Sharpie® Teaspoon Ruler 8-ounce measuring cup Warm water 1 L clear, regular soda 1 L clear, diet soda 2 teaspoons sugar 2 packets Sweet’N Low® 2 packets Equal® Variety of other sweet products (grape juice, lemon juice, non-fruit drinks which

contain fructose, etc.) 4 3-ounce paper cups Masking tape 1 1-L container (optional)

Safety Notes Wash hands before and after the activity. Food and gum are not allowed. Discard used plastic bags in the trash at the conclusion

of the activity.

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Procedure 1. Closely examine some of the yeast. Record your observations. Put a small number of grains of yeast and a few teaspoons of water in a, plastic bag. 2. Place a drop of the water mixture on a slide with a cover slip and examine it under magnification. 3. Before you begin your experiment, determine whether your bags will leak when filled with water. Fill each bag part way with water, seal the bag, and turn it in every direction to make sure there are no tears in the bag. If water leaks from any part of the bag, get a new bag. 4. Set up your experiment using four bags. One bag is the control and the other three are the experiment bags. Each bag should have the same amount of liquid and one teaspoon of yeast. Bag #1 would be the control and contain warm water, yeast, and no sweetener. Why? Bags #2, #3, and #4 would each have a different sweetener such as sugar, Sweet’N Low®, Equal®, diet soda, regular soda, or fruit juice. (If you are testing one of the powdered sweeteners, use warm water with your sweetener and yeast mixture. If you are testing a sweetened liquid, just include the liquid and yeast without water.)

5. After adding a different sweetener to each of the bags, carefully seal the bags trapping as little air as possible. Mix the contents well. Keep the contents of the bags at a constant temperature by placing them on an overhead, or holding them in your hands or under your arms. You will monitor the bags every 10 minutes, so make note of the time.

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6. While you wait, taste a sample from the unused portions of each of the sweeteners you tested. 7. After 10 minutes, determine the amount of gas created in each of the bags. Record your observations. One way to measure the amount of gas produced is to measure the diameter of each bag with a ruler. Squeeze each bag to collect the gas in the bottom portion of the bag. Roll the flattened part of the bag around the bottom. Measure the diameter of each rolled bag. How do the results compare to your predictions? Graph your results. Repeat the process after 20, 30, and 40 minutes.

1. Record your observation of the yeast granules below. __________________________________________________________________ __________________________________________________________________ 2. After you placed water in the bag, what happened to the grains? Is the water mixture clear or cloudy? __________________________________________________________________ __________________________________________________________________ 3. Describe what you saw when you observed the yeast cells under the microscope. __________________________________________________________________ __________________________________________________________________

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4. Of your mixtures, which is sweetest? __________________________________________________________________ 5. Which do you think will provide the most energy for the yeast? Write down your predictions. __________________________________________________________________ __________________________________________________________________

Bag Mixture Data

Bag Diameter Bag # 10 min 20 min 30 min 40 min

1

2

3

4

Use this data to make a bar graph 5. Compare the labels of the sweeteners you used. How many calories were in each? a. b. c.

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6. Do you see a relationship between the number of calories and the results you got? Explain your answer. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

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10 20 30 40

Bag

1 D

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er in

Cen

timet

ers

10 9 8 7 6 5 4 3 2 1 0

Minutes

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10 20 30 40

Bag

2 D

iamet

er in

Cen

timet

ers

10 9 8 7 6 5 4 3 2 1 0

Minutes

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10 20 30 40

Bag

3 D

iamet

er in

Cen

timet

ers

10 9 8 7 6 5 4 3 2 1 0

Minutes

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10 20 30 40

Bag

4 D

iamet

er in

Cen

timet

ers

10 9 8 7 6 5 4 3 2 1 0

Minutes

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Do the Mystery Samples Contain Life? (Optional)

(a lesson plan from the NASA Astrobiology: Science Learning Activities for Afterschool guide) Materials

Three clear containers Sugar Container 1 Container 2 Container 3 Hand lenses Three small sheets of paper Spoon

Procedure 1. Observe the mystery samples in the three jars to find out if they contain anything living. You may use all of your senses except taste. Be sure to look closely with the hand lenses. Touch, listen, and smell. Record your observations below. Jar 1 __________________________________________________________________ __________________________________________________________________ Jar 2 __________________________________________________________________ __________________________________________________________________ Jar 3 __________________________________________________________________ __________________________________________________________________

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2. Get the sugar. Add one teaspoon of sugar to each sample. Do you see any changes to any sample yet (remember, you just added food!)? __________________________________________________________________ 3. Add warm water to the mystery samples. Look for changes. (Pour enough water into each jar to just cover the mystery samples). Record any changes you see. __________________________________________________________________ __________________________________________________________________ 4. Add another teaspoon of sugar to each jar. Does adding more food (sugar) re-start the fizzing in Jar 3? What is happening in Jar 2? __________________________________________________________________ __________________________________________________________________ 5. Try adding more water to Jar 3. Does that re-start the reaction you saw before? Has your opinion about which jar contains the living thing changed at all? Why or why not? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 6. Which samples are living?

Jar 1 – Yes/No (circle one) Jar 2 – Yes/No (circle one) Jar 3 – Yes/No (circle one)

Explain your choices for each question. __________________________________________________________________ __________________________________________________________________

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__________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 7. Find out what each jar contained. Were you choices in #6 correct? Why or why not? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 8. Explain how you can determine if something is alive. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

How Safe Are We? (Optional) (activity from PBS for Teachers)

Purpose To model how health investigators evaluate a building’s potential for harboring microbes. Overview Students map their school for hotspots of microbial growth. They swab different locations around the school and culture the samples in Petri dishes. From the microbial abundance and diversity in their cultures, students gain insight into how the environmental conditions at each location influence the presence of microbes.

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Materials Two cotton swabs Two agar plates Incubator

Safety Concerns: Bacteria. Students will not open agar plates. When using agar plates, students will wear gloves and goggles. Procedure 1. Answer the following questions. a. What are “germs”? _____________________________________________________________ __________________________________________________________________ b. What types of organisms are they and what do they look like? _____________________________________________________________ __________________________________________________________________ c. Do disease- and non-disease-causing microbes exist in the same general places? Explain. _____________________________________________________________ __________________________________________________________________ d. List environmental conditions that might affect how well microbes grow in a particular place. _____________________________________________________________

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__________________________________________________________________ __________________________________________________________________ __________________________________________________________________ e. How might one determine whether microbes are present and what kinds they are? _____________________________________________________________ __________________________________________________________________ 2. Your challenge is to test the school and find where microbes like to live, to tell whether the number of microbes growing in your test area is high or low, you need to make a comparison. Name some places that you predict will have: (a) Many microbes _____________________________________________________________ __________________________________________________________________ (b) Few microbes _____________________________________________________________ __________________________________________________________________

Explain why you think these places have different numbers of microbes. ______________________________ ______________________________

__________________________________________________________________

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3. Think about the ways your school is cleaned. Choose a cleaning method, such as mopping a floor, sponging a table, vacuuming a rug, or disinfecting a sink. Predict how much change there will be in the number of microbes before and after someone cleans using this method. Location being cleaned: ________________________________________________ Method used to clean this location: _______________________________________ (a) Predicted abundance of microbes before cleaning: High Medium Low (b) Predicted abundance of microbes after cleaning: High Medium Low (c) Explain how you think the cleaning process affects the numbers of microbes. _____________________________________________________________ __________________________________________________________________ 4. Your teacher will give you and a partner two agar plates. This will let you take two samples. You could sample two different locations. Alternatively, you could do a before-and–after test to see how well a cleaning method works. Describe the test you and your partner plan to do. __________________________________________________________________ __________________________________________________________________ 5. Sketch how much growth you think will be on the Petri dishes after several days.

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6. After your teacher approves your testing idea, get two Petri dishes. Label the bottom of each one with your initials, the date, and where and when you will obtain the sample.

7. Use the following sampling technique to collect microbes for your investigation.

DO NOT touch the cotton swab. Gently brush the end of the swab over an inch or two of the surface to be

sampled. Tilt the lid of the Petri dish at 45 degrees and so it still is over the dish. Keep

the lower edge of the lid in contact with the base of the plate.

Gently brush the end of the swab in a zigzag pattern fully across the agar, brushing eight to ten times across the surface. Cover all parts of the dish.

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Close the lid and seal the dish with tape, firmly securing the top to the

bottom. (FIGURE C)

Store all dishes in a warm, dry place, as designated by your teacher. 8. After several days, examine the Petri dishes. Sketch what the growth in each dish looks like.

9. Determine the amount of growth in each dish. Get a Percent Cover Estimation sheet from you teacher and decide which picture most closely matches the appearance of your dishes. Estimated percent coverage for the:

Situation 1 dish _______ % Situation 2 dish _______ %

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10. Different types of microbes can have different colors, shapes, and textures when growing in colonies on a Petri dish. How many different types of microbes can you identify? Use, use a hand lens and estimate the number of different kinds of microbes growing on the:

Situation 1 dish _______ Situation 2 dish _______ 11. How well did your results match your predictions? Explain. __________________________________________________________________ __________________________________________________________________ 12. What do your results reveal about the presence of microbes in the two situations you tested? __________________________________________________________________ __________________________________________________________________ 13. What kinds of environmental conditions do microbes seem to prefer? __________________________________________________________________ __________________________________________________________________

The Yeast of Our Worries (Optional) (from Microbeworld.org)

Have you ever been to a hospital? Did you notice the smell? Hospitals go to great lengths to create a germ-free environment. Can you think of some things that may prevent microbe growth? Purpose To investigate strategies for reducing microbial growth. Materials

Three clear cups One measuring teaspoon Rapid-rise yeast

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Sugar One eyedropper Warm water (40oC) Masking tape One stirring rod Household products such as mouthwash, soap, detergent, hydrogen peroxide, cola,

toothpaste Safety Concerns: Household items; warm water. Use gloves and goggles while doing this experiment. Use gloves while handling water. Procedure 1. Select two of the household products to use as test solutions. Set your three cups out on the table in front of you. Use masking tape to label one as control, and the other with the names of the test solutions you will use. Fill each glass 1/3 full of warm water (400C). Add two teaspoons of sugar to each and stir to dissolve. Add one teaspoon of yeast to each glass and gently stir. 2. Add five drops of test solution to each of the numbered cups. For the control glass, add five drops of water. Place them in a warm area of the room. The warmer it is, the faster the yeast will grow. See the diagram on the back.

3. Examine the cups every 10 minutes for 30 minutes. Measure and record the height of the layer of foam. At 30 minutes, line up the cups in order of foam height.

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Data Table

Cup Minutes Foam Height Control

Test Solution #1 Test Solution #2

Questions and Analysis 1. Which substances were most effective in limiting the growth of yeast? __________________________________________________________________ __________________________________________________________________ 2. Which substances did not limit the growth of yeast? __________________________________________________________________ __________________________________________________________________ 3. How do you explain the differences in the amount of foam produced? __________________________________________________________________ __________________________________________________________________ 4. Construct a bar graph of your results. 5. What did you learn from this activity? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

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__________________________________________________________________ __________________________________________________________________ __________________________________________________________________

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Now You See It, Now You Don’t (lesson from MicrobeWorld.com)

Maybe you’ve heard the term "biodegradable." It basically means something capable of being broken apart into simpler substances by natural biological processes. But what are these biological processes that break some things down? Why do some things biodegrade more readily than others? In this experiment, you’ll investigate the biodegrading process of commercial packing peanuts. Follow the directions to do complete this experiment. Materials Six clear plastic or glass jars (minimum 1-cup volume) Marker Masking tape Teaspoon Measuring cup Pipette Test tube Large spoon Seven biodegradable packing peanuts made of starch Seven polystyrene, or Styrofoam, peanuts Iodine tincture solution (drugstore antiseptic version that contains iodine and

iodide salts; should be brown) 1½ cups aged tap water (let tap water sit out overnight to "age" and lose its

chlorine) Compost activator that contains live microorganisms (available at garden supply

stores; be sure the label says it contains live microorganisms and not just extra nutrients)

Corn starch Slice of raw potato

Safety Concerns: Use of chemicals and microorganisms. Wear gloves and goggles when doing this activity.

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Procedure 1. Lay a potato slice out on your table. Put drops of iodine at 4 separate locations on the slice. Record you observations on the worksheet. 2. Put a drop of iodine on polystyrene and a biodegradable packing peanut. Answer the questions on the worksheet. 3. Label your jars 1 through 6. Put ¼ cup or 50 mL of water in each. Put 1 teaspoon of corn starch in jars 1 and 2. Put two biodegradable peanuts in jars 3 and 4, and two polystyrene peanuts in jars 5 and 6. Add one teaspoon of compost activator to jars 2, 4, and 6. Mix the contents in each jar. See Figure 1.

4. Test the contents from each of your jars for starch. Put five drops of the solution from the first jar in a test tube. Add a drop of iodine to the solution. Record your results. Rinse your test tube thoroughly before testing the contents from the next jar. 5. Each day retest the contents from your jars for starch. Record your results.

Data and Analysis 1. Record your observations when you place the iodine drops on the potato. __________________________________________________________________ __________________________________________________________________

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2. What happened when you placed the iodine on the peanuts? __________________________________________________________________ __________________________________________________________________ 3. Is the result similar to the reaction you got when you put the iodine on the potato? What does this tell you about the makeup of the packing peanuts? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Complete the table each day when you add the iodine.

Reaction to Iodine Drops In Jar (Circle One) Day Jar 1 Jar 2 Jar 3 Jar 4 Jar 5 Jar 6

1 Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No

2 Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No

3 Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No

4 Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No

5 Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No

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4. Which day did you see first see changes in each jar?

Day First Change Seen in Jar Day Jar 1 Jar 2 Jar 3 Jar 4 Jar 5 Jar 6

1

2

3

4

5

5. What do you think would happen if you buried a starch peanut and a polystyrene peanut in the soil during the fall, and then dug them up in the spring? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 6. Do you think that the amount of bacteria or starch affect the rate of starch breakdown? Explain you answer. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

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Yellow Jackie Mystery (an activity from Access Excellence)

What It’s About? You are helping a man named Terry to sail a yacht from South America to New Zealand. You are called in to investigate an outbreak of disease on board a second yacht. Three crew members on the second yacht have recently fallen ill. You interview the crew members, consult a medical reference, and observe other clues to determine what diseases the ill crew members have. Is It True Science? The narrative itself is fictional, but the scenario is based on actual events and contemporary science research and discoveries. Solving the Mystery

You should have a pencil and paper at your side, to take notes as you go through the story.

You should organize and label your notes as you go, under broad categories such as "Kerry's Symptoms," "Disease Symptoms," "Disease Progression," "Events" and so on.

Evaluate your information. Is this a fact or an opinion? Notes

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Solution

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Two Forks, Idaho Mystery (an activity from Access Excellence)

What It’s About? You are a medical investigator on vacation in Idaho. You are called in to investigate an outbreak of salmonellosis, an infectious disease. In this case, the disease is caused by the Salmonella paratyphi A bacterium, typically spread from human to human by contaminated water or food. You interview the people known to have had contact with the victims, and determine who the disease carrier must be through deductive reasoning. Is It True Science? The narrative itself is fictional, but the scenario is based on actual events and contemporary science research and discoveries. Solving the Mystery

You should have a pen and paper at your side, to take notes as you go through the story.

You should organize and label your notes as you go, under broad categories such as "Victim." "Disease," "Victim's Food," "Events" and so on.

Evaluate your information. Is this a fact or an opinion? Notes

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Solution