Activity 1 - Pepper Experiment
For week four (4), you will be learning about microbes and the importance of washing your hands thoroughly! We will see why washing with soap and water is better than using water alone.
Microbes can be found all around us and are often hard to see because they are so small (sometimes you can see them under a microscope). Microbes can be found in almost all environments including the air, soil and water. The common types of microbes are called bacteria, viruses and fungi. We have millions of beneficial microbes that live in and on our body that help us function (such as lactic acid bacteria that help break down food so we can digest it) and keep us happy and healthy. However, some microbes can make us very sick. Our immune system is trained to fight off and destroy most microbes that make us ill, but sometimes the microbes can beat our immune system and cause us to be sick (e.g. cold, flu, strep throat). Medicines that kill bacteria or at least stop them from growing and multiplying are called antibiotics. But antibiotics do not work against viruses so it’s important to identify the microbe before using an antibiotic treatment.
Harmful microbes can enter the body via cuts on the skin or can enter through our nose, ears, eyes or mouth. Washing your hands regularly with soap and water can reduce the number of harmful microbes on your hands which can stop the spread of microbes and reduce the likelihood of being ill.
Essential Concepts:
Microbes: Are microscopic, living things that are found all around us. The most common types are called bacteria, viruses and fungi.
Areas of focus: Biology, Chemistry
Aim: To understand why we should use soap to wash our hands and that hand washing can prevent the spread of infection.
Materials Needed:
Microbes can be found all around us and are often hard to see because they are so small (sometimes you can see them under a microscope). Microbes can be found in almost all environments including the air, soil and water. The common types of microbes are called bacteria, viruses and fungi. We have millions of beneficial microbes that live in and on our body that help us function (such as lactic acid bacteria that help break down food so we can digest it) and keep us happy and healthy. However, some microbes can make us very sick. Our immune system is trained to fight off and destroy most microbes that make us ill, but sometimes the microbes can beat our immune system and cause us to be sick (e.g. cold, flu, strep throat). Medicines that kill bacteria or at least stop them from growing and multiplying are called antibiotics. But antibiotics do not work against viruses so it’s important to identify the microbe before using an antibiotic treatment.
Harmful microbes can enter the body via cuts on the skin or can enter through our nose, ears, eyes or mouth. Washing your hands regularly with soap and water can reduce the number of harmful microbes on your hands which can stop the spread of microbes and reduce the likelihood of being ill.
Essential Concepts:
Microbes: Are microscopic, living things that are found all around us. The most common types are called bacteria, viruses and fungi.
Areas of focus: Biology, Chemistry
Aim: To understand why we should use soap to wash our hands and that hand washing can prevent the spread of infection.
Materials Needed:
- 2 small bowls
- Water
- 1 packet of black pepper
- 1 soap
Procedure/Instructions:
Challenges:
Think about these questions while you are working:
Connection to the real world:
The results of your experiment with and without soap should have been different. When the soap was on your finger the pepper should have moved towards the edges of the bowl. Our hands have oil on the surface, which microbes stick to. When we use soap, the oil is broken down and removed and the microbes can be washed away – just like the pepper was pushed to the edge of the bowl with the soap
Washing hands in water alone eliminates visible dirt and grime, however, soap is required to break up the oil on the surface of the hands which traps microbes. Warm water (rather than cold) increases compliance of hand washing and can improve the performance of some soaps.
- Fill both bowls with water. Sprinkle pepper on the surface of one bowl. The pepper should float to the top. The surface of the water in the bowls represents your hands. The pepper represents dirt and harmful microbes that need to be washed away.
- Dip your hand into a plain bowl of water and then dip your finger into the pepper water.
- Observe what happens and write down in your notebook. You can also take a photo to record what has happened.
- Wash your hands with the soap and leave a little soap on the end of your finger and dip into the pepper water. Alternatively, squirt some hand soap into the pepper water directly from the dispenser.
- Observe what happens and write down in your notebook. You can take a photo to record what has happened.
Challenges:
Think about these questions while you are working:
- Why do you think we use soap to wash our hands?
- What happens when you dip your finger in the bowl without soap?
- What happens when you dip your finger in the bowl with soap?
- When should we wash our hands? What can happen if we don’t wash our hands regularly?
Connection to the real world:
The results of your experiment with and without soap should have been different. When the soap was on your finger the pepper should have moved towards the edges of the bowl. Our hands have oil on the surface, which microbes stick to. When we use soap, the oil is broken down and removed and the microbes can be washed away – just like the pepper was pushed to the edge of the bowl with the soap
Washing hands in water alone eliminates visible dirt and grime, however, soap is required to break up the oil on the surface of the hands which traps microbes. Warm water (rather than cold) increases compliance of hand washing and can improve the performance of some soaps.
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Activity 2 - Petri Dish Part 1
Essential Concepts:
Areas of focus: Biology, Chemistry
Aim: To investigate how to make a homemade petri dish and how to mix together a culture medium that will encourage bacteria growth.
Materials Needed:
- Microbes: Are microscopic, living things that are found all around us. The most common types are called bacteria, viruses and fungi.
- Agar: Is a substance extracted from red-purple algae which scientists use to grow microbes in petri dishes. It comes in a powder form which is added to a mixture of nutrients and water that forms a gel.
- Petri dish: a special plastic dish used to grow and study microbes.
- Sterile: Free from microbes/ completely clean.
- Sterilization: to use heat to kill microbes.
- Contaminate: to make impure or unsuitable by contact or mixture with something unclean or unwanted.
- Antimicrobial: A substance that kills or prevents the growth of microbes.
- Antibiotic: An example of an antimicrobial that kills or prevents the growth of harmful bacteria inside the body.
Areas of focus: Biology, Chemistry
Aim: To investigate how to make a homemade petri dish and how to mix together a culture medium that will encourage bacteria growth.
Materials Needed:
- 100 ml of water
- 1 packet of agar or 1 pouch of gelatine
- 1 low sodium beef bouillon cube
- 1 tsp or small packet of sugar
- *Microwave-safe cup or pot and stove
- *Stove or microwave
- Measuring Cup
- *Measuring Spoons
- 2-3 petri dishes
- Parafilm or tape
- 5 cotton swabs
- Soap from week 4
- Paper
- Lab apron
- Goggles
SAFETY NOTES: ADULT INVOLVEMENT REQUIRED.
This experiment also involves boiling water. Microbes can be dangerous and should not be touched or allowed to become airborne. Once this experiment is started, it must remain sealed and be properly disposed of .
Make sure to perform the activity as a team (parent/grandparent/adult/helper and student). Please read the instructions out loud, wear safety protection and make sure you have all the equipment before you start.
Part 1: Preparing the petri dishes:
This experiment also involves boiling water. Microbes can be dangerous and should not be touched or allowed to become airborne. Once this experiment is started, it must remain sealed and be properly disposed of .
Make sure to perform the activity as a team (parent/grandparent/adult/helper and student). Please read the instructions out loud, wear safety protection and make sure you have all the equipment before you start.
Part 1: Preparing the petri dishes:
- Wipe down your workspace/ bench with cleaner or spray to sterilize. Wash your hands with soap thoroughly (sing the ABCs).
- Student: Measure out 100 ml of water.
- Student: Mix together the water, agar powder, sugar and beef cube in a microwave safe cup or pot if you will be using a stove to heat the mixture.
- Adult: Bring the mixture to a boil on the stove. If using the microwave, stir at one minute intervals and watch carefully until the gelatin or agar is dissolved. Remove the boiling liquid from heat and cover. Let it cool for about five minutes.
- Adult: Pour the medium carefully into clean petri dishes or containers, until 1/3 to 1/2 full. Work quickly to replace the lid over the petri dish to reduce the risk of contamination from the air. Allow dishes to cool completely (~ 1 or 2 hours). The gelatin or agar should make the growth media hard like jello. When your plates have hardened, store them upside down in a cool place, like a refrigerator, before using.
Part 2: Swabbing surfaces:
Challenges:
You can try these additional exercises:
1. When your petri dishes are ready, collect some bacteria from your hand or the hand of a volunteer. (Make sure the person hasn’t washed his or her hands too recently!) Do this by rubbing the sterile swab over the palm in a zigzag pattern. Remove the cover from the petri dish and lightly rub the swab back and forth in a zigzag pattern on the agar. Turn the dish a quarter turn and zigzag again. Cover the dish and repeat steps two and three for the other dish, using a new sterile swab. Label the dishes “Test” and “Control.” (You may want to do more than one test dish, so you can compare the results.)
2. Cut the paper into small “sensitivity squares.” Use permanent ink to label the squares for the different types of hand cleaners you are going to test, e.g., “R” for regular soap, “A” for antibacterial soap, and “S” for hand sanitizer. Using tweezers, dip each square into the appropriate cleaner. Blot the excess cleaner on a paper towel and then place the squares on the agar in the “Test” dish. (Spread the squares out so there is distance between them.) Add one square of plain blotter paper to test if blotter paper by itself has any effect. Don’t put any squares in the “Control” dish – this one will show you what the bacterial growth will look like without any soap.
Connection to the real world:
As you can see from the results of your petri dish, microbes are all around us! You will hopefully see a difference between the swab that came from a dirty hand and the swab that was from a thoroughly washed hand with soap (if not, that may be a sign that you should revisit your hand washing technique)!
You should see different shapes, sizes and colors depending on what you sampled. You might have grown some helpful microbes such as bacteria that are used to turn milk into yogurt, cheese, and other dairy products. Or cyanobacteria (which used to be called blue-green algae) live in water and perform photosynthesis, which results in the production of much of the oxygen we need to breathe. Or you may have harmful pathogens like some that are found in spoiled or contaminated food, resulting in food poisoning. Or bacteria that cause plaque buildup on our teeth, which can lead to cavities and gum disease.
Before the discovery of antibiotics and soap, many bacterial diseases had no cure and usually resulted in death. Antibiotics work by killing bacteria or stopping their reproduction while leaving the body’s own cells unharmed. After a time, some bacteria develop resistance to an antibiotic, and it will no longer be effective against them. Because of this, scientists are always researching new antibiotics. (Many diseases, such as chickenpox, hepatitis, or polio, and of course COVID-19 are caused by viruses rather than bacteria. Antibiotics have no effect against these diseases.) Bacterial infections are common, but many of them can be avoided by good cooking, cleaning, and hand-washing practices
- Student: Label your plates with the names of the surfaces you want to test. You can test your hand before washing, and after washing. Make sure to include a negative control (an area that will remain untouched). Be sure to label the bottom of the plate since the lid will move.
- Rub a clean Q-tip around on the surface you want to test in a zig-zag manner. Then, remove the lid from the plate and gently rub the Q-tip across the section of the plate labeled for that surface and quickly replace the lid.
- Once you have swabbed all the surfaces you want to test, seal the petri dish with parafilm (pull and stretch parafilm around the edge of the petri dish and trim) or seal with tape, flip upside down, place in a ziplock bag and store somewhere warm preferably dark (90 F is good). Depending on the weather you could find a spot outside, or find a warm device (like a cable box) and place it near.
- Observe every day and record your observations between each plate. Something should be growing after 2-3 days. What do you notice? Draw the colors, shapes and size of each section.
Challenges:
You can try these additional exercises:
1. When your petri dishes are ready, collect some bacteria from your hand or the hand of a volunteer. (Make sure the person hasn’t washed his or her hands too recently!) Do this by rubbing the sterile swab over the palm in a zigzag pattern. Remove the cover from the petri dish and lightly rub the swab back and forth in a zigzag pattern on the agar. Turn the dish a quarter turn and zigzag again. Cover the dish and repeat steps two and three for the other dish, using a new sterile swab. Label the dishes “Test” and “Control.” (You may want to do more than one test dish, so you can compare the results.)
2. Cut the paper into small “sensitivity squares.” Use permanent ink to label the squares for the different types of hand cleaners you are going to test, e.g., “R” for regular soap, “A” for antibacterial soap, and “S” for hand sanitizer. Using tweezers, dip each square into the appropriate cleaner. Blot the excess cleaner on a paper towel and then place the squares on the agar in the “Test” dish. (Spread the squares out so there is distance between them.) Add one square of plain blotter paper to test if blotter paper by itself has any effect. Don’t put any squares in the “Control” dish – this one will show you what the bacterial growth will look like without any soap.
Connection to the real world:
As you can see from the results of your petri dish, microbes are all around us! You will hopefully see a difference between the swab that came from a dirty hand and the swab that was from a thoroughly washed hand with soap (if not, that may be a sign that you should revisit your hand washing technique)!
You should see different shapes, sizes and colors depending on what you sampled. You might have grown some helpful microbes such as bacteria that are used to turn milk into yogurt, cheese, and other dairy products. Or cyanobacteria (which used to be called blue-green algae) live in water and perform photosynthesis, which results in the production of much of the oxygen we need to breathe. Or you may have harmful pathogens like some that are found in spoiled or contaminated food, resulting in food poisoning. Or bacteria that cause plaque buildup on our teeth, which can lead to cavities and gum disease.
Before the discovery of antibiotics and soap, many bacterial diseases had no cure and usually resulted in death. Antibiotics work by killing bacteria or stopping their reproduction while leaving the body’s own cells unharmed. After a time, some bacteria develop resistance to an antibiotic, and it will no longer be effective against them. Because of this, scientists are always researching new antibiotics. (Many diseases, such as chickenpox, hepatitis, or polio, and of course COVID-19 are caused by viruses rather than bacteria. Antibiotics have no effect against these diseases.) Bacterial infections are common, but many of them can be avoided by good cooking, cleaning, and hand-washing practices
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MONDAY 3PM - QUIZ TIME WITH COLE & LAUREN
Join Lauren and Cole for an interactive quiz session using mentimeter for your chance to win prizes! Click here to play at 3pm. |
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FRIDAY @ 10AM - OUT & ABOUT WITH CRISTY ELDRIDGE AT SPORTS TIME FAMILY PUB & GRILL
We chat with the 'Queen on 17'/ owner of Sports Time Family Pub & Grill, Cristy Eldridge about food safety and the importance of washing your hands! |
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OUT & ABOUT @ KEM KREST
We go behind the scenes at Kem Krest and learn more about hand sanitizer and how it's made! |
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Post your results on our Flipgrid page for your chance to enter our weekly prize draw!
Guest password: ETHOS2021 Click here |
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