• Pineapples and Proteins

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    Have you ever wondered how digestive enzymes work? How about the effects of food processing on some foods? In this project, the focus is the enzymes of pineapple. These enzymes are known as Bromelain, which is known to break down proteins. When you eat pineapples for dessert, you are helping your body’s digestive system deteriorate the complex proteins in your meal into simpler amino acids.

    These amino acids are vital in the production of protein-based molecules such as muscle tissue and neurotransmitters.
    Once bromelain is absorbed through the small intestines, it can reduce inflammation and irritation that causes imbalance and discomfort to your body. With the help of this project, you can see how bromelain works. Each step will test help assess the effects of Bromelain on protein.

    What you need:
    • A can of pineapple
    • A fresh pineapple
    • A liter or liquid Jell-O or a box of unflavored gelatin
    • A package of frozen pineapple
    • Goggles
    • Teaspoon
    • Test tube rack
    • 4 Test tubes

    How to do it:
    1. Get a mixing bowl and prepare the gelatin or the liquid Jell-O using the directions indicated on the package.
    2. Using a teaspoon, add 3 ml of liquid gelatin into each test tube.
    3. Use your 1st test tube as your control. Do not put anything in it but the gelatin.
    4. Place a piece of fresh pineapple into the 2nd test tube.
    5. Place a piece of canned pineapple into the 3rd test tube.
    6. Place a piece of frozen pineapple into the 4th test tube.
    7. Rest the test tubes on the test tube rack.
    8. Immerse the test tubes in an ice bath.
    9. Remove all the test tubes when the 1st test tube’s gelatin has already set.

    Are there any differences among the 4 test tube setups? What have you observed? How did the pieces of pineapple affect the gelatin in each test tube? What can you say about the pieces of pineapples and how they affected the gelatin?
    You can modify this project by selecting another fruit that has a proteolytic enzyme like bromelain. Research it well. Device other methods by which you can observe how it acts on proteins.

  • Strength of a Bag

    If you take a plastic bag and fill it with items until It breaks, will another layer of plastic bag make the first plastic bag stronger? Is it safe to say that if a plastic bag is made thicker by layering more plastic nags in it, they could contain more items?
    This project tests the linear relationship between the number of bags layered up and the weight they can support. There could be a change or none at all.
    What you need:
    • Several plastic bags
    • A weighing scale
    • Uniform weights

    Use plastic bags because they are easy to acquire in bulk. The weights will simulate the items that you place in the plastic bags when you shop around or transport things. A place to hang the plastic bag is helpful. An existing iron nail on a wall or a metal hook on your gate will do fine.

    How to do it:
    1. Take one of the bags and find its breaking point. Hang it somewhere and fill it with sandbags or Ziploc bags filled with sand. Be sure to place a weighing scale under the plastic bag. Keep filling the bag until it breaks. Note what part of the bag starts to tear. As the bag breaks, the weights will fall on the weighing scale. When this happens, the exact weight limit of the single plastic bag should show.
    2. Insert one intact plastic bag into another. One plastic bag lines the other, making an extra thick plastic bag. Hang it over the weighing scale again and fill it with sandbags. Record the weight at which it breaks. Repeat the process using more plastic bags, at least three times.
    3. The more repetitions you perform, the more data you collect.
    Analysis of Data:
    With the data, you gather, create a graph. Use the variables “Weight Held” and “Number of Plastic Bags”. What is your conclusion? What is the overall behavior of the bag strength as you added more plastic bags?
    Also, try this experiment with paper towels or paper bags and see which brand is the toughest.

  • Water Pressure and Depth

    Water Pressure and Depth

    Have you ever watched scuba divers on tv? They face many challenges when they dive. The deeper that a scuba diver descends, the more dangerous the dive becomes. During a dive, divers can experience lots of different problems. Some of these problems can be lightheadedness, joint pain, coordination loss, and even paralysis. Why?
    The answer to that question has to do with air, gas, and even pressure.
    Did you know that water pressure is much more dense than air pressure?
    In this experiment, you’re going to observe how pressure changes with depth.

    What You’ll Need:

    Sharpie (marker)
    Duct tape
    1 clear 2-liter bottle with lid
    3 in. nail with a sharp point
    An adult to help


    1. With the scissors; remove the label from the bottle so that you can observe what happens within the bottle.
    2. Using the ruler and marker; make a mark on the bottle that’s 3 inches from the bottom of the bottle.
    3. Make another mark that is 8 inches from the bottom of the bottle. Do this directly above the first mark that you made.
    4. With the cap still on the bottle, lay the bottle down on a flat surface. Your bottle should now be horizontal.
    5. Have an adult use the sharp nail to poke a hole into the two marks that you made on the bottle.
    6. Using your duct tape, put a small piece of tape over the holes that were made to cover them.
    7. Fill the bottle, clear to the top, with water.
    8. You can either set the bottle at the side of the sink with the holes facing toward the sink or you can take it outside for this next part.
    9. Quickly remove the tape from both holes and watch what happens!
    10. What is your observation?

    When the tape is removed, water will shoot out of both of the holes. The bottom hole has the water exiting the bottle more forcefully. Why?
    The bottom hole is deeper under the water and therefore under greater pressure. There is more weight pressing down on the bottom so it makes the water exit with more force.

    A Step Further:

    For a full experiment and project, make other holes at different depths in the bottle. Test to see if the water pressure increases at a steady rate the closer the holes are to the bottom. Try using a wider container. Discover whether or not more water matters or if depth is what matters most.
    You can also use salt water vs. regular water. Salt water weighs more than regular water.

  • Aquatic Respiration Project

    Aquatic Respiration Project

    Have you ever sat down and watched fish in a tank or in a pond? Did you ever watch how the fish breathes? We, often call the flaps on either side of the head, gills, but those aren’t really the gills at all; they’re operculum. The gills are actually underneath those flaps and are responsible for pulling the oxygen out of the water so that the fish can breathe! When a fish opens its mouth, it pulls the water into its body and expresses that water through the gills and out of the “vents” called the operculum. The gills take the oxygen out of the water and spread it through the fish’s body so that it can survive underwater. Just like us, the fish breathes out carbon dioxide so when the fish exhales, that’s what goes back into the water. Fascinating!

    What you’ll be doing for this experiment is determining whether or not a fish’s respiration changes in response to changes in its environment.

    How Do Fish Breathe Underwater?

    Items that you will need:

    2 (two) identical fish containers or bowls
    2 (two) goldfish. One large goldfish and one smaller goldfish. (Please make sure, before you buy any fish that you are prepared to keep them or find them a good home.)
    Ice cubes
    1 (one) large plastic bowl (clear)
    2 (two) 1/2 cup measuring cups
    Water conditioner
    Warm water
    Graph paper

    Directions for Project:

    1. Fill the goldfish bowls with lukewarm water. (or desired temperature for your species of fish)
    2. Place one fish each into the two identical bowls.
    3. Start with the smaller fish. Set your stopwatch for 1 minute. Count the number of times you see the small fish breath within that minute. It’s important to be as consistent as possible so choose one of the two ways to watch how many times the fish breathes in one minute. You can either count how many times the fish opens its mouth or count each flap of the operculum. Do this three times and calculate the average. Write down the number of breaths.
    4. Repeat step 3 for the larger fish.
    5. For the next step, add the proper amount of water conditioner in half of a cup of water and pour the mixture into the bowl of the small fish. Set your stopwatch for one minute and count how many breaths the fish takes. Write down the number of breaths as well as any behavioral change.
    6. Repeat process with the larger fish.
    7. Fill up the large clear container with cold water. Place the fishbowl inside the cold water. (set the fishbowl itself into the container of water. Don’t mix the water from the large container and the fishbowl. Do not empty the fishbowl into the large container.)
    8. Using a thermometer, take the temperature of the water that’s inside the large container and write it down.
    9. Add ice cubes to the large container.
    10. Again, count the fish’s breathing, per minute, until the temperature on the thermometer stops changing.
    11. Repeat the process with the larger fish. (remember to replace the water inside the large container with more cold water.)
    12. On a line graph, chart your findings. Use the horizontal line should be the number of times that the fish breathes per minute and the vertical line should indicate the temperature of the water.
    Is there a connection between the fish’s breathing rate and the temperature of the water?

    Fish breathe more when they are in warm water. Their breathing slows down when the water is colder. Fish also breathe faster when they are scared or excited. A smaller fish breathes more times per minute than a larger fish.

  • Make your own Rheostat

    A rheostat is a small device that allows you to control voltage flow by using a knob or a dial.

    Items you will need:

    1. One (1) dry cell lantern battery or Two (2) “D” cell batteries.

    2. A 2-inch long piece of wire

    3. A socket and a bulb from a flashlight.

    4. Roughly 16 inches of wire.

    5. One pair of wire cutters.

    6. A very long spring. This may be acquired from anywhere. A roll-up window shade has a spring inside the wooden portion. Ask a parent or adult to help.


    1. When connecting the two batteries, connect them so that the negative pole of one battery is connected to the positive pole of the opposite battery.

    2. Using the 16-inch wire, cut it in half with your wire cutters. Attach one piece to each open end of the joined batteries.

    3. Using the light socket, connect one end of the wire to the terminal of the light socket and one end of the wire to one end of the spring.

    4. Using the 2-inch wire, connect it to the other terminal of the light’s socket.

    5. Taking the end of each wire, connect them. Pay attention to how brightly the bulb begins to glow.

    6. Taking the short wire, slowly move it down the length of the spring.

    What happens?

    Because the steel wire of the spring is not a great conductor of electricity, you will find that the further away you move the wire, the dimmer the light becomes. The more wire that the electricity is forced to move through the more resistance. Thus, you have less electricity. Congratulations, you have just created a rheostat! This device is used to calculate and vary the amount of current.

  • How Plants Cool Down Houses

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    During hot weather, there is nothing better than to have a cool house to serve as your oasis. Aside from your air conditioning, plants can also contribute to making your home cooler.

    How do they do this?

    You’re about to find out!

    What you need:
    • A reflector lamp or the sun (the lamp should have a 100-watt incandescent bulb)
    • 2 shoe boxes or cardboard boxes
    • Different types of plants in their pots (ask your parents or grandparents if you can use their plants)
    • 2 functional thermometers (digital would be best)
    • 1 small can of dark colored paint
    • 1 small can of white paint

    What you do:
    There are a few steps you need to do in this experiment:

    Step I:
    1. Get your boxes and place them at an equal distance from the lamp for equal lighting.
    2. Place the thermometers inside your boxes.
    3. Position your plants between the lamp and one of the boxes, so that they cast a shadow over the boxes.
    4. Turn your lamp on.
    5. Measure the temperature of the air after a while. Which of the two boxes has a raised temperature? Find out if the temperatures change.

    Do you think the number of plants make a difference?

    Step 2:
    1. Paint one box black and one box white.
    2. Place them at an equal distance from the lamp for equal lighting.
    3. Place the thermometers inside your boxes.
    4. Position your plants between the lamp and one of your boxes, so that they cast a shadow over the box.
    5. Turn your lamp on.
    6. Measure the temperature of the air after a while. Which of the two boxes has a more elevated temperature? Find out if the temperatures differ. Do you think the number of plants that give shade to the boxes make a difference?

    Step 3:
    1. Place the plants between the lamp and one of the boxes, so that the plants cast a shadow that covers most of the box.
    2. Turn on your lamp.
    3. Be sure to measure the air temperature in each box over time. Which of the boxes has a more elevated temperature? Does the temperature fluctuate? Remove or add plants. You can even change the box they cover. Which box maintains the lowest temperature?

    What you discover
    During the summer, plants shield the interior of our homes from sunlight, making our homes a lot cooler. Trees give shade to a home with its branches and leaves. This decreases the sunlight that strikes the house, lowering its temperature. During winter, trees and smaller plants shed their leaves to allow more sunlight to enter the home, raising the temperature inside it.

    The color of your walls and roofing also affect your home’s temperature. Light colors make sunlight bounce off. These are ideal paint colors during the summer. Dark colors absorb sunlight. These colors are for winter.


    Have you ever wondered how those colored carnations got their hues? You can make different colored flowers that are unique from all others. All you need to do is purchase the flower you want.
    What you need:
    • White colored flowers (rose or carnation)
    • Water
    • Pair of scissors
    • Food coloring
    • Small cups
    How you do it:
    1. Pick the colors you want for your flowers.
    2. Get your cups and pour water in them.
    3. Drop your chosen colors into each cup or water. Just a few drops will not do. Make sure that the water becomes dark. This will give you the desired effect.

    4. Get your pair of scissors and cut a centimeter off the bottom of the stem.
    5. Immerse the stem into one of the cups, which you filled with colored water.

    6. Wait about twenty-four hours. [Sometimes the colors appear after just a few hours. Others take at least one to two days.
    *** If you want to create multicolored flowers, ask an adult to split the stem with a sharp razor. Dip the two or three divisions into different colors. This will produce a multicolored flower.

    The process behind this coloring effect in flowers is called transpiration. Transpiration is a process through which a plant absorbs water through its stem. When the water reaches the flowers and leaves, it evaporates through certain openings calls stomata. During evaporation, a pressure forms. This pressure pulls in more water into the plant. It is like a tree sips through a straw. On a hot day, some trees can transpire gallons of water. Light, wind, temperature, and humidity are the factors that affect the rate at which a plant transpires.

    A plant transpires faster when there is a bright light. This happens because the stomata open much wider, allowing more carbon dioxide into every leaf. Carbon dioxide is one of the ingredients in photosynthesis.

    In higher temperatures, transpiration is quicker. This is brought about by faster diffusion and evaporation.

    When the environment is windy, the diffusion of water vapor from the leaves is also quicker. This results in faster transpiration.
    In humid conditions, transpiration is slower. Once the leaves are surrounded by moist air, the diffusion of water vapor from the leaves slows down.




  • The Density Drink Science Project

    To understand the tricky concept of density, you should drink it. Generally, density is fascinating. It becomes cool when you make it into a tasty, healthy beverage, which you can share with the entire class as you explain.
    What you need:
    • Various juices with different levels of density. [In juices, the density is measured by the amount of fruit or sugar inside it. More sugar in the fruit means that the fruit is denser. Avoid getting canned or powdered fruits. They will not work well in this experiment because they will be mostly made up of water. Do a little trial to find out which natural fruit juices are denser and more colorful than the others.]
    • A turkey baster or eye dropper
    • A tall, narrow glass [A taller glass makes it easier to separate the levels of density.]
    How you do it:
    1. Before starting the experiment, you should choose which juices are denser. From your selection, you should form a hypothesis on how your drink’s density will become. Check the juices and see their water and sugar contents.
    2. Find out the least dense of all your fruit juices. Do this, so that you can display the various levels of density of all the juices you selected.
    a. Get your narrow glass and fill it to about 2.5 centimeters or an inch high.
    b. With your dropper or turkey baster, drop another juice onto the inner side of the glass, so that it runs down slowly toward the first juice you poured.
    c. See if your second juice settles below or above the first juice.
    d. Move on to the next juice, and the next.
    3. Keep in mind that the juices that settle at the bottom of the glass is the densest juice. The one that rests on top of the others is the least dense of all.
    4. The moment you have determined the densities of your juices, start pouring your juices into another narrow glass with the use of your baster or dropper.
    5. Enjoy your density drink.
    Take note that the density in liquids shows you the amount of mass or atoms in each volume. If you have 200 ml of plain water in one cup and 200 ml of sugar water in another cup, the sugar water will be heavier. The sugar molecules make the sugar water denser because they disperse throughout the water molecules.
    [Link: ]

  • Is Dog Saliva Antiseptic?

    Is animal saliva antiseptic?

    Stories about pioneers, travelers, or hunters who made it through their injuries because certain wild animals happened to lick their open wounds. Many cultures believe this. There is even a French saying, “Langue de chien, langue de médecin,” which translates to “A dog’s tongue is doctor’s tongue.”

    We’ve all heard that a dogs lick can be antiseptic but is it really or is it–like so many things–an old wives tale.

    Problem stated:

    Are there components in animal drool that can kill bacteria in wounds?
    What you need:
    • Fresh saliva from either your cat your dog (some dogs drool a lot; cats drool sometimes as well when they like the way you pet or massage them)
    • 5 petri dishes that have sterile agar medium
    • Non-pathogenic, freeze-dried Staphylococcus bacteria found on the epidermis
    • Sharpies for labeling the petri dishes
    *** There should be adults present to handle the bacterial cultures

    How you do it:
    a. Inoculate one petri dish with few grains of the Staphylococcus bacteria. Do not use too much. Label it as “Control 1”. Set the petri dish aside.
    b. Inoculate the second petri dish with ¼ teaspoon of your pet’s saliva. Label the petri dish as “Control 2”.
    c. Inoculate the third petri dish with the Staphylococcus bacteria and a little of your pet’s saliva. Label the petri dish as “Sample A”.
    d. With your bare hands, rub your hair, your pet, and then the grass in your garden. Just make your hands as saturated with germs as possible.
    e. Take another petri dish and press your hand lightly on the agar for a second or two. Label the petri dish as “Sample B”.
    f. Repeat step “d” and add a bit of your pet’s saliva on the areas where you pressed your hand. Label the petri dish as “Sample C”.
    g. Isolate the petri dishes and put them somewhere in the room where they cannot be disturbed.
    h. Check the petri dishes after 12 hours, 24 hours, 36 hours, and 48 hours.
    i. Compare the size of the bacterial colonies in every dish. See if the petri dishes that contain your pet’s saliva reduced the bacterial colonies.
    j. Learn about lysozyme, opiorphin, IgA (immunoglobulin A) and peroxidases, which are present in the saliva of animals. These components are known to heal wounds because of their antiseptic properties.

  • Does Peeling Fruit Make it Deteriorate Faster?

    When you have too many seasonal fruits in your kitchen, you often want to taste them all at the same time. There are times when you pick a bunch of them and peel them all at the same time for convenient eating. Yet, have you ever thought that peeling the fruit removes its first layer of protection?

    Like other organic substances, fruits need protection, even if they are still up in their trees. Once they are a picked, they start to deteriorate because they lose their living connection of nutrients. Their skin delays their deterioration.

    Before you start this experiment, consider the many factors that contribute to the deterioration of fruits:
    • Microorganisms
    • Excess moisture
    • Exposure to oxygen
    • Extreme temperatures

    When a fruit starts to rot, it breaks down into simpler substances. This is the process of decomposition. It is nature’s way of recycling, which is imperative to keep matter in biome. In the natural world, the faster something decomposes, the better. This is because all the raw materials are returned to the soil much quicker. Once in the soil, other organisms can start using them immediately.

    The Question stated:
    Does peeling a fruit make it rot more quickly?
    What you need:
    • Two each of the following
    o Oranges
    o Apples
    o Strawberries
    o Peaches
    • Pen and paper for your notes
    • Knife
    • Small plastic bags

    How you do it:
    *** Note that this experiment yields the best results during winter. There are usually no bugs during this time of year.
    1. Take one of each fruit and cut it in two. Place them in small plastic bags.
    2. Take each of the whole fruit and place them in separate plastic bags.
    3. Observe the process of decomposition that happens daily.
    4. Note which of the fruits starts to rot first.
    5. Make a record of your observations with the use of a chart.