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Butterflies: The Birds of the Insect World

4/26/2018

Spring has sprung in North America, and all sorts of long-dormant creatures are starting to reappear! Among these are the many species of butterflies, including the infamous monarch butterfly. Butterflies have inhabited the earth for about 130 million years - around the same time flowering plants started showing up as well. It’s believed that plants evolved to have flowers in order to attract butterflies and wasps (bees hadn’t quite shown up yet)!

Because these insects are so common and have been around for millions of years, we’re not really sure where the term ‘butterfly’ comes from. Some linguists have speculated that they were named so due to old folklore tales of witches in the form of flying insects stealing milk and butter from farmers! This is unique to the english language as the name for butterflies in other languages never relates to butter.

Butterfly Anatomy

Like all insects, butterflies have three main body parts: head, thorax, and abdomen. Because butterflies don’t have bones, they must have an exoskeleton that protects their soft bodies. This exoskeleton is made of chitin, which is a type of polysaccharide (carbohydrate--like sugar, but made into a long chain). On the top of their heads are two segmented, clubbed antennae.

Butterflies have two different sets of eyes they use: simple eyes and compound eyes. The pair of simple eyes, or ocelli, are used mainly to tell the difference between light and dark. Their compound eyes are responsible for most of a butterfly’s vision. These eyes are bigger, and are able to focus on individual objects. They can also detect ultraviolet light - something a human’s eyes cannot see!

To get to the nectar they eat, butterflies use a long, tubelike mouthpart called the proboscis. When not in use, the proboscis curls up underneath the butterfly’s head so it can be more aerodynamic when flying. In the center of the “mouth” there is a food tube through which the nectar is siphoned, or sucked up. Along two sides of the food tube, there are tiny muscles that control the coiling and uncoiling of the proboscis.

While the head of a butterfly is the control center for sensing things, the thorax is what allows a butterfly to move. Attached to the underside are three pairs of segmented legs and four wings. Although it might seem like butterflies only have two wings, when you take a closer look you can see the forewing and hindwing on each side of the body. Butterfly wings get their color from the scales, or little hairs that have been flattened to give color. Without a microscope, these scales just look like powder to the naked eye!

A butterfly’s wings are used mainly for flight, but they also have other functions. Patterns on the wings can help camouflage the butterfly, warn predators that a butterfly is poisonous, surprise or distract predators with flashy displays, and help a butterfly attract and communicate with other butterflies of its species. There is also a certain type of scale that doesn’t produce color, but instead gives off pheromones to communicate with fellow butterflies or predators. These scales are called androconial scales.

As with most animals, the majority of a butterflies organs are located inside the abdomen. There are tiny holes found along the sides of the abdomen that let air travel into tracheal (throat) tubes in the butterfly’s respiratory system, allowing it to breathe.These holes are called spiracles. Unlike humans, a butterfly’s mouthparts are not involved in breathing!

After passing through the proboscis and pharynx, nectar goes through the rest of the butterfly’s digestive system in its abdomen. Also located in the abdomen are the heart and reproductive organs!

Life Cycle of a Butterfly

In a previous blog post about metamorphosis, we discussed how a butterfly goes from an egg to a caterpillar, before finally becoming a butterfly!

An adult female butterfly will often lay her eggs on the underside of a leaf to protect them from predators. There, the unfertilized eggs wait for a male butterfly to fertilize them so they can begin to form and hatch as larva. The word larva refers to the growth stage of all insects with complete metamorphosis; caterpillar refers only to a butterfly or moth in this stage.

As the caterpillar grows and becomes too large for its skin, it molts, or sheds its skin. Just before they pupate (spin themselves a chrysalis, also called a cocoon) , caterpillars spin a silk mat from which they hang upside down. The silk comes from the spinneret on the bottom of its head. As it sheds its skin for the last time, the caterpillar places a stem into the silk pad to hang. After approximately 10 to 14 days as a chrysalis, the butterfly is ready to emerge.

When it emerges from its chrysalis, its wings are small and wet, and the butterfly can’t fly yet. It has to pump fluids from its abdomen through the veins in its wings to stimulate the wings to expand to their full size. Next, the wings dry and the butterfly must exercise flight muscles before it can fly. After a couple of days, the butterfly is ready to mate and the cycle begins again!

Butterfly Diet

As a caterpillar, a butterfly’s first meal is its own eggshell. For the next three to four weeks, the caterpillar will munch on the leaves of the plant from which it hatched. Milkweed is a particular favorite of the monarch butterfly. Depending on how large the plant is, a caterpillar may adventure away from its place of hatching in search of more food. But in general, caterpillars aren’t very picky eaters, unlike human babies and toddlers!

When the butterfly is fully matured, it will use its proboscis to drink nectar from flowers. Although flowers are their preferred source of nutrition, butterflies will also eat from the soft tissue of rotting fruit. When feeling particularly thirsty, they will often drink water from mud puddles and elephant dung!

Make a Butterfly Feeder at Home

If you’ve ever visited a butterfly farm or garden, you might have seen an assortment of feeders the staff use to keep the butterflies fed and happy.

Here’s what you’ll need to make a feeder from a glass jar (such as a mason jar):

- Large glass jar
- string
- nail and hammer
- half inch metal washer
- sugar
- sponge
- water
- wire

Using a hammer and a nail, punch a hole in the center of the jar’s lid. Using a half-inch thick sponge, cut about a quarter inch from one end, then cut that piece in half lengthwise that the end is about a quarter inch on all sides. Trim this piece so the sponge is about one inch long.

Insert the little piece of sponge into the hole in the lid so there is half an inch of sponge on either side. To help squeeze the sponge in the hole, you can use the nail to carefully push a little bit of the sponge through, and then pull it from the other side. The sponge should not be able to slip around inside the hole.

Turn the glass jar upside down. Cut two pieces of string that are 48" long. Wrap each string around the base of the jar and tie a double knot. The two knots should be opposite each other on either side of the jar. You will now have four ends of string extending from the jar. Take two strings on one side of the jar and tie a double knot about half way up the inverted jar. Do the same with the remaining two. Try to get the two knots at an even height, on opposite sides of the jar.

Then, take one string from each opposing knot and tie another double knot at the top of the inverted jar. Now you have a macrame-style structure to hold the jar securely and keep it from tipping over. Tie the four strings together to the metal washer. You will use this washer to hang the feeder from a tree branch with some wire.

To make your own “nectar”, mix ten parts water and one part sugar in a pot over medium heat until all the sugar is dissolved. Allow the sugar solution to cool before pouring it into your feeder jar. Once the jar has been filled, screw the lid on to form a tight seal. You can tip the jar over right before hanging it from a branch so the butterfly solution saturates the sponge in the lid

To attract more butterflies, you could try gluing some fake flowers and glass beads to the jar/string to mimic colorful flowers in the wild!

References:

Fong, Jonathan: “How to Make a Homemade Butterfly Feeder”. eHow.com

Image Credits:

Scudder, Samuel Hubbard. “Prodryas - Prehistoric Lepidoptera”. Released into the public domain. Uploaded on 4/17/18 from commons.wikimedia.org

Bingham, C. T. “Butterfly Antenna Tips”. Released into the public domain. Uploaded on 4/19/18 from commons.wikimedia.org

Kraft, Robert. “Butterfly Face”. Released into the public domain. Uploaded on 4/19/18 from publicdomainpictures.net

Kratochvil, Petr. “Blue Morpho Butterfly”. Released into the public domain. Uploaded on 4/18/18 from publicdomainpictures.net

Klimkin, Sergey. “Caterpillar Color”. Released into the public domain. Uploaded on 4/19/18 from publicdomainpictures.net

“How to make a homemade butterfly feeder”. © Jonathan Fong. Uploaded on 4/19/18 from ehow.com

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Dyeing Eggs

4/13/2018

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Easter is on April 1 this year, and it’s time to get in the spirit of spring! There are multiple traditional activities many people participate in this time of year, including hunting for hidden eggs, finding baskets with candy and other treats, and of course, dyeing eggs!

With a plethora of different colors to choose from, it’s no wonder why so many people dye their extra eggs during this time of the year. In the springtime, eggs symbolize new life and energy - plus they make great decorations!

Anatomy of an Egg

Last year, we discussed how baby birds develop inside their eggs, so let’s review the anatomy on an egg. The first part of an egg that you see is the shell. Egg shells have very diverse appearances, depending on the type of bird that laid it. Chicken egg, are usually white (which we will use for dyeing) or brown, though some chickens lay blue or green eggs! The surface of the shell is bumpy and grainy, due to the thousands of little pores that allow air and moisture into the egg. It’s made up almost entirely out of calcium carbonate (CaCO3) crystals.There’s also an outer coating on the shell, called the cuticle, that keeps out dust and bacteria.

Between the eggshell and the egg white, there are two membranes (inner and outer) that provide more defense against bacteria that may have slipped in through the shell. These layers are made of keratin; the same protein that makes up human hair.

An air space forms when the insides of the egg cool and contract after it’s laid. The air space is usually between the outer and inner membranes at the egg’s larger end, and it accounts for the crater you often see if you’ve eaten a hard-boiled egg. This air cell grows larger if it were left to age, and that’s why you should never eat an egg that floats--it floats because it’s old enough for the air space to cause the egg to float...and that makes it too old to eat!

The egg white is also known as the albumen, which comes from albus, the Latin word for “white.” Four alternating layers of thick and thin albumen contain approximately 40 different proteins, the main components of the egg white in addition to water.

The next component of an egg is the yolk. Contrary to popular belief, the yolk is not what develops into a baby bird if fertilized; it is the stockpile of nutrients that the baby bird uses to grow and develop inside the egg. The yolk contains less water and more protein than the white, some fat, and most of the vitamins and minerals of the egg. These include iron, vitamin A, vitamin D, phosphorus, and calcium, among others, making the yolk a great source of nutrition for a growing baby bird.

How the Dye Works

The colored molecules in food dye are sodium salts of phenolic acid, a naturally-occurring color compound found in the seeds and skins of fruits and vegetables. But we can’t just drip some food dye onto an egg and call it good - there are more steps involved! To make a dye mixture you need a mixture of water, vinegar, and food dye. When the dye is mixed with water, the sodium ions are dissolved and you’re left with the negatively charged part of the molecule, which is the colorful part.

When you add vinegar (which is diluted acetic acid), you’re actually flooding the dye with protons that they can bind to. Now that the dye molecules have combined with hydrogen ions, they can form hydrogen bonds. The slight positive charge the dye molecules now have are instrumental in binding to the slightly negative atoms in protein molecules and calcium carbonate of the eggshell.

So even though boiled eggs already have a slightly acidic smell, we still need to add vinegar in order for the food dye to work! The saturation of the colors on an egg depend on how well the dye bonds to the shell. This means that the less vinegar you use, the less vibrant your color will seem! However, if you don’t like the strong scent of vinegar, you can always use another type of acid - such as citric acid squeezed from a lemon! Just make sure that the pH of your dye solution is no lower than 4, or else carbon dioxide bubbles released when the acid reacts with the calcium carbonate in the shell will make streaks on your egg!

Dye Your Own Eggs!

In order for the dye to bind with your eggs, you should boil them first to make sure they don’t crack and make everything messy! To do this, gently place your eggs in a single layer in a large saucepan. Add enough cold water to cover the eggs by one inch. Cover the pan and bring the water to boil on high heat. Remove from heat and let stand 12 minutes. Pour out the hot water and rapidly cool eggs by running them under cold water (or place them in ice water) until completely cooled.

To make the dye, mix 1/2 cup boiling water, 1 teaspoon vinegar and 10 to 20 drops of food color in a cup to achieve desired colors. Repeat for each color.

Dip the hard-boiled eggs in dye for about 5 minutes. Use a slotted spoon, wire egg holder or tongs to gently add and remove your eggs from the dye. Make sure you allow them to dry before touching them! If you don’t leave them out for too long, you can eat the dyed eggs after you’ve used them as decorations.

Image Credits:

Egg diagrams property of Discovery Express Kids LLC.

Kratochvil Petr. “Colorful Eggs”. Released into the public domain. Uploaded on 3/28/17 from publicdomainpictures.net

Kratochvil, Petr. “Colorful Easter Eggs”. Released into the public domain. Uploaded on 3/28/17 from publicdomainpictures.net

Koev, Vladimir. “Easter Time”. Released into the public domain. Uploaded on 3/28/17 from publicdomainpictures.net

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Investigating Animal Behavior

3/11/2018

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Humans have been interacting, and even living with animals for thousands of years. You may have heard the phrase, “A dog is man’s best friend,” but did you know that wolves were actually the first domesticated animals? Thousands of years ago, people noticed that these wild creatures could be tamed and serve a practical purpose, giving rise to the world’s first pets.

If you’ve grown up with animals, you probably already know how they act, and how we should act around them. For example, it’s common knowledge that dogs will sniff each other’s rear ends in greeting, and cats like to scratch things to sharpen their claws. But why do they behave like this? Are these learned or instinctive behaviors? Let’s take a closer look.

Feline Behavior

The behavior of domestic cats is very different from that of cats in the wild. The major difference between the two groups is communication. Our feline companions have many unique sounds that they use to communicate with us; the most prominent one is meowing. Cats meow at us to get our attention, ask for food, or greet us when we come home. But among themselves and in the wild, cats rarely (if at all) meow at each other to communicate! The closest they get to meowing at each other is when a mother cat chirps (or softly meows) at her kittens. Otherwise, cats will purr, hiss, or growl at one another to communicate.

While dogs understand and view humans as a completely different animal, cats think of us as giant, hairless kittens. Because they learn so much of their behavior from their mothers during the first few weeks of life, they often emulate that pattern of communication with their owners! If a cat is allowed outdoors, it may bring back some sort of “gift” to their human, such as a dead mouse or bird. Cats do this because it’s how their mothers taught them to hunt and catch their own food! The mother will go out hunting and bring back her dead prey, then show her kittens how to properly eat it. She will continue to do this until the kittens are able to catch their own food.

Another learned behavior in cats is grooming. If you have ever had a cat as a pet, you may have noticed they like to stick to a schedule when it’s time to eat. In the wild, cats spend time stalking their prey before capturing and eating it. Afterwards, they will lick themselves all over to clean up any leftover food that might be on their bodies from the hunt. This behavior is something that we can still observe in domestic cats. However, most of the time it isn’t directly translated from the hunt/kill/eat/groom pattern. When kittens are first born, they need a little bit of help with relieving themselves. Once they’re full after nursing, their mother will clean them up and then lick their backsides to stimulate the nerves and get them to urinate or defecate. After the kittens can do this on their own, they can learn to use a litter box by watching their mother!

One example of instinctive behavior in domestic cats is the use of scratching posts, or just scratching in general. Most cats are attracted to anything with a coarse or textured surface; something they can really sink their claws into. Sometimes, this comes at the expense of our nice furniture. But why do they do this? There are many reasons as to why cats scratch things: removing the dead outer layer of their claws, marking their territory (they have scent glands on their paws), and stretching their bodies while flexing their paws! This behavior is completely normal and instinctive, so we don’t want to stop them from scratching. The best course of action to get cats to stop ruining furniture is to introduce objects they can scratch on, and discourage the use of things they can’t. Scratching behavior depends mostly on texture, so try covering off-limits spots with things your cat will find unappealing on their paws, like double-sided tape, foil, or even lint roller sheets.

Canine Behavior

If you’ve ever lived with a dog, you might have noticed that they tend to howl along to similar sounds, like the siren of a fire truck or a tornado warning signal. This is an example of instinctive behavior in canines. In the wild, wolves howl to let other wolves know that this is their territory and to stay away. They also howl to locate their pack members when they're apart, which helps them maintain relationships within the pack. When dogs hear something that sounds like a howl, their instinct kicks in and tells them to howl back!

Unlike cats, who don’t meow to communicate with other cats, dogs in the wild bark to communicate with each other from a distance. Compared to humans, dogs are very visual creatures - body language is the most important form of communication. However, if a fellow canine is far enough away, a dog will bark at it to get its attention, like saying, “Hello! I’m over here!”

For dogs, most learned behavior comes from interacting with, or watching other dogs interact with humans. From a young age, dogs that are kept as pets learn to follow commands and generally have “good” behavior (something that wild dogs and wolves do not have). Dogs learn by association, which means that if a behavior has a positive outcome, they’ll be more inclined to repeat that behavior. If they’re ignored or receive a negative outcome, they are less likely to repeat the behavior in the future.

When dogs are bored or hungry, they’ll go scavenging for food in places they know where it will be. Dogs are incredibly smart animals, and they understand that extra food goes in the garbage, so that’s one of the first places they look. If their owner catches them being naughty and scolds them for it, the dog probably won’t go poking around in the garbage again any time soon. But if it gets away with some food and doesn’t get hurt in the process, the dog will more than likely go back the next time it’s bored or looking for a snack!

Observe Animal Behavior

Now that we know a little bit about why animals exhibit certain behaviors, we can observe how animals interact with their environment. All you’ll need is an animal to observe and something to take notes with!

If you have pets, it’s pretty easy to study their behavior if you know what to look for. Try watching how they eat, sleep, and interact with you. What are they trying to communicate?

Depending on the time of the year, it might be a little more difficult to find wild animals to observe. In the winter there are lots of birds and jackrabbits hanging around, and maybe the occasional squirrel. Many animals are most active in the spring and fall. If you live in a city with a large population, you might have noticed that pigeons and squirrels tend to be more bold and less afraid of humans. Why is that? If you have questions about a specific behavior you observed, looking it up online is a great way to find an explanation!

Image Credits:

Langova, Anna. “Cat and Dog”. Released into the public domain. Uploaded on 3/2/18 from publicdomainpictures.net

Boardman, Emma. “Black Cat”. Released into the public domain. Uploaded on 2/27/18 from publicdomainpictures.net

Verbeek, Richard. “Big Cat”. Released into the public domain. Uploaded on 3/3/18 from pexels.com

Frerichs, Lilla. “Coyote Howl”. Released into the public domain. Uploaded on 3/3/18 from publicdomainpictures.net

Hodan, George. “Puppy Dog”. Released into the public domain. Uploaded on 3/3/18 from publicdomainpictures.net

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Iodine Clock Reaction

2/16/2018

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In chemistry, kinetics is the term we use when measuring and studying the rates of reactions. Chemical (or reaction) kinetics involves investigations of how different experimental conditions impact the rate of a chemical reaction. We also use kinetics to make reaction equations that can describe the characteristics of a chemical reaction, such as the physical states of the product(s)!

One classic experiment that showcases two chemical reactions taking place is the iodine clock reaction, discovered by Hans Heinrich Landolt in 1886. He took two colorless solutions and mixed them together. After a little time had passed, the solution suddenly turned dark blue! When he repeated the experiment, he found that the solution turned blue after the same amount of time had passed. Clock reactions (or oscillating reactions) are labeled as such because there is a sudden property change after a predictable amount of time.

In this case, the change in property happens to be a colorless solution abruptly becoming a much darker color.

Recreate the Experiment at Home!

Before we get into the reaction equations, it might be easier to see what’s going on instead of trying to imagine it. Luckily, we can recreate this famous experiment with a few items you might have in your medicine cabinet! All of the chemicals you’ll be using are completely safe, but iodine is very good at staining your skin and clothes, so you may want to wear some latex gloves just to be safe. All of the materials can be found in a drugstore or supermarket!

What You’ll Need:

Distilled (or tap) water
A few disposable cups
One 1000 mg vitamin C tablet
Tincture of Iodine (2%)
Hydrogen peroxide (3%)
Liquid laundry starch

First, prepare three solutions: a vitamin C stock, an iodine solution, and a hydrogen peroxide solution. For the vitamin C stock, crush the tablet and dissolve it in 2 oz (59 mL) of water.

The next solution will be one of the reactants. Mix 1 tsp (5 mL) of the vitamin C stock with 1 tsp of iodine and 2 oz of water. Label this as “Solution A”.

To prepare the second reactant, add 2 oz of water to 1 tbsp (15 mL) of hydrogen peroxide and 1/2 tsp (2.5 mL) of liquid starch solution. This will be “Solution B”.

Now you’re ready to begin the reaction! Carefully pour Solution A into Solution B. Then pour the entire solution into the now empty cup. Continue transferring the solution back and forth until you see the color change!

What is Happening?

Because the laundry starch contains sulfuric acid, we created the first reacting solution: hydrogen peroxide with sulfuric acid. Then we added it to a solution containing potassium iodide, sodium thiosulfate, and starch. When these are combined, it creates both the elemental and ion forms of iodine.

First Reaction:

In this reaction, iodide ions react with hydrogen peroxide to produce elemental iodine, which is blue in the presence of starch. However, before that can happen, the vitamin C quickly reacts and consumes the elemental iodine (that's what is happening in the second reaction below). That’s why we don’t immediately see the change of color!

Second Reaction:

The second reaction is much quicker than the first, so the reactions can proceed for a short amount of time before the thiosulfate (S4O62-) ion is exhausted in the experiment and the iodine-starch complex’s blue color is visible.
You can repeat this experiment as many times as you’d like! You could even try timing the reaction to see if the blue color appears at the exact same time in each trial.

References:

“Iodine Clock Reaction”. Imagination Station, www.imaginationstationtoledo.org.

Image Credits:

“Iodine Clock”. Released into the public domain under the Creative Commons Attribution-Share Alike 3.0 Unported license. Uploaded on 2/12/18 from commons.wikimedia.org

Hodan, George. “Laboratory Glassware”. Released into the public domain. Uploaded on 2/13/18 from publicdomainpictures.net

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How Snow Forms

2/6/2018

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It’s winter up here in the northern hemisphere, and with the chilly weather often comes snow! Snow is precipitation in the form of ice crystals, or frozen water. We know that water freezes at 32℉ (0℃), but contrary to popular belief, the temperature doesn’t need to be below freezing in order for snow to form. In fact, the heaviest snowfalls often occur when the air is between 35 and 32℉! If it’s warmer than about 35.6℉, the snow will melt and fall as sleet instead of ice crystals.

In last year’s blog about crystallization, we learned that snow can also be classified as a mineral because ice is an inorganic homogeneous solid. If something is inorganic, that means its chemical composition doesn’t include the element carbon. We also learned that in order for snowflakes to form, moisture in a cloud needs to freeze around a tiny particle of dust. From there, more water molecules must freeze and stick to that ice crystal to make the six arms of a snowflake.

Wet and Dry Snow

The best kind of snow to make snowballs or snow men out of is what we call “wet” snow, because it sticks together and holds its shape for a long time. But what is the difference between “wet” snow and “dry” snow?

The size and shape of a snowflake depends on how many ice crystals stick together, which is determined by the temperature of the air. Snowflakes that fall through dry, cool air will be small and powdery. They won’t stick together very much. This is what we call dry snow. It’s great for snow sports like skiing and snowboarding, but is more likely to drift in windy weather. This is dangerous while driving because it obscures the road lines from vision and often causes quite a few car accidents!

When the temperature is slightly warmer than 32℉, the snowflakes will melt around the edges and stick together to become big, heavy flakes. This creates wet snow that sticks together easily and is good for making snow sculptures, but is much more difficult to shovel due to its weight!

Make a Snow Storm in a Jar

With a few household materials, we can create suspended mixture that looks like a snow storm has been captured in a jar! As an added bonus, most of these items you can find at a dollar store so you don’t have to break the bank to have a little fun.

Here’s what you’ll need:

A mason jar or similar container
Canola oil
1 tsp white paint
1 cup water
Iridescent glitter
Alka Seltzer
Blue food coloring (optional)

The first step is to fill the jar about three quarters of the way with canola oil and set it aside. In a small or medium sized bowl, combine the white paint and water. Stir the mixture until the paint is dissolved, leaving you with white water. Sprinkle in as much glitter as you’d like and add some blue food coloring to provide a color contrast. Pour the paint mixture into the jar of oil, leaving a little bit of room at the top.

Wait for the glitter and paint mix to settle at the bottom of the jar.

To make the “snow storm” break up a tablet of alka-seltzer and drop the pieces into the jar. Watch carefully to see what happens! Once your “storm” has settled, you can add more pieces of alka-seltzer to start the process over again and again.

Image Credits:

Bentley, Wilson. “Snowflakes”. Released into the public domain. Uploaded on 1/28/18 from commons.wikimedia.org

Griffin, Peter. “Building Snowman”. Released into the public domain. Uploaded on 1/29/18 from publicdomainpictures.net

Snow in a Jar images property of Discovery Express Kids LLC.

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Edible Holiday Slime

1/27/2018

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Last year, we learned how to make Christmas slime and it was so much fun! Who wouldn’t want to play with slime? And for many people, playing with something gets much more interesting when you know you can eat it afterwards. This week, we’ll be focusing on edible slime and how it is different from the varieties of slime that aren’t safe to ingest.

Previously, we’ve used some ingredients in slime that wouldn’t be safe - or enjoyable - to eat. Slimes made with non-toxic won’t cause any harm if you happen to eat a little, but it won’t taste very good! On the other hand, slimes made with laundry detergent and borax are definitely not safe to ingest and are toxic, especially for young children. Typical slime made with glue and starch is seen below!

Most edible slimes will use condensed milk and cornstarch, which are ingredients that you can use for baking, so they are completely safe to eat and might just taste a little better too! The edible slime is still a polymer, so nothing too drastic has changed for you to be able to eat it. Polymers are a macromolecule (larger and more complex than a molecule) that has multiple parts, or monomers. When we talk about slime as a polymer, we mean that the different ingredients are bound together to become one ball of goo! For more about polymers, check out our previous blog about Christmas slime here.

Here, instead of polymer cross-linking reactions linking the molecules of glue and starch together, we get our slimy texture from the expansion of cornstarch granules in some hot liquid. As the starch granules expand, they absorb and trap the liquid, creating a gel-like consistency. In order to evenly mix all of the ingredients, we need to heat up the cornstarch so it thickens the mixture considerably. Adding heat to the cornstarch excites the molecules, making them more likely to bind with molecules of the condensed milk. Then, the starch expands and swells as it absorbs the liquid, giving you the perfect slimy texture!

Make Edible Slime!

Now that we know more about the science behind slime, let’s get to making our own! We know that most edible slimes use condensed milk and cornstarch as the main ingredients, and from there you can add any sort of flavoring you’d like, but in spirit of the holiday season here are two festive recipes to try out!

Chocolate Slime

You will need:
14 oz. can of sweetened and condensed milk
3 tbsp chocolate syrup
¼ cup cornstarch
Chocolate chips (optional mix-in)

Combine the milk, cornstarch, and chocolate syrup in a pot and bring to a boil, stirring frequently until the mixture has thickened considerably. Dust a cutting board with more cornstarch and pour out the slime in the pot onto it. You’ll want to give it a few minutes to cool down, and then you can start to knead the slime into the cornstarch. If the slime is still too thin after a few minutes of kneading, you can add a little more cornstarch. However, this slime will stay very sticky. If you’d like, you can add in a handful of chocolate chips to add to the texture of your slime!

Marshmallow Slime

You will need:
6 jumbo marshmallows
1 tbsp coconut oil (or any vegetable oil)
1 tbsp cornstarch

In a microwave safe bowl, combine the marshmallows and coconut oil. Microwave on high for about 30 seconds. Add half of the tablespoon of cornstarch to your bowl and mix it in with a spoon. Keep stirring until the slime cools down enough to start kneading and playing with it! You can add more cornstarch to make your slime stiffer and more like putty.

The last step is to enjoy playing with your edible slime!

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Evergreen Trees Through the Seasons

12/22/2017

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As the earth orbits around the sun, most climates experience some fluctuations that separate the year into seasons. These changes affect almost all living beings - plants and animals alike! When it gets cold outside, we bundle up to keep warm while some other animals go into hibernation. Annual plants will grow and bloom when it’s warm and there’s plenty of sunlight, and they’ll die in the winter. Perennials are similar, but the rootstock (underground part of the plant) will regenerate new growth in the following spring and summer.

Trees are much larger plants, and are generally divided into two groups: deciduous trees and evergreen trees. Deciduous trees lose their leaves in the fall and enter a state of hibernation for the winter before regrowing their leaves from buds. The leaves of evergreen trees will stay green all year long, and are constantly being replaced as the cells age and die. While deciduous trees have evolved and adapted to better survive in cool/dry periods, evergreens were already pretty hardy and could withstand more harsh conditions without changing. This is why they stay green all year. For more information on leaves, check out our blog post about them from this May!

The largest subgroup of evergreen trees are conifers, which is Latin for “cone-bearer”. Not all evergreens are conifers, because in some climates (such as a tropical rainforest) plants like palm trees and shrubs shed and regrow leaves year-round. There are seven coniferous families, all of which have needle leaves and reproduce via cones.

Cones come in all different shapes and sizes, ranging all the way from the coulter pine’s 11 lbs to the Canadian hemlock’s one centimeter long cone. In order to reproduce, conifers have both male and female cones. The male cones are the only ones that release pollen, and thus are smaller than female cones and reside on the tree’s lower branches.

When it’s time to reproduce, the male cones release millions of tiny grains of pollen, which the wind carries up toward the female cones. Coniferous trees can be self-pollinated to create genetically identical offspring, or the wind could carry pollen from one tree to another. After pollen is released, the male cones don’t have any further purpose so they fall off and die. In the image below, cloud of pollen grains are released by the male cones of an evergreen!

The first step of fertilization begins with the pollination of a female cone. Next comes the appearance of pine seeds growing among the female cone’s scales; iIt can take up to two years after pollination for the cone to produce seeds! Some pine cones even have spines on the scales to dissuade birds from eating their seeds.

Test Your Knowledge!

The most common type of conifer in North America is the pine family (Pinaceae). This family include pines, spruces, firs, hemlocks, larches, and true cedars. You can go outside to collect random cones and try to find which type of tree they belong to!

Here are a few key differences:

Spruce cones grow from the center of a stem. The overlapping scales are paper-like and thin.
Pine cones also grow from a central stem. Some have spiny scales. The overlapping scales are woody and thick. Seeds are located at the scales’ base.
Fir cones grow upwards from closer to the tip of the stem. Scales overlap and feel papery and flexible. They often fall apart while still connected to the tree.
Hemlock cones are very small; only about one inch long. They grow from the tips of the branch and have thin, flexible scales.

For more information and helpful images, we recommend “Simple Keys for Identifying Conifers” by Playful Learning. Click here to visit their website!

References:

“Simple Keys for Identifying Conifers”. Playful Learning, playfullearning.net . Accessed on 12/6/17. https://home.playfullearning.net/resource/simple-keys-identifying-conifers-pine-family/

“Pollination by the Wind”. Newton’s Apple, newtonsapple.org.uk. Accessed on 12/7/17. http://www.newtonsapple.org.uk/pollination-by-the-wind/

Image Credits:

Hodan, George. “Evergreen”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net

Kratochvil, Petr. “Christmas Garland”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net

Moisset, Beatriz. “Pollen Flowing From a Pine Tree”. Released into the public domain under the Creative Commons Attribution-Share Alike 3.0 Unported license. Uploaded on 12/6/17 from commons.wikimedia.org

Kratochvil, Petr. “Cone and Needles Background”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net

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Turkey and Tryptophan

12/6/2017

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With the passing of Thanksgiving in both Canada and the United States, many families across the continent celebrated by gathering for a big meal - with turkey as one of the main dishes! Tryptophan is an essential amino acid found in turkey.

An amino acid that is essential means that the human body can’t produce it on its own, so we need to supplement our diet by eating food that contains the amino acid. Not only is it essential for humans, but for cats and dogs too - just don’t give them too much of your table scraps!

Does Tryptophan Make You Sleepy?

There has long been an urban legend that eating turkey - and the tryptophan it contains - will make you sleepy. This myth could come from a couple of different theories: the most prominent is that when you start digesting food, your parasympathetic nervous system kicks in. Unlike the sympathetic nervous system - which controls your “fight or flight” responses to certain situations - the parasympathetic nervous system is in charge of resting and digesting. Without any other outside stimulation or other priorities, your body is free to focus on recharging and digesting food. So when the parasympathetic nervous system takes over, you feel relaxed or sleepy while your digestive system gets to work.

The discussion of tryptophan and drowsiness comes up most often around Thanksgiving, when many people eat copious amounts of food - not just turkey! Eating a meal high in carbohydrates triggers the pancreas to release insulin, which stimulates the uptake of all amino acids but tryptophan. When this happens, there’s a higher concentration of tryptophan in the bloodstream. Now, tryptophan can be converted into serotonin and further metabolized into melatonin - the neurotransmitter that controls drowsiness. So in a way, eating lots of turkey could cause you to feel sleepy, but only if you eat even more carbohydrates with it.

Turkey isn’t the only food that contains this amino acid! In fact, pork chops, sunflower seeds, and parmesan cheese all have a greater concentration of tryptophan than turkey. And chicken has just as much, so you don’t need turkey to benefit from the tryptophan in poultry.

Test This at Home!

For this activity, you’ll need something you can use to take notes (such as a journal), about six ounces of turkey, and a 500 mg tryptophan tablet. On the first day, eat a meal that contains turkey and monitor your level of drowsiness in the journal. According to the article “How Much Tryptophan is in Poultry?” there’s about 270 milligrams of tryptophan in a three-ounce serving of light meat turkey, so six ounces would be pretty close to 500 milligrams.

The next day, take the tryptophan tablet and record how you feel again. Compare the notes and see if you can notice a difference!

References:

Busch, Sandi. "How Much Tryptophan is in Poultry?" SFGATE.com. Accessed on 11/24/17.

Image Credits:

“Structure of L-Tryptophan”. Released into the public domain. Uploaded on 11/24/17 from commons.wikimedia.org

Kratochvil, Petr. “Christmas Turkey”. Released into the public domain. Uploaded on 11/24/17 from publicdomainpictures.net

Mueller, Aline. “Sunflower”. Released into the public domain. Uploaded on 11/26/17 from publicdomainpictures.net

Frerichs, Lilla. “Carving the Turkey”. Released into the public domain. Uploaded on 11/26/17 from publicdomainpictures.net

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Gluten

11/17/2017

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For many people all over the world, bread is a major part of their diet. However, did you know that about 3 million Americans, or about 1% of the population, can’t digest it? These individuals have a genetic autoimmune disorder called celiac disease, which triggers the lining of the small intestine to be destroyed when someone eats food containing gluten.

What is Gluten?

Gluten is the general name for proteins found in grass-related grains, such as wheat or barley. It acts as a glue that holds food together and gives it shape. When we make bread, the flour we use most often comes from wheat. As we learned in our the first blog post in the Chemistry of Cooking series, wheat flour contains the proteins glutenin and gliadin, which form gluten when combined with water. As the bread dough is kneaded, the gluten proteins are uncoiled and become stretchy. It now has the texture of gum, and it traps the little bubbles of carbon dioxide from the yeast and prevents the gas from escaping, allowing the bread to rise.

As the dough continues to rise, the gluten becomes more stringy - like a very weak bubblegum! This is why bread doesn’t have a uniform solid texture; there are little air pockets that keep it nice and light. Before your bread is ready, the gluten has to harden for dough to become bread.

Gluten Alternatives

It’s important to note that unless you have celiac disease or any gluten sensitivity, gluten is not bad for you at all! But because some people cannot digest gluten, there has been high demand for gluten-free products. On their own, gluten-free flours don’t have the elasticity we want for dough, and typically produce a much denser product. To fix this, blends of different types of grains are used to create gluten-free flour mixes with a more versatile consistency that will produce a similar product as wheat flour.

Gluten-free flours you might find at a grocery store are all made with different mixtures that vary widely from brand to brand. They might contain the flour of rice, tapioca, sorghum, coconut, potato starch, or buckwheat – just to name a few! These flours might also contain nut flours, made from very finely ground almonds or other nuts.

A frequently used binder, xanthan gum, is added to gluten-free flour mixes to give the dough some elasticity and make it easy to use right out of the bag. Because the base ingredients for gluten-free flour can be very different, different brands can produce varied results in baked goods, giving a recipe a completely different taste and texture.

Which Flour Do You Like Best?

Now that we know more about what gluten does, we can experiment with different types of flour to make bread!

Unbleached all-purpose flour has about 10% protein (gluten), and is the most common flour used in baking. You can also purchase all-purpose gluten-free flour from a mixture of different sources.
Almond flour is gluten-free, and is very absorbent, so you only need to use ¼ of the flour mixture in your recipe.
Barley flour has very low gluten, so when you make bread with yeast, you’ll want to use a mixture of ¾ barley flour and ¼ all-purpose flour.
Bread flour is made from hard, high-protein wheat. It has more gluten strength and protein content than all-purpose flour, making it the best candidate for yeast bread.

You can use these different flour types to make bread, and decide which tastes the best to you! Here’s a recipe for bread with almond flour to get you started. Otherwise, use the above paragraph for a guideline as to how much flour you need.

Experiment with different types of flour, and see how your bread turns out!

The recipe below was taken from tasteofhome.com, and is one of their most popular bread recipes (https://www.tasteofhome.com/recipes/basic-homemade-bread). The only ingredient we’ll be changing is the type of flour, so we can see how the amount of gluten affects the texture of the bread.

Ingredients:

1 package (¼ oz) active dry yeast
2 ¼ cups warm water
3 tablespoons sugar
1 tablespoon salt
2 tablespoons oil
6 ½ cups flour (all-purpose, bread, and gluten-free)

Dissolve the yeast in warm water--this is called “blooming”, or waking the yeast up. Add sugar, salt, oil, and three cups of flour (remember, you are making three different loaves!). Beat with a mixer (with dough hook attachment preferably) until all ingredients are well combined. Add the remaining flour ½ cup at a time until a dough forms.

Place the dough on a floured surface and knead until it’s smooth and elastic--about 5-10 minutes (this may not be as evident with the gluten-free dough). Then put the dough in a large bowl coated with oil - make sure to turn the dough to coat all sides with oil! Cover the bowl with plastic wrap and let it rise for about 1.5 - 2 hours.

Punch down the dough and transfer it again onto a lightly floured surface. Divide the dough in half and shape the pieces into loaves. Place each loaf in a greased 8x4 inch loaf pan and cover with plastic wrap sprayed with nonstick cooking spray. Now you can let it rise until it’s doubled in size - about 45 minutes.

Bake the bread at 425℉ for 15 minutes, and then lower the temperature to 375℉ to continue baking for another 15-20 minutes. The bread should be golden brown and sound hollow when the bottom of the pan is tapped. Place the bread on a wire rack and let it completely cool before you take a bite!

References:

“Different Types of Flours”. What’s Cooking America, whatscookingamerica.net. Accessed online on 11/10/17.
https://whatscookingamerica.net/Bread/FlourTypes.htm

“Basic Homemade Bread Recipe”. Taste of Home, tasteofhome.com. Originally published as Basic Homemade Bread in The Taste of Home Cookbook 2006, p452. Accessed online on 11/10/17.

Image Credits:

Di Nucci, Gustavo. “Give Bread 2”. Released into the public domain. Uploaded on 11/9/17 from publicdomainpictures.net

Kratochvil, Petr. “Raw Dough”. Released into the public domain. Uploaded on 11/10/17 from publicdomainpictures.net

Revel, Richard. “Wheat Field”. Released into the public domain. Uploaded on 11/9/17 from publicdomainpictures.net

Libby, Junior. “Sliced Bread”. Released into the public domain. Uploaded on 11/9/17 from publicdomainpictures.net

“EleanorD Kneading”. Released into the public domain. Uploaded on 11/10/17 from commons.wikimedia.org

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Making Caramel Apples in the Microwave

10/30/2017

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Every day, we are in contact with a type of energy called electromagnetic radiation. Most of the time it’s in the form of visible light. But did you know that all visible light comprises just a small portion of the electromagnetic spectrum? Radiation is created when an atomic particle (such as an electron) is accelerated by an electric field, causing it to move. This makes a wave in a bundle of light energy, called a photon. The length of these waves classifies the type of radiation produced!

Introduction to Radiation

There are seven sections on the electromagnetic spectrum, ranging from very long wavelengths to very short wavelengths. In this lesson we’ll be focusing on microwaves, but the other types are as follows:

Radio waves have the longest wavelengths on the spectrum, and are used for communication - like radio programs and television! Microwaves come next on the spectrum. Sunlight is comprised of infrared radiation, visible light, and ultraviolet rays. Although we can’t see infrared light, we can feel the heat if we’re close enough to the source! Visible light is comprised of all the wavelengths between 390 and 700 nanometers, which are the colors we can see. It’s the only type of electromagnetic radiation that the human eye can sense.

UV rays are harmless in short periods of time. However, many of us like to go outside in the summer and bask in the sun’s rays. We put on sunscreen to protect our skin from the damage ultraviolet light can potentially cause. The more harmful types of radiation on the electromagnetic spectrum are X-rays and gamma rays. This is why we wear lead when being scanned by an X-ray machine, and why gamma rays are used to destroy some kinds of cancer cells.

How Microwaves Work

Your typical household microwave is able to convert a standard 120-volt electrical outlet into 3000+ volts of power to generate waves of radiation that will heat your food. Inside a microwave is a part called the magnetron, which is what boils off electrons that are whirled around by magnets to create microwaves at a specific frequency. An antenna then transfers those waves into the open chamber where your food is waiting to be cooked.

The microwaves will bounce around the cooking chamber until they penetrate the food and “excite” the polar molecules within your food. In many cases, the polar molecules are water molecules!

When the molecules vibrate, they twist and turn, rubbing up against each other to create friction. This friction is what creates the heat that will cook your food. Because glass, plastic, and ceramics don’t have many of the molecules microwaves look for, the plate or bowl holding your food isn’t cooked. Sometimes the hot food does make the bottom of your plate warm, so always be careful when removing food from the microwave!

One great thing about these appliances is that you don’t have to worry about the radiation damaging anything outside your microwave. Household microwaves have a metal plate with holes in it that are small enough to prevent the waves from escaping, but it still allows you to see the food inside.

Homemade Caramel Apples
Apples are a good fruit to eat all throughout the year, but this sweet treat is great in the fall! Many fairs or spooky events serve caramel apples to their visitors, but why wait when you can make them at home in the microwave? This recipe from AllRecipes.com calls for only a few ingredients: six apples, six craft sticks, some butter, a 14-ounce package of cooking caramels, and two tablespoons of milk.

First, you’ll want to remove the stems and stickers from the apples (twisting is a good way to get the stems off). Press a craft stick into each apple and set aside with a buttered baking sheet.

Using a microwave safe bowl, cook the caramels and milk for two minutes in your microwave. Stir it once and let it cool for a few seconds so you don’t burn yourself. Quickly roll each apple in the caramel sauce until it’s well coated. Then you can place the apple on the prepared baking sheet and wait for the caramel to set. Enjoy!

References:

Fischetti, Mark. “How the Microwave Works.” Scientific American, scientificamerican.com. Accessed on 10/27/17.

Caramel Apples Recipe: http://allrecipes.com/recipe/21130/caramel-apples/

Image Credits:

Siedlecki, Piotr. “Wireless Logo”. Released into the public domain. Uploaded on 10/27/17 from publicdomainpictures.net

Microwave and molecule images property of Discovery Express Kids LLC.

“Coated Caramel Apple”. Released into the public domain under the Creative Commons Attribution 2.0 Generic License. Uploaded on 10/28/17 from commons.wikimedia.org

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