Subtitles section Play video Print subtitles It's AumSum Time How do miracle fruits work? By performing miracles. No. Miracle fruit is a red berry also known as Synsepalum dulcificum. The fantastic quality about this berry is that after eating it. Acidic foods which should be sour, taste sweet. The secret behind this is a protein called Miraculin found in these fruits. However, experts are not sure how miraculin actually works. But there are three popular theories. First theory states that miraculin temporarily suppresses sour taste receptors. Hence, when we eat acidic foods, they dont taste sour. Second theory states that miraculin rewires the sweet receptors. Such that they begin to identify acids as sugars. Thus making sour foods taste sweet. Whereas third theory states that acids cause miraculin to change its shape. Causing it to bind to the sweet receptors more strongly. Making them over activated, producing a sweet taste. Neutralization reaction. How to treat a bee sting? Hey. Hold On. Do not go near that honeycomb. Please listen to me. It is quite dangerous. Fine. Go ahead. See, I told you. Okay. Now, do not worry. Put this baking soda solution on the bee stung area. You got some relief, right? Do you know why you got relief? This happened because a neutralization reaction took place. When we applied baking soda on the stung area. The venom of a honey bee contains formic acid. When it stings us, it injects that acid into our skin. Formic acid causes immense pain and irritation. However, when we apply baking soda solution, which is a mild base, on the stung area. It neutralizes the formic acid and cancels its effect. As a result, the sensation of pain and irritation decreases and we get some relief. Such a reaction between an acid and a base is called neutralization. In neutralization, both acidic and basic solutions neutralize the effect of each other. The nature of both acids and bases gets destroyed. Hey, Wait. What are you doing? Do not tease that insect. It is not a honey bee. It looks similar to a honey bee but it is a bit longer. It is called a wasp. At least this time listen to me. Okay. Don't listen and bear the consequences. Applying the baking soda is not going to help. See, nothing is happening. I will tell you what to do. Pour this vinegar on the stung area, you will get some relief. Why do you think the baking soda solution did not help in this case? Earlier, in case of the honey bee, we learnt that its venom is acidic. Hence, baking soda, being a basic solution helped to neutralize the effect. Now, in case of a wasp, the nature of its venom is basic. When it stings us, it injects that venom into our skin. This venom causes us pain and itching. Now, baking soda is also a basic solution. Hence, it will not provide any sort of relief. However, when we pour vinegar, which is a mild acid, on the stung area. The acid, that is, vinegar and the base, that is, the wasp's venom get neutralized. As a result, the sensation of pain and itching decreases and we feel better. Metals and acids. Why is curd not stored in copper containers? Hey wait. What are you doing? Do not eat that curd. It was stored in a copper container. Please listen. Fine, then bear the consequences. I had warned you. Do you know why this happened? This happened because curd contains lactic acid in it. When curd is stored in containers made up of metals like copper or brass. The lactic acid present in it, reacts with the metal and forms metallic salts. These metallic salts are harmful. They make the curd unfit for human consumption. Therefore, to prevent metals from reacting with acids present in food. The metal containers are coated with a thin layer of tin. Tin is also a metal. However, it does not react with acids as rapidly as other metals do. Thus keeping the food in the container safe. Sublimation. Why do mothballs disappear over time? You have a nice collection of clothes. But have you kept mothballs to protect them? Yes. I had kept them a few months back below these clothes. Oh no. Where did the mothballs go? I had placed them right here. Did you steal them? No, no. I have not stolen anything. Mothballs disappear over time. Do you know why? It is because of a process called sublimation. During sublimation, a solid on heating, converts directly into vapor. Without passing through the intermediate liquid state. Do not lie. How is that even possible? See, I also hid a burger here many days ago. It did not disappear. Oh gross. Just throw that burger in the dustbin. Not all substances sublimate. Mothballs are made up of naphthalene. Naphthalene has very weak intermolecular forces. Because of these weak forces, the mothball which is made up of naphthalene sublimates. It changes its state from solid to vapor. Now, this vapor is either absorbed by the fabric or it escapes into the atmosphere. Causing the mothballs to disappear over time. Wavelength. Why red is used as a danger signal? Oh well, becasue my teacher said so. As usual, you are wrong. The major reason for red to be used as a danger signal is its wavelength. Yes, I know. Wavelength is the distance between two sea waves. No. In the wave theory of light, The distance between successive crests or troughs is called wavelength. Longer the wavelength, lesser will be the scattering of light. Now, among the colors of visible light, red has the longest wavelength. Hence, it is least scattered by the atmospheric particles. As a result whether it is fog or smoke, red light passes comparatively easily through them. Thus, it can be seen from maximum distance. Making red color the right choice to convey any danger. Auroras. Why are auroras formed? Maybe because the earth forgets to switch off the lights. No. Let me explain. Our sun is a giant burning star. It expels tons of solar wind into space. Solar wind consists of super hot charged particles which are fatal. So, should we use a big umbrella to protect ourselves from these particles? No. The earth's magnetic field acts like a shield and protects us. Its field lines appear to emerge from the south pole and merge into the north pole. Now, when the charged particles hit our magnetic field, most of them get deflected. However, some of them flow along the earth's magnetic field lines to the poles. Thus reach our upper atmosphere. Here, these particles collide with oxygen and nitrogen. This causes them to give off various colors of light which are called auroras. Human bones. How does a bone heal? Simple, by a bandage. No. Bones are one of the most important parts of our body. They not only provide structural support but also produce red blood cells. What? Our bones produce red blood cells? Absolutely. Hence, when we crack or break a bone, it is very important to heal it. In the healing process, cells called chondrocytes produce collagen which forms cartilage. This cartilage bridges the gap between the broken bones, thus producing a soft callus. Then, special cells called osteoblasts create a hard bony callus using collagen. Minerals like calcium and phosphorus, thus forming our new bone. However, this new bone is irregular in shape. Hence, cells called osteoclasts start remodelling the bone. Resulting in the formation of bone similar to the original shape. Dandruff. Why do we get dandruff? Tearing of pages. No. Dandruff is a condition in which our scalp sheds skin cells in the form of white flakes. A yeast called Malassezia globosa, is one of the mostly accepted reasons for causing dandruff. What a classy name it has. Indeed. Malassezia globosa is naturally present on our scalp. It feeds on sebum and releases oleic acid. Now, some people are sensitive to this oleic acid. When it penetrates into the upper layers of their skin, it causes inflammation. Hence, in response to this inflammation. Their skin sheds a large number of skin cells at a higher rate. These cells then join together forming white flakes, thus causing dandruff. Why do we stretch in the morning? So that we can sleep for two more hours. No. Wait, I will explain. When we wake up in the morning, we yawn and stretch our arms and legs. This coordinated yawning and stretching is referred to as pandiculation. I thought it is referred to as calculation. Just listen. When we are asleep, we do not perform any activities. Hence, our heart rate becomes slow and the blood flow is decreased. Also, as many people lie in the same position for long hours. Their muscles become stiff and tight. Thus, a good stretch in the morning awakens our body. It brings our heart rate back to normal, improving the blood flow to various body parts. Stretching also loosens and realigns our stiff muscles. Making them more flexible and ready for the day ahead. Why does hot air balloon float? Because it has invisible wings. No. It is because of density. Density is the measure of mass present per unit volume. Lesser the density, lighter will be the object. Now, density varies with temperature. Oh. It is so complicated. Alright. I will explain. When a hot air balloon is on ground. The air inside and outside the balloon is of same temperature and density. However, when we turn on the burner of the balloon. The air inside the balloon starts getting hot. The molecules of air move faster and spread apart, taking up more space. Hence, the air inside the balloon becomes less dense than the air outside. As less dense air is lighter, the hot air balloon rises and thus, begins to float. Why does airplane food taste bad? I do not know. Wait, I will explain. Our ability to perceive taste is affected by a few factors such as humidity, air pressure, etc. In an airplane, the humidity is less as compared to that on the ground. This makes the air in the airplane quite dry. Also, to maintain the air pressure inside and outside the airplane. The air pressure inside it is decreased. Decreased air pressure and dry air, dries our nose and mouth. Dry nose cannot properly smell odors. Yes. I am not abe to smell the burger. Now, smell of food helps us to understand the flavor and ingredients of the food. Thus, the food which we cannot smell properly appears unappealing. Also, dry mouth reduces the sensitivity of our taste buds. As a result, we cannot perceive the taste of food properly. Why do dogs lick their wounds? Dogs including animals like cats, chimpanzees, rodents, etc. Do not have access to a proper medical treatment. Hence, a little licking helps to heal and clean the wound. What? But how? When dogs lick, they apply saliva on their wounds. This saliva has antiviral and antibacterial compounds like an enzyme called lysozyme. Lysozyme destroys cell walls of certain bacteria and helps kill them, thus preventing infection. The saliva also contains a protein called tissue factor. Which promotes blood clotting and thus stops bleeding. Besides this, licking also removes dirt from the wound. So, dogs should always lick their wounds. No.