First, the chemicals that accompany the day-salt and iodine compounds.
We know that the main component of salt is sodium chloride, which is the most commonly used condiment in people's lives. But its function is not only to increase.
The flavor of added food is the basic component of human tissues, which plays an important role in ensuring normal physiological and biochemical activities and functions in the body. The functions of Na+ and Cl- in vivo are closely related to K+ and other elements. Its main function is to control the electrolyte balance in cells, tissue fluid and blood, so as to maintain the normal circulation of body fluids and control the acid-base balance in the body. Na+, K+, Ca2+ and Mg2+ are also helpful to maintain the appropriate stress level of nerves and muscles. NaCl and KCl play a role in regulating the proper viscosity or consistency of blood; The acids that begin to digest certain foods in the stomach and other digestive compounds in gastric juice, pancreatic juice and bile are also formed by sodium and potassium salts in the blood. In addition, appropriate concentrations of Na+, K+ and Cl- also play an important role in the physiological process of retinal response to light. In addition, gargling with light salt water can not only treat and prevent oral diseases such as sore throat and swollen gums, but also prevent colds. (See "alkali metals" in senior one chemistry)
Iodine-containing compounds such as potassium iodide, sodium iodide and iodate are important reagents in the laboratory. In food and medical treatment, they are also important nutrients and drugs, which play an important role in maintaining human health. Iodine is an essential trace element for human body and an important component of thyroid hormone. In normal people, * * * contains iodine 15 mg ~ 20 mg, of which 70% ~ 80% is concentrated in the thyroid gland. Iodine in human body exists in the form of compound, and its main physiological function occurs through the formation of thyroid hormone. Therefore, the physiological function and important role of thyroxine are directly related to iodine. Iodine deficiency in human body can lead to a series of biochemical disorders and physiological dysfunction, such as endemic goiter, infant growth and development stagnation, mental retardation and so on. China is a serious iodine deficiency area in the world, and there are about 400 million people in China who are iodine deficient. The government has also taken some measures, such as providing iodized salt and other foods (such as eggs with high iodine content), iodizing well water and eating iodine-rich seafood, among which iodized salt is the most convenient and effective. 1991March, our government solemnly promised the international community that iodine deficiency disorders would be eliminated in Chinese mainland in 2000. (See "Halogen Elements" in Senior One Chemistry)
Second, why do raw persimmons have astringency?
No matter who was born in the north or the south, people will have such a life experience: persimmons that are red as fire on persimmon trees are still inedible. At first taste, it is still very astringent. Is this persimmon not fully ripe? Yes, but if persimmons are fully ripe, it is not good for people to pick, transport and store them. Therefore, people often pick the persimmon when it turns red, and put it for a while, and it becomes a sweet and fragrant persimmon.
So, why does persimmon have astringency?
It turns out that this is because raw persimmons contain tannin (also called tannic acid), which makes persimmons astringent.
In order to get rid of the astringency of raw persimmons, people have come up with many ways in their constant life practice. Some people cover persimmons layer by layer with straw or pine needles, or bury persimmons in leaves with pears. After a period of time, the astringency of persimmons is gone. Some people directly scald persimmons with hot water, and the astringency of persimmons is naturally removed. Now people have adopted the "carbon dioxide deastringency method", which is actually a summary of people's past life experience. People seal persimmons in a room to increase the indoor carbon dioxide concentration and reduce the oxygen concentration. In this way, persimmons can't breathe normally, but breathe in the absence of oxygen. In the case of anoxic breathing, organic substances such as acetaldehyde and acetone will be produced inside raw persimmon. These organic substances can turn water-soluble tannins into water-insoluble substances, so persimmons are no longer astringent, but sweet and fragrant.
If you also have a few raw persimmons that want to "get rid of astringency", you can put them in plastic bags and tie them tightly. Generally, the astringency can be removed in a few days.
Third, "smells bad and tastes good"
Stinky tofu is a kind of favorite food. "Smelling stinky and eating fragrant" is the unique flavor of stinky tofu. Stinky tofu tastes better.
Students who have never eaten stinky tofu can't imagine why such stinky tofu has so many diners. If you hold your nose and bite the bullet and try bravely, you won't ask why.
It turns out that stinky tofu stinks, but it is delicious. No wonder its smell can't stop.
Stinky tofu is made by processing soybeans into tofu with less water content and then inoculating Mucor seeds for fermentation. Stinky tofu is produced in summer, when the fermentation temperature is high and the protein in tofu is completely decomposed. The sulfur-containing amino acids decomposed by protein are further decomposed to produce a small amount of hydrogen sulfide gas. Hydrogen sulfide has a pungent smell, so stinky tofu smells strong.
And because protein in tofu is decomposed more thoroughly, stinky tofu contains a lot of amino acids. Many amino acids taste delicious. For example, the ingredient of monosodium glutamate is an amino acid called glutamic acid. So stinky tofu tastes extremely delicious and smells abnormal.
Stinky tofu is a patented product of China! Many famous foods are related to stinky tofu. For example, fried stinky tofu is a particularly famous snack.
Fourth, vinegar (acid)
The chemical name of vinegar is acetic acid, and the molecular formula is CH3COOH. Vinegar is not only a condiment, but also has many uses: 1. When cooking vegetables, adding vinegar not only tastes delicious, but also protects vitamin C in vegetables (because vitamin C is not easy to be destroyed in acidic environment). 2. When cooking ribs, chicken and fish, if you add a little vinegar, a large amount of calcium and phosphorus in bones can be dissolved in soup, thus greatly improving the absorption rate of calcium and phosphorus in human body. 3. People suffering from low-acid gastropathy (low gastric acid secretion, such as atrophic gastritis) can not only increase their appetite, but also treat diseases if they are often seasoned with a small amount of vinegar. When the fish is not fresh, cooking with vinegar can not only remove the fishy smell, but also kill bacteria. Vinegar can be used as a good medicine to prevent dysentery. Dysentery bacteria will die as soon as they encounter vinegar, so being jealous in the summer when dysentery is prevalent can increase the effect of killing dysentery bacteria in the stomach. 6. Vinegar can also prevent influenza. Close indoor doors and windows, pour vinegar into the pot and boil until it is dry, which can kill germs. 7. Drop a drop of vinegar when you shine your shoes to make them bright and lasting. 8. Copper and aluminum are worn out. After cleaning with vinegar, the luster can be restored. 9. 20 minutes before killing chickens and ducks, pour some vinegar on the chickens and ducks, and pluck the hair easily. 10, the clothes were stained with juice, soaked in vinegar and rubbed off. 1 1. Soaking the scale in the thermos bottle with vinegar can achieve the purpose of scale removal. 12, towels are prone to mildew and odor in summer. Washing towels with a small amount of vinegar can eliminate the odor. (See "Derivatives of Hydrocarbons" in Senior Two Chemistry)
Five, non-static drugs-cigarettes
This paper introduces the structure, properties and harm of harmful components produced in the process of smoking from the chemical point of view. The harmful substances produced by cigarette ignition can be roughly divided into six categories: (1) aldehydes, nitrides and olefins, which have irritating effects on respiratory tract. (2) Nicotine can stimulate sympathetic nerve and cause intimal injury. (3) Amines, cyanide and heavy metals are all toxic substances. (4) Radioactive substances such as phenylpropyl pyrene, arsenic, cadmium, methylhydrazine and aminophenol. These substances are carcinogenic. ⑤ Phenolic compounds and formaldehyde, etc. It has the effect of accelerating cancer. (6) Carbon monoxide will reduce the ability of red blood cells to transport oxygen to the whole body. Recent research by Japanese scholars shows that smog also contains the most toxic compound "dioxin" among known substances. They can cause and aggravate various diseases, such as cancer, pneumonia, tracheitis, hypertension, hyperosteogeny, various cardiovascular and cerebrovascular diseases, asthma, infertility and so on. According to the information provided by the World Health Organization, about 654.38+0 billion people worldwide die of smoking-related diseases every year. Teenagers are in the period of growth and development, respiratory mucosa is easy to be damaged, and smoking is more harmful. According to the survey, the incidence of lung cancer among people who started smoking under the age of 15 was 17 times higher than that of non-smokers. Therefore, China's "Code for Primary and Secondary School Students" stipulates that students are not allowed to smoke. (The knowledge content runs through the organic matter in senior two chemistry)
Sixth, don't let the color confuse your eyes.
We often see gold fonts or patterns on plastic diaries, binders and other items. This kind of gold lettering or pattern is ironed with gold powder. Is this gold powder made of gold? Of course not. Gold is so expensive that people will never use it to grind powder to decorate ordinary products. So, what is gold powder made of?
It turns out that the gold powder is made of copper-zinc alloy-proud silver copper. It's the same color as gold. People made brass in the Han dynasty, which was later called "fake gold", and the law at that time explicitly prohibited its use. We know that copper is purplish red, zinc is silvery white, and their alloy brass is as shiny as gold in Huang Chengcheng. Gold powder is made by mashing and polishing a thin piece of brass and a small amount of lubricant. Gold powder is widely used in paint and ink.
Similarly, silver powder used in paints and inks is not made of silver. Silver powder is made of aluminum, which is very cheap and has the same silvery white luster as silver. Aluminum powder is light in weight, stable in air, strong in light resistance and strong in light reflection ... This series of advantages makes aluminum powder win the title of "silver powder".
There are two ways to make aluminum powder. One method is to mix pure aluminum flakes with a small amount of lubricant and then mechanically mash them. Another method is to melt pure aluminum into liquid (the melting point of aluminum is low, only 660℃) and then spray it into fine aluminum powder.
Seven, the right-hand man in life:
(a), remove the stains on the clothes:
1, sweat stains: Method 1: Soak the clothes with sweat stains in 10% salt water for a while, and then wash them with soap. Method 2: Add a small amount of urea [(NH4)2CO3] and a small amount of edible alkali [Na2CO3 or NaHCO3] into a proper amount of water, stir and dissolve, then soak the clothes with sweat stains in it for a period of time, and then rub them repeatedly.
2. Oil stains Drop gasoline or alcohol on the oil stains, and the oil stains will disappear after the gasoline (or alcohol) volatilizes.
3. Blue ink stain: Method 1: Add a small amount of carbon amine [(NH4)2CO3] and a small amount of edible alkali [Na2CO3 or NaHCO3] into a proper amount of water, stir and dissolve, then soak the clothes stained with blue ink in it for a while, and then rub it repeatedly. Method 2: soak the part stained with blue ink in 2% oxalic acid solution for a few minutes, and then wash it off with detergent.
4. Because blood stains contain protein, protein is not easy to dissolve when it is heated, so you can't wash blood stains with hot water. Method 1: soak the bloodstained part in hydrogen peroxide or bleaching powder water for a while, and then scrub it. Method 2: Chop the radish, sprinkle with salt and stir well. After ten minutes, squeeze out the radish juice, soak the bloody part in the radish juice for a while, and then rub it.
5, juice stains The newly infected juice stains are soaked in salt water and washed with soap. If it is a long-term infection, you can use the first method to wash sweat stains.
6. Rust spot: Add a little oxalic acid to hot water, stir until all oxalic acid is dissolved, soak the rusty spot in oxalic acid solution for ten minutes, and then scrub it with soap.
7. Tea stains Soak the parts with tea stains with saturated salt water, and then wash them with soap.
(2) Clever descaling
1, put the empty kettle on the fire and boil the water with scale. When you see cracks in the scale at the bottom of the kettle, take it off quickly and put it in cold water. The scale at the bottom of the kettle will fall off due to thermal expansion and contraction. 2. Put a group of mask cloth in the pot of boiling water, and the scale will be absorbed by the mask cloth, so it is not easy to scale on the pot. 3, the boiling water in the pot has scale, you can put some vinegar, add water, cook for a while, and the scale can be removed. 4. When boiling water in aluminum pot, put a spoonful of baking soda and boil it for 10 minute, and the scale can be removed.
Eight, laxative-phenolphthalein
Anyone with a little knowledge of chemistry knows that dropping one or two drops of a certain solution into an aqueous solution of sodium hydroxide will immediately show a bright red color. This is the famous indicator-phenolphthalein. If a certain amount of sulfuric acid is added to the red solution, the red solution will become colorless again.
Phenolphthalein is one of the most commonly used acid-base indicators, which is soluble in alcohol when used. It will turn red when it meets alkaline solution, but it is still colorless in neutral or acidic solution.
But people who have studied chemistry may not know that phenolphthalein is still a good medicine for doctors! In medicine, phenolphthalein is a laxative. Phenolphthalein can gently stimulate intestinal wall, enhance intestinal peristalsis and promote defecation, which is very effective for habitual constipation. The "Fruit Guide" contains phenolphthalein.
Nine, eggs, milk poisoning first aid
Maybe you have heard that eggs, milk and soybean milk can be used as first aid drugs for poisoned patients. What is the reason?
Eggs, milk and soybean milk are nutritious and contain a lot of protein. Protein has a characteristic that heavy metal ions, such as mercury and aluminum, will precipitate. When heavy metal ions enter the human body, protein, which constitutes human organs and blood, will precipitate and lose its function, leading to poisoning. At this time, after giving patients milk, raw egg white and soybean milk, protein rich in food will interact with heavy metal ions, thus reducing the toxicity of poisoning. At the same time, these foods also provide nutrition for patients who are poisoned and weak, and help patients recover.