What is the biological reason why peppers are spicy?

According to Darwin's theory of evolution, variation is the differentiation of organisms, and natural selection is the driving force of biological evolution. Variation produces different traits, and through natural selection, those varieties with unfavorable traits are eliminated, the favourable traits are retained, and the species further adapts to the environment, which is evolution. Native to Mexico and South America, chili peppers have a "spicy"** taste like capsaicin, which causes a burning sensation in the nerves.

The so-called "spicy" is different from other tastes such as sweet and sour that we usually feel, and it is not strictly a taste, but a burning sensation. The vast majority of mammals experience intense discomfort with this burning sensation caused by capsaicin. <>

For plants, it is necessary to ensure the survival of the seeds, and at the same time to spread the seeds to as wide a region as possible, so as to avoid the seeds from clumping together to compete for sunlight and nutrients, and to avoid extreme conditions such as drought and flooding in one area, and to destroy all the seedlings in one nest. Some plants rely on their own abilities to accomplish this, such as dandelions, which make seeds flutter in the wind; Some plants use other creatures for this purpose, such as Xanthium, which has many hooked spines on its fruit that can hang on the hair of passing animals and wander around; There are also many plants that have taken a "bribe" approach to sowing seeds, the most common being peaches, apricots and cherries, their peels are sweet and juicy, but the seeds are protected by hard kernels, and many animals are attracted by the peels, and after eating the peels, they discard the kernels at will, unintentionally helping it to complete the sowing. Wild peppers are seeded with a strategy similar to that of peaches.

Maybe you have to say: horse eggs, peppers are so spicy, who will be as eager to help it sow seeds as eating peaches, fall! Don't worry, we have to solve this puzzle and first understand why chili peppers make you feel spicy.

Although chili pepper has long replaced dogwood and peppercorns as the representative of "pungency" in the six flavors, strictly speaking, spicy is not a taste, but a feeling: chili pepper contains an alkaloid called "capsaicin", which can bind to the vanillin receptor subtype 1 (VR1) of our sensory neurons in mammals, resulting in a burning sensation, which is what we call "spicy". But for birds, they lack receptors that are sensitive to capsaicin, so they don't feel spicy.

It can be seen from the figure: A represents the cell wall, B represents the cell membrane, E represents the chloroplast, C represents the nucleus, F represents the vacuole, and D represents the cytoplasm, so the figure is a schematic diagram of the structure of plant cells (1) [a] The cell wall is the outermost transparent thin wall of the plant cell, which has the role of protecting and supporting the cell (2) The B cell membrane can control the entry and exit of substances in addition to the protective effect (3) [F] The cell fluid in the vacuole dissolves a variety of substances, such as the spicy substance in the cell vacuole in the pepper (4) There are e chloroplasts in plant cells, which contain chlorophyll, which makes plants green (5) Compared with plant cells, animal cells have cell membranes, cytoplasm, nuclei and mitochondria in the same points, and plant cells also have cell walls, chloroplasts and vacuoles at different points Therefore, the answer is: (1) a; Cell wall; Protection and support (2)b; Cell membrane (3)f vacuole; Cell sap (4) e-chloroplast (5) animal cells; Cell wall; Vacuole; Chloroplast.

First of all, the fruit is mainly made up of the peel and the seeds in the middle. Many plant fruits are indeed delicious, but the only thing that is delicious is the skin. The delicious peel attracts animals to feed, while the seeds are coated with a hard and indigestible seed coat, making them difficult to digest.

The seeds are thus sown almost unharmedly with the excrement. This explains what you mean by walnuts. The walnuts we saw no longer had their skins, only seeds and seed coats, so they weren't as tasty.

Second, delicious peels are just one strategy in evolution. There are many strategies that plants use to sow seeds, not just the one you mentioned. Dandelions and willows, for example, have ciliated seeds that can be scattered by the wind and do not need the help of animals.

For example, Xanthium, whose seeds are coated with barbs, can be hung on cattle and sheep and other mammals and thus spread far away. Another example is spray melon, its peel loses moisture and becomes fragile after ripening, and the seeds are squeezed and ejected by internal pressure. Similarly, tropical fruits such as durian and coconut are not strategies.

Common tropical plants tend to be very close to the sea, and their fruits may be carried away by the tide as soon as they ripen and land, so these fruits are spread by seawater as a medium. Well, what durian and coconut have to do is make the fruit less dense than seawater so that it can float on the water. <>

The pungent flavor of chili peppers comes from the capsaicin molecule, which protects the pepper fruit from fungus erosion and rodent nibbling, and it also does not hinder birds from spreading the fruit's seeds. But this begs a new question: if spicy is so beneficial, why aren't some peppers spicy?

In a study published in the Proceedings of the Royal Society on December 21, 2011, researchers at the University of Washington in the United States gave us an answer.

David. Harker is a graduate of the University of Washington and is currently a postdoctoral fellow at Indiana University. He has studied a wild pepper that grows in Bolivia.

Huck and University of Washington ecologist Tukesbury and colleagues found that the wettest places in their study area were only spicy peppers. In the driest places, there is both, but only 15 to 20 percent of the plants produce spicy fruit.

The researchers collected spicy and non-spicy peppers from three of the study areas where precipitation and plant species had been measured. They sow seeds in the lab, simulating a moist and dry environment, giving the plants enough water and not enough water, respectively. The researchers found that both non-spicy and spicy plants thrive well when they have plenty of water, and that spicy plants produce as many seeds as non-spicy plants.

However, because Bolivia's moisture-loving fusarium-like fungi attack peppers, non-spicy plants are more fragile and less likely to survive. That's why spicy chili peppers dominate Bolivia's humid regions, Huque and colleagues concluded.

But when the plant is grown in a dry environment, the seeds of the spicy plant are only half that of the non-spicy plant. This is due to the fact that the plant's water is expelled through tiny stomata on the leaves and stems. During the day, plants pass through the stomata and release oxygen that absorbs carbon dioxide, but this gas exchange leads to water loss.

Since the stomatal density on the gas leaves directly affects the loss of water, the research team compared the stomatal density on 30 spicy and non-spicy peppers of similar age and height.

They found that stomatal density was 40% higher in spicy plants than in non-spicy plants. After crossing the two types of plants, the research team found that the stomatal density of the spicy hybrid pepper was still higher than that of the non-spicy hybrid pepper. Since spicy plants lose more water, they don't have many seeds.

In a dry environment, the fungus fusarium is no longer a big problem for non-spicy peppers, and because it retains more water and produces more seeds, these plants can thrive in a dry environment and outperform their pepper counterparts.

Chili pepper is from "Illustrated Examination of Plant Names"; "Drug Test": Spicy eggplant, all kinds of different, into the medicine only take slender as ivory, and like a human finger. It can be used as food.

Zunyi Mansion Chronicles": Pepper, there are several kinds of shapes. Long and slender like horns, the name of the horn sea pepper, small as the tip of the pen, the clump knot pointed up, the name of the pepper, the two kinds of particularly spicy.

A kind of flat round, red or yellow color, not very spicy taste, the name persimmon pepper.

Pepper is an annual or perennial herb with roots, 40-80cm tall. The leaves are alternate, and the apical nodes of the branches do not elongate into twins or clusters;Leaves oblong-ovate, ovate or ovate-lanceolate, 4-13 cm long, wide, entire, apex pointed, base tapering. The flowers are solitary, drooping;Calyx cup-shaped, inconspicuously 5-toothed;Corolla white, lobes ovate;Stamens 5;Pistil 1, ovary superior, 2-chambered, few 3-chambered, columella linear.

The berries are long finger-shaped, with an apex tapering and often curved, green when unripe, red, orange or purplish-red when ripe, and spicy in taste. The seeds are numerous, flattened kidney-shaped, pale yellow. The flowering and fruiting period is from May to November.

There are many varieties of chili peppers, including Da Hong Pao, Da Jin Bar, Erjin Bar, Chaotian Pepper, Rice Pepper, Horn Sea Pepper, Seven Star Pepper and so on.

Fruit: Warm and cold, strengthen the stomach and eliminate food. It is used for stomach cold pain, flatulence, indigestion;External use for the treatment of chilblains, rheumatic pain, lumbar myalgia.

Root: Promotes blood circulation and reduces swelling. Topical treatment of chilblains[1].

Because there is a lot of capsaicin in chili peppers.