The submarine hydrothermal vent spewed boiling water into the cold ocean above. Within one meter, the temperature varies from hot to cold. Most importantly, there is a lot of pressure and no light. This unimaginable environment is home to the "Snowman Crab", a clawed crustacean first discovered in 2005. Their furry forelimbs look like snowmen. Since the first discovery, only five species of Sherman crabs have been discovered. But they are all over the southern hemisphere. These strange little creatures have found a way to survive in the most extreme environment in the world.

Aside from the name, Sherman crabs are not real crabs, they all belong to crustacea. Snowman crabs live around small cracks in submarine basalt sprayed with hydrothermal solution and at the bottom of some smoking submarine craters. Although the environment is extremely harsh and has great pressure peculiar to the deep sea, the water around the hydrothermal vent is still "mild 32℃" compared with the common 2℃ on the seabed. In other words, they may never enter the hydrothermal solution at 400℃, because scientists have not seen them in submarine cracks and craters where hydrothermal solution is sprayed. They are mobile, so they can escape from very hot water if they want.

Scientists also noticed that the Sherman crab showed a strange behavior. They seem to put their furry forelimbs on the hot water flowing from hydrothermal vents. After careful observation, the researchers found that the hair of the forelimbs was covered with thousands of bacteria. Some people think that Sherman crab may be "cultivating" bacteria as a food source.

The second kind of snowman crab lives on the bottom of the sea near Costa Rica. It is similar to the habitat of hydrothermal vents that release methane and hydrogen sulfide gas. Unlike hydrothermal vents, the water released from the leak is not hot, but the temperature is the same as that of the surrounding ocean. Scientists began to believe that they were cultivating microorganisms.

In order to prove that bacteria rather than plankton are the main food source of Sherman crab, scientists analyzed its carbon and fatty acids. They are very similar to those found in bacteria. In addition, carbon exists in a specific form and only exists in organisms that can obtain energy without using sunlight. In other words, carbon cannot come from photosynthetic plankton. It must come from bacteria, which use the process of chemical synthesis to get energy from the oozing gas.

Snowman crabs don't just sit there and passively let bacteria grow on them. They wave their forelimbs in the water and actively cultivate microorganisms. This movement provides a stable flow of oxygen and sulfide gas for bacteria, which may help them grow. The forelimbs of Sherman crab swing back and forth in the liquid oozing from the seabed, and bacteria are cultivated on the forelimbs and body. "They swing back and forth rhythmically to ensure that the microorganisms on them can grow as fast as possible. Sometimes they scrape these bacteria off their bodies and forelimbs with their mouths. Although the environment under the sea is not friendly to us, the Sherman crab is very relaxed.

The snowman crab can't see anything, so darkness is not important. As for heat, salinity and water pressure, these are their habits and adaptations. The temperature in that area has remained constant for thousands of years, and they live in one of the most stable environments on earth. 20 10 The hairy chest and muscular appearance of the third kind of Sherman crab are reminiscent of the British actor David Hasselhoff, so Sherman crab is nicknamed Hoff Crab. Hof crabs crowded around the submarine hydrothermal area and waved their forelimbs back and forth to get as many sulfides as possible. They even seem to drive away blind shrimps: these smaller crustaceans may also want to touch this liquid.

This is the most tenacious and tenacious snowman crab found so far, because the conditions it has to deal with are so extreme. This is because, although the ejected volcanic water may be as high as 400℃, the water temperature is almost 0℃ only a few feet away from the spout. Hof crab may be the only animal that lives in extremely hot and cold environment. Despite the harsh conditions, the crater is still full of snowmen and crabs. Sherman crab can't survive in hot water at 400℃, and can be cooked by ordinary cooking methods.

Deep-sea volcanoes and hydrothermal vents are formed at the intersection of seawater and magma, and minerals contained in hydrothermal fluids form chimney-like structures when cooled.

There are some small creatures living near the black chimney, such as blind shrimp, blind crab, etc., and there is also a famous snail called scaly-horned gastropod snail, which is covered with a hard shell of iron sulfide.

They all live in hot water at 400 degrees.

So can they be cooked or not? The answer is that the question of being able to cook has something to do with the protein structure that constitutes the organism.

All living things in the world are evolved from single-celled eukaryotes. The cell structure of blind crab and shrimp is similar to that of birds, reptiles and mammals, and so is protein.

An egg is a big piece of protein. Why are eggs semi-liquid when they are raw and solidified when they are cooked?

Has the egg changed chemically or physically?

Protein's molecules are long chains of amino acids. Because it is long, it will fold and bend. Protein after folding and bending is called the spatial conformation of protein, and this folding will be repeated many times to form secondary, tertiary and quaternary folds.

Protein has all the functions of protein after folding.

The reason why the folded protein can keep a stable shape is that there is an intermolecular force called hydrogen bond that locks these folds.

Hydrogen bonds provide most of the directional interactions of protein folding, protein structure and molecular recognition. The core of most protein structures consists of secondary structures such as α-folding and β-folding. This satisfies the hydrogen bond potential between carbonyl oxygen and amide nitrogen in the main chain of protein hydrophobic core.

The hydrogen bond between protein and its ligand (protein, nucleic acid, substrate, effector or inhibitor) provides the directionality and specificity of the interaction.

As we know, an atom is composed of a nucleus and an electron cloud orbiting the nucleus. It is spherically symmetric and does not show positive and negative polarities when no molecules are formed.

However, after the formation of molecules, due to the need to enjoy electron pairs, the shape of electron clouds has been deflected, and atoms will show electronegativity or electronegativity in a certain part.

This kind of positive and negative electricity will attract each other, and the most common one is the so-called hydrogen bond formed by the mutual attraction of hydrogen atoms and other atoms.

In the spatial conformation of protein, hydrogen bonds provide 70% structural locking, and the other 30% is provided by disulfide bonds.

Protein molecules form a spatial conformation, just like a ball of wool rolled into a ball. There is no boiled egg, and the protein inside is like this, so it has a certain fluidity.

Cooked eggs, the hydrogen bond that locks the protein structure is broken, and protein molecules expand into long chains and intertwine with each other, thus becoming solid.

Like a ball of wool that can roll around on the ground. It's difficult to roll up after knitting into a sweater.

So the condition of life is that the hydrogen bond in protein will not be destroyed.

Blind crabs and blind shrimps can survive in 400-degree seawater because the hydrogen bond that locks the spatial structure of protein has not been destroyed.

The strength of hydrogen bond is related to other atoms in the para position of hydrogen atom. The strongest hydrogen bond is H~F bond, followed by H~O bond and H~S bond. The more oxygen atoms there are, the greater the possibility of hydrogen bonding.

Hydrogen bond is a weak bond, and its strength is between weak van der Waals force and strong valence bond. The dissociation energy depends on polar attraction, so it depends on the electronegativity of atoms.

In addition, pressure also has a great influence on hydrogen bonding.

The higher the pressure, the stronger the hydrogen bond and the higher the dissociation energy, because the spacing between molecules is smaller.

The reason why water can remain liquid at normal temperature and pressure is that hydrogen bonds lock water molecules. At one atmospheric pressure, the boiling point of water will reach 100 degrees, but with the increase of pressure, the boiling point of water will rise. Because the bonding energy of hydrogen bonds will increase with the increase of pressure, it takes higher temperature to destroy the stability of hydrogen bonds.

At this point, we can answer the first question. The hydrogen bonds of blind crabs and blind shrimps living in 400℃ water will not be destroyed under high pressure, but at normal atmospheric pressure, 100℃ can destroy their hydrogen bonds.

Therefore, blind crabs and shrimps living in 400-degree hot water in the deep sea can be cooked with flour, fried and steamed with chopped green onion.

Crabs near deep-sea volcanoes can tolerate high temperatures of 400℃. How to cook and eat them?

70.8% of the earth where we live is covered by oceans. However, our exploration of the depths of the ocean is far from enough, mainly because of our scientific and technological level. At present, it is far from being able to adapt to the cruel environment of no sunshine, ultra-high pressure and low oxygen content on the seabed (especially in the deep sea). Many instruments and equipment have been "killed" before falling to the bottom of the sea, not to mention that we humans have experienced it personally, only a few researchers and explorers.

As far as we know, the underwater world is not completely barren, but there are also some micro-ecosystems composed of extremely vital organisms, and the important factor supporting these ecosystems is that there are certain sources of material and energy input. There are three typical types of "input", namely deep-sea hydrothermal solution, cold spring and whale landing. These three forms are vividly called "three life oases in the deep sea", for example, near-deep sea hydrothermal solution. There are also some invertebrates such as sea crabs. As far as we know, the temperature of deep-sea hydrothermal solution can reach 400 degrees Celsius. Some people can't help asking, since crabs here can tolerate such high temperatures, can we cook them when we catch them?

This is a very interesting question. First, let's take a look at what is deep-sea hydrothermal solution. Deep in the seabed crust, there are many heated high-temperature hot water filled in the cracks in the rock stratum. Because of the high temperature, the minerals in the surrounding rocks have great solubility in hot water, which is sometimes ejected from the weak parts of the seabed crust under the influence of crustal pressure release. When it comes into contact with the cold seawater at the bottom of the sea, the minerals originally dissolved in hot water will immediately precipitate and pile up into a "chimney" shape at the nozzle. Due to the different minerals, the stacked "chimneys" have different colors, including white, yellow and black.

Because the ejected hydrothermal solution still contains a certain amount of minerals, hydrogen sulfide and other gases, and the intersection with the cold seawater can make the surrounding seawater extremely warm, some bacteria and microorganisms will gather near the hydrothermal vent, which feed on minerals and hydrogen sulfide, then synthesize organic matter and attract invertebrates such as crabs, oysters and mussels. After all, it is warm here and there are many food sources. It is really a "hole in the sky".

I think there are two main reasons why these invertebrates are not scalded or cooked by hydrothermal solution: first, these animals are not purely active in hydrothermal solution, but in the area where hydrothermal solution and cold seawater meet and mix. Although the gushing of hydrothermal solution is usually continuous, compared with the surrounding vast and huge cold seawater, its water output is quite different, so its influence on the heating of surrounding seawater is very small, only in a relatively small area near the nozzle, while the active area of sea crabs is basically in the area where hydrothermal solution meets cold seawater or further away, and the temperature in this area is much lower than 400 degrees Celsius, even less than 100 degrees Celsius.

The second is the influence of deep-sea pressure. Protein in animals is an important basic substance that determines biological activity. It is a complex structure composed of long-chain amino acids. From the perspective of spatial conformation, protein can have corresponding physiological functions and show biological activity only after N folds, and the hydrogen bond between amino acids provides a stable "structural locking" guarantee for protein's folding. If the hydrogen bond between amino acid molecules is broken, protein molecules will unfold, thus losing their physiological functions and activities. For example, if we boil eggs with water, the amino acid molecules in the eggs will be destroyed due to high temperature, and the long chain of protein will unfold and stop folding, thus losing its activity. In the deep sea, the pressure on the seabed can reach hundreds of thousands of standard atmospheres, and the hydrogen bond force between protein will increase with the increase of pressure, so the temperature required to break the hydrogen bond between amino acid molecules will increase a lot. Therefore, even crabs at the bottom of the sea will not be harmed in a certain period of time if they break into hydrothermal solution.

Therefore, crabs at the bottom of the sea can survive near the hydrothermal solution of 400 degrees Celsius, which is not only related to their range of activities, but also closely related to the strong bonding force of hydrogen bonds under the strong water pressure in the deep sea. If you are lucky enough to catch deep-sea crabs, heating the water to 100 degrees Celsius at normal atmospheric pressure will also destroy the hydrogen bonds in its amino acid molecules, and protein will soon lose its activity and be easy to cook.