First confirmed! There is a source of life outside the Earth! Are there really aliens?

Expert of this article: Yang Chao, PhD in Chemistry, University of Chinese Academy of Sciences

Reviewers of this article:

Feng Lei, Associate Researcher, Purple Mountain Observatory, PhD Supervisor

Zhao Lili, PhD, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (Protein)

Traveling in outer space on a spaceship, encountering aliens

Aliens prepare to rule the Earth, sparking a star war

There is a parallel me on another planet, and it is also sending radio waves to the earth.

…

Have you ever thought that these scenes you have seen in movies or fantasized about in your childhood may come true one day?

Everyone’s first reaction might be to stop daydreaming.

However, today the topic of #The first confirmation of the existence of life outside the Earth# became a hot search and attracted attention.

According to Japanese media reports, the Japanese Ministry of Education, Culture, Sports, Science and Technology said that scientists have detected more than 20 amino acids in samples collected by the asteroid probe Hayabusa 2. This is the first evidence of the existence of amino acids outside the earth.

Image source: Weibo screenshot

Um... What are amino acids? Do aliens really exist? Let's go explore the mysteries of aliens.

What are amino acids?

Amino acids are organic compounds that contain an alkaline amino group (-NH2) and an acidic carboxyl group (-COOH). They are the basic units that make up biological macromolecules. There are more than 300 natural amino acids discovered, but only 20 of them are involved in protein synthesis.

The twenty kinds of amino acids contained in the human body can be divided into two categories: one is non-essential amino acids, including twelve kinds of amino acids such as alanine and arginine, which can be synthesized by the human body; the other is essential amino acids, including eight other amino acids such as lysine, which cannot be synthesized by the human body and can only be obtained from food.

What do amino acids do?

In addition to being used to synthesize protein, amino acids in the human body also play a very important role in regulating life activities.

Copyright image, no permission to reprint

1

Phenylalanine: Involved in amino acid metabolism disorders such as bladder and kidney function damage.

2

Arginine: It is an essential amino acid required by the human body and affects the synthesis rate of urea.

3

Methionine: It plays an important role in the formation of serum and hemoglobin, and can also promote the functional regulation of multiple organs such as pancreas, lymph and spleen.

4

Lysine: It is the main component of human liver and gallbladder. It not only promotes fat metabolism, but also promotes the development of human brain.

5

Tryptophan: accelerates the synthesis and secretion of gastric juice and pancreatic juice.

6

Threonine: can balance multiple amino acids.

7

Valine: acts on the ovaries, breasts and corpus luteum, playing a regulatory role.

8

Isoleucine: Participates in regulating the functions of the spleen, pituitary gland and thymus.

9

Histidine: Participates in negative nitrogen balance and can affect the body's metabolic function.

Since some amino acids have four different tastes: umami, sweet, bitter and sour, monosodium glutamate and glycine can be used as umami seasonings. The main ingredient of MSG, which is commonly used in cooking, is monosodium glutamate.

What does the discovery of amino acids outside Earth mean?

Amino acids are considered to be the building blocks of life because they can be used by organisms to synthesize proteins. Proteins, as biological macromolecules, are also known as the main carriers of life.

Copyright image, no permission to reprint

Amino acids are like letters that can be arranged to form numerous words, and organisms use 20 amino acids to build tens of millions of proteins through a variety of arrangements and combinations.

Amino acids can provide clues to understanding the origin of life. Some scientists believe that life on Earth began after chemical reactions led to the formation of amino acids, which in turn formed proteins, ultimately allowing life on Earth to flourish.

How did the amino acids on the "Ryugu" asteroid form? Some netizens made a bold guess...

What is special about the samples collected by Hayabusa 2 is that they have not been weathered by sunlight or cosmic rays, but are samples collected from underground asteroids. In addition to the isoleucine and valine mentioned above, which cannot be synthesized by the human body, these samples also contain collagen component glycine and umami component glutamate. These amino acids have been confirmed to be highly abundant on Earth after their formation 4.6 billion years ago, but they disappeared after the Earth was covered by magma.

In fact, this is not the first time that scientists have discovered amino acids in the universe. They were detected from meteorites a long time ago, but it cannot be ruled out that these amino acids come from terrestrial pollution.

Is there any life form without amino acids?

From plants to animals, all living organisms contain protein. Even simple life forms, such as viruses, are composed of DNA or RNA plus an outer shell, and the outer shell is composed of protein, so all living organisms contain amino acids.

Copyright image, no permission to reprint

However, there is a kind of "virus-like" (non-living organism), also known as infectious RNA, which is an infectious particle with similar properties to viruses. Viroids are only naked circular closed rod-shaped RNA molecules that can infect higher plants, use enzymes in the host cells of higher plants to replicate themselves, and can cause the death of plants.

As for whether extraterrestrial life contains amino acids, there is no answer yet. Feel free to leave a comment and discuss!

The cover of this article and the pictures with watermarks in the text are from the copyright library and are not authorized for reproduction