Japan Geoscience Union Meeting 2023

Presentation information

[J] Online Poster

U (Union ) » Union

[U-08] Biogeochemistry of CO world

Mon. May 22, 2023 10:45 AM - 12:15 PM Online Poster Zoom Room (1) (Online Poster)

convener:Yuichiro Ueno(Department of Earth and Planetary Sciences, Tokyo Institute of Technology), Norio Kitadai(Japan Agency for Marine-Earth Science and Technology), Shino Suzuki(Japan Aerospace Exploration Agency), Kazumi Ozaki(Tokyo Institute of Technology)

On-site poster schedule(2023/5/21 17:15-18:45)

10:45 AM - 12:15 PM

[U08-P09] Origin of DNA and origin of genetic code

*Shinji Karasawa1 (1.Miyagi National College of Technology Professor emeritus)

Keywords:Spiral structure, Chirality, t-RNA , m-RNA , DNA , Codon

There is a hydrothermal vent model as the origin of life, but hydrothermal vents are local areas, and organisms born there cannot diffuse and live in areas with different environments. Almost all living creature on Earth are made up of proteins whose chirality is composed of D-type sugars and L-type amino acids. Until now, molecular biology of the gene has not recognized that chirality plays very important role in the process of protein synthesis.
The amino acids extracted from the Murchison meteorite contained almost equal amounts of left and right types. This is evidence that life on Earth had not come from space.
If amino acids are directly related to messenger RNA (which indicates the sequence of amino acids) , amino acids bind selfishly to messenger RNA and accurate replication is not possible. Therefore, the relationship between t-RNA, (which carries amino acid) and m-RNA is checked by the genetic code that is not related to amino acids, and the amino acid sequence is determined through t-RNA only when the matching conditions are satisfied.
Two helixes in a DNA are face to face. But the progress of D-type of t-RNA is opposite to that of L-type of m-RNA. So, each step of m-RNA sequence compared with t-RNA that is connected individual amino acid. The matching is performed with a codon of the genetic code, and the protein is replicated by connected t-RNA by m-RNA.
The water is a structure of one huge molecule whose three-dimensional structure frequently changes due to he hydrogen bonding, creating a structure in which water molecules are spirally arranged under a planar water surface.
Current organism cell membranes are commonly C16 H34 or C18H38 It has a structure located perpendicular to the surface of the water. The hydrophobic long-chain molecules that became the cell membrane of the organism are C16H34 with a melting point of 20 C and a boiling point of 300 C, and C18 H38 had a melting point of 27.8 C and a boiling point of 316.15 C. Those were suspended as an oil film on the water surface of the primitive Earth. Many of the hydrocarbon molecules synthesized in the atmosphere of CO2, collided with H+ in the solar wind and remained in the sky because of their low boiling point. Many of the hydrocarbon molecules synthesized in the sky when CO2, the main component of the atmosphere at the time, collided with H+ in the solar wind and remained in the sky because of their low boiling point, and H+ in the solar wind A synthesis reaction was carried out in response to the exposure of.
The spiral structure of water has penetrating vacant channels, and oil molecules penetrate perpendicular to the water surface. Since long-chain hydrocarbon molecules with oxygen attached to the tail do not penetrate the surface of the water, cell membranes were formed by hydrophobic interactions outside the hydrophilic part.
On the other hand, carbohydrates (Cx (H2O) y) can be produced on the surface of hydrocarbons floating on the surface of water, so macromolecules consisting of monosaccharides bound by glucosides bonds. So, long-chain polymeric carbohydrates consisting of monosaccharide units are added to the area neighboring the L-typed amino acids that invade when making proteins. The nucleic acids of spiral-shaped sugar molecules adhered individual amino acid become the D-type transport RNA (t-RNA) The amino acid sequence of a protein composed of many amino acids produces L-type messenger RNA (m-RNA) that connects many D-type t-RNAs by using the genetic code (codon) of DNA. Since m-RNA has a short lifespan, the helical sugar of D typed m-RNA forms DNA in stable molecular regions by dehydration binding. When the double spiral structure is twisted, the L-type molecular row is brought closer to the D-type molecular row depending on the direction of rotation. The relationship between the keys and locks of the two bases can be separated or brought closer.
The DNA genetic codes is used to match m-RNA to t-RNA. The amino acid sequence of the protein is set through t-RNA with matching amino acids of m-RNA. If there is a physical relationship between the genetic code of DNA and amino acids, the correct sequence of protein synthesis is impossible. The mechanism is unrelated to the genetic code of DNA and amino acids.
[Reference] S. Karasawa, Origin of life in the water of the Earth, The journal of Geology, Earth & Marine Science, Volume 5(1) : 1-7 , 2023