The chemical origin of life on Earth is a puzzle that scientists have been trying to piece together for decades. Many hypotheses have been proposed to explain how life came […]
RNA
![Chiral molecules can spin polarize magnetic surfaces due to the CISS effect. A. Electron density of a molecule approaching a surface is asymmetrically distributed and a transient charge dipole is created. Charge transport through chiral molecules is spin selective due to the CISS effect and therefore a spin-dipole along the chiral molecular axis accompanies this charge dipole. This transient spin dipole can couple with surface spins due to the spin-exchange interaction (J ≡ [E(↑↑) − E(↑↓)]) and spin polarize the surface along the chiral molecular axis. B. Schematic of the setup used in crystallization experiments for CD detection. Homochiral crystals of RAO are formed on magnetite from their enantiopure solution. These crystals align the magnetic domains under them and interact with the surface spins due to magnetic dipolar coupling—a weaker but longer range coupling compared to the spin-exchange interaction C. A sequence showing the effect of chiral molecules on the magnetic domains. 1 Initially, there is no net magnetization of the magnetic domains. 2 As a layer of RAO is forming, the spins underneath the layer align due to the strong spin-exchange interaction. This is an avalanche magnetization process: molecules align the surface spins and the aligned regions attract more molecules and get larger. 3 The mono-layer grows and covers more surface due to the attraction of chiral molecules to the aligned regions and crystal seeds start forming. 4 Crystals get larger and couple with the magnetic domains due to magnetic dipole-dipole interaction, Edd. D. If an external magnetic field, −→B, is applied, the domains outside the area covered by crystals magnetize. Yet the crystals preserve the magnetization of the domains under them as long as the energy of the dipolar coupling is larger than the magnetic energy. -- physics.chem-ph](https://i0.wp.com/astrobiology.com/wp-content/uploads/2023/06/Chirality.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry, Biochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release
Chirality-Induced Magnetization of Magnetite by an RNA Precursor
Life is homochiral and homochirality is a fundamental feature of living systems on Earth. While the exact mechanism that led to homochirality is still not fully understood, any realistic scenario […]
Posted inBiochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
Origin of Biological Homochirality by Crystallization of an RNA Precursor on a Magnetic Surface
Homochirality is a signature of life on Earth yet its origins remain an unsolved puzzle. Achieving homochirality is essential for a high-yielding prebiotic network capable of producing functional polymers like […]
Posted inBiochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
The Central Dogma Of Biological Homochirality: How Does Chiral Information Propagate In A Prebiotic Network?
Biological systems are homochiral, raising the question of how a racemic mixture of prebiotically synthesized biomolecules could attain a homochiral state at the network level.
Posted inGenomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
The RNA-DNA World And The Emergence Of DNA-encoded Heritable Traits
The RNA world hypothesis confers a central role to RNA molecules in information encoding and catalysis.
Posted inGenomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
How To Build A Protoribosome
NASA-supported scientists have reexamined some previous assumptions about how the ribosome in living cells is constructed. The ribosome is a large molecule found in all living cells that catalyzes the […]
Posted inBiochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release
A Prebiotic Genetic Alphabet As An Early Darwinian Ancestor For Pre-RNA Evolution
RNA-based genetic code is thought to be central to life’s emergence due to its dual ability for information transfer and catalysis. Nonetheless, the genetic code of early life was potentially […]
Posted inAstrochemistry, Biochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Missions & Hardware, Press Release
Uracil Has Been Found In Asteroid Ryugu Samples
Researchers have analyzed samples of asteroid Ryugu collected by the Japanese Space Agency’s Hayabusa2 spacecraft and found uracil—one of the informational units that make up RNA, the molecules that contain […]
Posted inBiochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release
Solving The Mystery Of Left-handed Amino Acids In Primordial RNA Reactions
While humans have an esthetic liking for symmetry in everything, nature prefers asymmetric, single-handed forms when it comes to amino acids—the building blocks of proteins, and, by extension, all things […]
Posted inBiochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report
RNA Folding Studies Inside Peptide-rich Droplets Reveal Roles Of Modified Nucleosides At The Origin Of Life
Compartmentalization of RNA in biopolymer-rich membraneless organelles is now understood to be pervasive and critical for the function of extant biology and has been proposed as a prebiotically-plausible way to […]