High energy, ultraviolet radiation from the Sun is a known to hazard to life, yet the energy provided by our star has played an important role as the essential driver of life on Earth.
Before life began, radiation from the Sun was the primary source of energy on our planet, just as it is today. In this oxygen-poor, prebiotic world, solar energy may have provided the jolt to transform simple organic molecules into more complex ones, which were used as the building blocks of biology and life.
A new paper by two University of Colorado at Boulder authors considers how this might have happened through a review of existing literature on the topic.
We're looking at examples in the literature and from our own lab where sunlight has been used to build complex molecules from simple, prebiotically-available starting materials,” said lead author Rebecca Rapf, a doctoral candidate in physical chemistry.
The paper, Sunlight as an energetic driver in the synthesis of molecules necessary for life co-authored by her advisor, Veronica Vaida, recently appeared in the journal Physical Chemistry Chemical Physics Rapf's work is supported by a NASA Earth and Space Science Fellowship as well as funds from NASA Habitable Worlds Program.
The lack of oxygen in the early atmosphere means that more high-energy ultraviolet radiation from the Sun would have reached the surface of the prebiotic Earth than today, where it is filtered by ozone. Even though this component of sunlight can be destructive to certain biomolecules, the energy provided could still be useful to early life chemistry, Rapf said. “Even if you destroy a molecule, it is broken into smaller, very reactive chunks that readily undergo additional reactions, recombining to form larger high-energy molecules.
In particular, the researchers were intrigued by a group of oxygen-laden acids called oxoacids. An example is pyruvic acid, which is at the center of key metabolic pathways in life today. When dissolved in water and illuminated with ultraviolet light, pyruvic acid is known to react to make larger molecules, with higher yields under the oxygen-limited conditions that would be found on the early Earth.
Pyruvic acid is only one of a class of molecules that react in the same way to form these larger species. Another molecule in this class, 2-oxooctanoic acid, is particularly interesting because it is an example of a simple lipid. 2-oxooctanoic acid was likely prebiotically relevant, Rapf added, meaning it could be useful to the chemistry that eventually led to life.
See more at: http://www.astrobio.net/origin-and-evolution-of-life/suns-uv-light-helped-spark-life
Related article at: Physical Chemistry Help Online
Before life began, radiation from the Sun was the primary source of energy on our planet, just as it is today. In this oxygen-poor, prebiotic world, solar energy may have provided the jolt to transform simple organic molecules into more complex ones, which were used as the building blocks of biology and life.
A new paper by two University of Colorado at Boulder authors considers how this might have happened through a review of existing literature on the topic.
We're looking at examples in the literature and from our own lab where sunlight has been used to build complex molecules from simple, prebiotically-available starting materials,” said lead author Rebecca Rapf, a doctoral candidate in physical chemistry.
The paper, Sunlight as an energetic driver in the synthesis of molecules necessary for life co-authored by her advisor, Veronica Vaida, recently appeared in the journal Physical Chemistry Chemical Physics Rapf's work is supported by a NASA Earth and Space Science Fellowship as well as funds from NASA Habitable Worlds Program.
The lack of oxygen in the early atmosphere means that more high-energy ultraviolet radiation from the Sun would have reached the surface of the prebiotic Earth than today, where it is filtered by ozone. Even though this component of sunlight can be destructive to certain biomolecules, the energy provided could still be useful to early life chemistry, Rapf said. “Even if you destroy a molecule, it is broken into smaller, very reactive chunks that readily undergo additional reactions, recombining to form larger high-energy molecules.
In particular, the researchers were intrigued by a group of oxygen-laden acids called oxoacids. An example is pyruvic acid, which is at the center of key metabolic pathways in life today. When dissolved in water and illuminated with ultraviolet light, pyruvic acid is known to react to make larger molecules, with higher yields under the oxygen-limited conditions that would be found on the early Earth.
Pyruvic acid is only one of a class of molecules that react in the same way to form these larger species. Another molecule in this class, 2-oxooctanoic acid, is particularly interesting because it is an example of a simple lipid. 2-oxooctanoic acid was likely prebiotically relevant, Rapf added, meaning it could be useful to the chemistry that eventually led to life.
See more at: http://www.astrobio.net/origin-and-evolution-of-life/suns-uv-light-helped-spark-life
Related article at: Physical Chemistry Help Online
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