Life Starts Here
What kind of molecules had to develop into life’s building blocks, including amino acids?
Simple organic molecules
What did the electric sparks in the experiment represent?
Lightning
What feature of Miller’s gas mixture do modern geoscientists question?
Whether the primitive atmosphere was as reducing as Miller’s mixture
In the RNA World hypothesis, what kind of molecule arose before DNA and proteins?
An informational polymer similar to RNA
In the volcanic lightning hypothesis, where did lightning create ingredients?
At localized sites within steamy volcanic eruptions
What molecule can form when ribonucleotides are linked together?
RNA
Name any two gases in the mixture used to represent the early atmosphere.
Methane, ammonia, hydrogen, and water vapor
Why does making amino acids not prove that RNA could be made the same way?
Amino acid synthesis does not imply RNA synthesis; conventional RNA assembly from sugar and base is not possible in an aqueous medium.
What RNA building blocks did Powner and colleagues synthesize in 2009?
C and U building blocks (pyrimidine ribonucleotides)
What simple volcanic gas can help amino acids form peptides under moderate conditions?
Carbonyl sulfide
What do fatty acids form that can enclose chemicals and separate them from the environment?
Bubbles called protocells, which provide a boundary.
What did the 2008 analysis of Miller’s stored samples find?
Twenty-two amino acids and five amines.
According to the poster’s fair judgment, what did the experiment prove, and what did it not resolve?
It showed simple molecules can synthesize amino acids, but it did not resolve the origin of life.
What limitation did the poster identify about the precursor molecules?
Two precursor molecules may not have been available at the same time
What did Bennu samples contain, and what did the nitrogen isotopes suggest?
33 amino acids (14 used by organisms) and five DNA/RNA bases; isotope values indicated an extraterrestrial origin.