Recreating the Miller/Urey Experiment
Amino acids are the
building blocks of proteins, which are the building block of life. In some of
the origin of life theories, the amino acids are thought to have come from the
chemicals and gases present on the primitive earth, if there was a primitive
earth. Evidence have suggested that the gases and compounds Miller and Urey used
in their famous experiment were not the real ones that existed on the so-called
primitive earth. The purpose of this experiment is to see what will be produced
from the latest ideas of what existed on “primitive earth” and compare it
with the Miller/Urey experiment. Therefore, the question would be what will be
produced from the mixture of chemicals in the “real primitive earth” and
some energy source, if there was ever a primitive earth. The implications of
this experiment may be that life did not come from non-living matter present on
earth.
Miller and Urey used gases
present in the atmosphere of primitive earth, but the gases they used are no
longer thought to be present. I will recreate the Miller/Urey experiment as the
control and compare the results with the mixture of the latest ideas of what was
probably on primitive earth to see if amino acids were produced and if its
sufficient for proteins. My hypothesis is that the new experiment with the new
gases will not produce the building blocks necessary for life. Even if there
were amino acids, there is a huge difference between amino acids building blocks
and the assembled protein. There is a 10130 combination of 20 amino
acids (if 20 can be produced spontaneously) to form one protein.
To recreate the Urey/Miller
experiment, I will mix methane (CH4), hydrogen (H2),
ammonia (NH3), and water vapor (H2O) in a flask just like
what they did. They excluded oxygen because oxygen is believed to be from
photosynthesis and were not present on the primitive earth’s atmosphere. The
setup is shown in the picture, with two tubes connecting to another flask, which
is connected a power supply, simulating energy in the form of electricity
(lightning). This process is supposed to happen in the earth’s atmosphere. The
flask with all the compounds will be heated to boiling temperature because of
the heat present on primitive earth. Because of the heat, the liquid solution
will evaporate into clouds. The lightning will then strike the clouds, which
would then condense and form into liquid again (the primordial soup raining onto
earth). The process will go on for a week, as Miller and Urey did. The result
will be what has become of the solution. (In the Miller/Urey experiment, amino
acids and other complex organic molecules were produced in a week)
There were several problems with the Miller/Urey experiment. First scientists
now believe methane and ammonia were not present in the primitive earth’s
atmosphere. Hydrogen would also have escaped because of its lightness. The best
guess is that earth’s primitive atmosphere contained nitrogen (N2),
Carbon dioxide (CO2), water vapor (H2O), and maybe some
carbon monoxide (CO). Miller and Urey also used all reducing gases, opposite of
oxidizing. It is now believed that the atmosphere was neutral, neither reducing
nor oxidizing. The above-mentioned gases are neutral. I will do the same with
these gases and compounds. They will be placed in a boiling flask with tubes
connecting it to the energy source, as shown in the picture. There will be two
experiments going on at the same time for one week. After one week, the solution
will be thoroughly examined to see what has become of them. They will be
compared and a conclusion will be made.
