Biology Questions and Answers
ultraviolet radiation. The temperatures
in the atmosphsurface were very high. Electricity,ere and on the planet
radiation and heat constituted large
available energy sources.
- What was the experiment
of Stanley Miller (1953) on the
origin of life?
In 1953 Stanley Miller arranged an
experimental athe atmospheric conpparatus that simulatedditions of the
primitivecontained earth. a mixture The experimentof methane, (^)
ammonia, hydrogen and circulating
water that when heated wastransformed into vapor. He submitted (^)
the mixture to continuous bombardment
of electricalobtained a liquid residual within w discharge and after dayshich (^)
he discovered organic molecules and
among them surprisinacids glycine and alanigly the aminone, the most
abundant constituents of proteins. Other
researchexperiment aers reproduced the Millernd noted also the
formation of other organic molecules
such as lipids, carbnucleotides. ohydrates and
- What are coacervates?
Coarcervates are small structures made
of the aggregation ounder water solution. f organic moleculesBy electrical
attraction the molecules join into bigger
and more organized particles distinctfrom the fluid environment forming a (^)
membrane-like structure that separates
an interfrom the exterior. Tnal region of the coacervatehe coacervates
might divide themselves and also
absorb abelieved that these structures may havnd excrete substances. It is (^) e
been the precursors of cells.
- How can coacervates be
formed of phospholipids or
polypeptides?
Phospholimolecules, i.pids are e., they amphipathicpresent a (^) polar
portion contact with water and a nonpolar pothese moleculrtion. Ines tend (^)
to spontanthemselves feously uorming memnite and organizebranes that (^)
create a closed interior space separated
from thPolypeptide chains ie exterior environment.n their turn (^) can
attract water (by electrical attraction)
forming a surralso creating an organized structureounding water layer and
with delimited interior space.
- How could coacervates
have facilitated the
emergence of life on earth?
Coacervatesseparation b probably provided a nitidetween an internal and an (^)
external eorganic material within nvironment and thus thwas not lost toe (^)
the ocean. The enzymaticthat internal environment could develop action inside (^)
in different manners increasing the
speed of specific chemicalCoacervates also allowed the molec reactions.ular (^)
flux across its membrane to be
selective.molecules a Since cond differently organizedntaining different (^)
from each other, coacervates could
have promoted a competition for
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