Water's Structure & its Role in the Origin of Organic Molecules
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ICE: at temps below freezing (0◦) water molecules assume their
most STABLE
configuration, organizing neatly and strengthening its H-bonds over hundreds
of water molecules (fig). Crystalline
water's (ice's) shape is HEXAGONAL,
with every oxygen atom forming a 6-fold pattern as we see in snowflakes.
LIQUID WATER: H-bonds redistribute rapidly & constantly (CUBIC), thus the structure
of water adjusts to its local environment, i.e., an
air bubble can rise through liquid
water, but not through structure solid ice. Organic molecules can travel between
liquid water molecules and recombine into more complex organics, characteristic
of living things. Solid hexagonally structured ice expels organic compounds from
its crystal structure preventing their forming more complex polymers.
AMORPHOUS ICE: at temps close to absolute zero (10 to 65◦K) the oxygen atoms can
stack up in CUBIC H-bond patterns forming
amorphous ice. Without a structured
or specific order UV light/radiation (energy) causes this ice to "flow" like liquid
water and thus organic molecules
[CH3-OH & NH4] can form within from
inorganics
such as CO, CO2. At
temps from 65 to 125◦K
amorphous ice becomes less dense
and H-bonds break and reform allowing the recombination of organics
(albeit much slower than in liquid water - 100,000 years vs. 1 second).