Biomolecules

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BB10A Cells, Biomolecules Genetics 2003-04
Semester 1

• Tuesday 30 Sept.
• Lecture 3
• Biomolecules their interactions with Water
• Andrew Pearson

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Biomolecules their interactions with Water
Life on our planet has evolved to cope
with a predominantly aqueous
environment roughly 70 of the Earths
surface animal bodies are H2O
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Biomolecules their interactions with Water
The properties of H2O have therefore had a
powerful effect upon the forces of natural
selection at the level of the
Biomolecule.
Let us look at some properties of H2O.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
In contrast to hydrophobic substances, many
biochemically important ions and molecules are so
hydrophilic that Osmotic pressure results.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
Another important property of H2O is its
ability to dissociate into both a weak acid and a
weak base.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
The effect of water upon natural selection is
quite marked even at the molecular level the
case of the most abundant biosynthesised
molecule, Glucose.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
Proteoglycan aggregate
Hyaluronic Acid core
Chondroitin sulphate
Keratan sulphate
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Biomolecules their interactions with Water
The less it is allowed to interact with aqueous
media, the stronger a H-bond can be. This is
important in the stability of macromolecules such
as DNA
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
All things naturally prefer (are more stable in)
the lowest possible energy state. For H2O in the
biosphere (i.e. between 0oC and 100oC) this means
random motion, not an ordered structure.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
This effect is important in the stabilisation of
biomembranes
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Relative abundances of elements in the universe
Biomolecules their interactions with Water
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Relative abundances of elements in Earths crust
Biomolecules their interactions with Water
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Relative abundances of elements in humans
Biomolecules their interactions with Water
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Biomolecules their interactions with Water
Human body
Universal
Earths crust
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Biomolecules their interactions with Water
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Apart from photosynthesising organisms, which
take energy from e/m radiation, all the
biochemical needs of the biosphere for life come
from chemical elements, salts and
molecules found in the lower regions of the
atmosphere, the hydrosphere and the upper parts
of the lithosphere.
Biomolecules their interactions with Water
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Biomolecules their interactions with Water
Ecology studies are often enhanced by
under- standing how and why elements cycle
through different systems in the biosphere,
recent perturbations of ecological balances by
human activities have brought these matters into
sharp focus.
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water
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Biomolecules their interactions with Water