Chemistry 25 May 2010
Transcript of Chemistry 25 May 2010
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Basics of Chemistry
Its all about the electrons!
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Topics to be covered
Atomic structure
Chemical bonds
Binding to metals & non-metals
Potencyvs
. bioavailability
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Atomic structure
The electron orbit around the nucleus is
similar to that of moons around a planet, except
a) The force holding the electrons in place is
electromagnetic, not gravitational
b) Not all the orbits are circular.
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Molecular structure
The electrons in atoms can form bondsbetween the nuclei, forming molecules.
It takes two electrons to form one bond.
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Sharing or hoarding electrons?
In a non-polar covalent bond the
electrons hold the atoms together
similar to using rubber bands.
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Sharing or hoarding electrons?
Ionic
In an ionic bond the attraction between electron
rich (-ve) and electron deficient (+ve) is similar to
the north and south poles of two magnets.
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Sharing or hoarding electrons?
Ionic
There is a wide range of
polarized binding lying
between the extremes of
non-polar covalent and ionic.
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Binding to metals and non-metals Metals often have a positive charge and
want to receive electrons.
Non-metals often have a negative chargeand want to give electrons.
Opposites attract.
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Binding to metals and non-metals
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Metal Acid
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Binding to metals and non-metals Acids are non-metals; they will bind to
metals to form the metal salts.
Aspartic acid binds to zinc to form zinc aspartate.
Citric acid binds to calcium to form calcium
citrate.
Selenium and phosphorus are not metals;acids will not bind to Se or P.
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Binding in amino acid chelates
The nitrogen in the amine group shares two of
its electrons with the metal atom.
The oxygen in the carboxyl group gives one
electron to the metal. The metal gives one
back and they share the two.
These two bonds between the amino acid and
the metal give the chelate its stability.
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Potencyvs
. bioavailability Potency is simply the amount of nutrient
present. This is a chemical measurement.
Bioavailability is a measure of the uptake by
the body. This is a biological measurement.
Copper sulfate (25% Cu) has a greater potency
than Copper AAC (15% Cu) but the Cu AAC hasa higher bioavailability. Why is this?
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Summary
Chemical binding is determined by the electron
configuration.
Opposites attract.
The more bonds, the more stable the molecule.
Hence the chelate effect.
Next month product quality; reacted and non-
reacted products.
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