Chapter 2 The Chemical Context of Life

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Chapter 2The Chemical Context
of Life
Hey psst, did Mr. Slagel teach us the chemical
formula for sand..
Are you kidding. It is still summer, I am still
on the beach (at least in my mind).
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Actually, Chemistry is THE FOUNDATION of all
BIOLOGY
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Atoms

• Smallest particle of elements.

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Element

• Matter made up of only one type of atom.
• 92 natural elements.
• Each element has a symbol.

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Question?
Which Elements are necessary For Life? Life
requires about 25 chemical elements.
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Macroelements

• Elements needed in large amounts or quantities.
• Examples
• C HOPKNS CaFe Mg NaCl

Control
Minus Nitrogen
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• Trace Elements - required by an organism in
  minut quantities.
• ex. Fe, I, Mg

Goiter minus Iodine
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Atomic Particles

• Protons
• charge, 1 Dalton mass
• Neutrons
• no charge, 1 Dalton mass
• Electrons
• - charge, essentially no mass

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• Isotopes- same ps
• differing of neutrons. -
• Uses in biology as tracers

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PET Scan
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• Electron Configuration and Chemical Properties -
• An atoms electron configuration determines its
  chemical behavior

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Energy
The ability to do work.
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Potential Energy
Is the energy that matter stores because of its
position or location. Electrons have potential
energy because of their position relative to the
nucleus.
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Electron Orbitals
The three dimensional space where an electron is
found 90 of the time. Different orbitals have
different shapes. Each orbital can hold only 2
electrons.
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Chemical Bond Types
Nonpolar Covalent Polar Covalent Ionic Hydrogen Va
n der Waals
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Atoms combine by chemical bonding to form
molecules - Ionic Bond - (weak in the presence of
water) Hydrogen Bond- (weak) bonds between
molecules.
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A molecules shape determines function. Is this
an emergent property?
Shape is important b/c it determines how
molecules respond to one another complementary
shaped molecules are able to bind to each other!
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