Chemistry of Life

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Chemistry of Life
I. Atoms A. 2 parts (sub-atomic) 1.
nucleus 2. shell (s) cloud (s) B. Periodic
table of elements C. Definitions 1.
elements 2. compounds 3. isotopes 4.
ions II. Molecules A. Molecular bonds B.
Hydrogen bonds III. Origins IV. Water
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Chemical Composition of Human Body
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I. Atoms
A. 2 parts (sub-atomic) 1. nucleus 2. shell (s)
cloud (s)
e-
e-
e-
Inner shell fills first with a maximum of 2
e-
p no
e-
e-
Second shell fills next with a max of 8
e-
e-
e-
p protons
no neutrons
e-
Third shell next with a max of 8 (sort of)
e- electrons
An atoms raison detre is to fill its outer most
shell.
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I. Atoms
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I. Atoms
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I. Atoms
Neutral atom
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Carbon Atom
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B. Periodic table of elements
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C. Definitions

• Elements
• Compounds
• Ions
• Negative ions
• Positive ions

H2O
Emergent property
NaCl
Cl-
Na
H
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C. Definitions

1. Isotopes

Radioactive
Half-life
Carbon 14 dating
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II. Molecules
Linus Pauling
A. Molecular bonds 1. covalent bonds a.
number of bonds and molecular stability b.
polar and nonpolar covalent bonds
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Representing molecules
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II. Molecules
b. Polar and nonpolar covalent bonds
Oxygen is electronegative
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II. Molecules
2. Ionic bonds
Na Cl-
NaCl
oxidized
reduced
(redox)
Oxidation-reduction Rx
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II. Molecules
B. Hydrogen bonds
Dissolve
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Liquid, solid, gas
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II. Molecules
B. Hydrogen bonds
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III. Origins
Big bang!
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IV. Water

• Importance to life
• Properties of water important to life
• High capacity to absorb heat
• Cohesion and adhesion
• Universal solvent
• Solute, solvent, solution
• Hydrophilic, hydrophobic
• Acid/ base chemistry
• Acid
• Base
• pH (- log H )
• Buffers

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1. High capacity to absorb heat
evaporation
Water is a buffer to temperature change
Temperature homeostasis
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2. Cohesion and adhesion
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3. Universal solvent
a. Solute, solvent, solution
b. Hydrophilic, hydrophobic
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B. Acid/ base chemistry
1. Acid 2. Base
3. pH (- log H )
4. Buffers
H gt OH-
Acid
OH- gt H
HOH
H OH-
Base
hydroxyl
Neutral
H OH-
Most common physiological buffer
HCO3-
bicarbonate
pH H buffer pH H


Absorbs H
up
down
high
low
high
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Challenge question treeline
Cascades 7,000 feet
Rocky mountains 10,000 feet
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The end