Chapter 4 Notes

1
Chapter 4 Notes

• Carbon and the Molecular Diversity of Life

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Concept 4.1

• Compounds containing carbon are said to be
  organic compounds.
• Carbon atoms are very versatile.
• - have 4 valence electrons. It will share
  electrons in 4 covalent bonds (tetravalence)

3
Concept 4.2

• Variation in carbon skeletons contribute to the
  diversity of organic molecules.
• - long chains form carbon skeletons
• - often bonded to several hydrogen atoms forming
  a hydrocarbon.

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Concept 4.2
5
Concept 4.2

• Isomers compounds that have the same molecular
  formula, but different structures (with different
  properties).
• - structural differ in the covalent
  arrangements of atoms.
• - geometric same covalent properties, but
  differ in spatial arrangements.
• - enantiomers mirror images

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Concept 4.2
7
Concept 4.3

• Functional groups components of molecules that
  are often involved in chemical reactions.
• - ex. difference between testosterone and
  estrogen.

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Concept 4.3
Estradiol
Testosterone
9
Concept 4.3

• 6 functional groups are commonly found.
• - hydroxyl, carbonyl, carboxyl, amino,
  sulfhydryl, and phosphate.
• - all are hydrophilic and increase the
  solubility of organic compounds in water.

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Concept 4.3

• Hydroxyl group (-OH)
• names usually end with suffix ol
• ex. ethanol
• organic compounds w/ OH are alcohols
• note do not confuse w/ OH-

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Concept 4.3

• Carbonyl group (-CO)
• -carbon double bonded to an oxygen atom.
• - if at the end of the carbon skeleton will be
  an aldehyde (ex. propanol)
• - if in the middle of a carbon skeleton will be
  a ketone (ex. acetone)

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Concept 4.3

• Carboxyl group (-COOH)
• - oxygen is double bonded to a carbon that is
  also bonded to a hydroxyl group
• - compounds are called carboxylic acids (ex.
  acetic acid)
• - has acidic properties w/ the loss of H ions

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Concept 4.3
Carboxyl
STRUCTURE
NAME OF COMPOUND
Carboxylic acids, or organic acids
Has acidic properties because the covalent bond
between oxygen and hydrogen is so polar for
example,
EXAMPLE
FUNCTIONAL PROPERTIES
Acetic acid, which gives vinegar its sour taste
Acetic acid
Acetate ion
Found in cells in the ionized form with a charge
of 1 and called a carboxylate ion (here,
specifically, the acetate ion).
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Concept 4.3

• Amino group (-NH2)
• - a nitrogen atom is bonded to two hydrogen
  atoms and a carbon skeleton
• - compounds are called amines
• - compounds that have both amino and carboxyl
  groups are called amino acids
• - ex. Glycine
• - amino group can act as a base (NH3)

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Concept 4.3
Amino
STRUCTURE
NAME OF COMPOUND
Amines
EXAMPLE
Acts as a base can pick up an H from the
surrounding solution (water, in living organisms).
FUNCTIONAL PROPERTIES
Glycine
Because it also has a carboxyl group, glycine is
both an amine and a carboxylic acid compounds
with both groups are called amino acids.
(ionized)
(nonionized)
Ionized, with a charge of 1, under cellular
conditions.
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Concept 4.3

• Sulfhydryl group (-SH)
• - Sulfur is bonded to a hydrogen and a carbon
  skeleton
• - compounds with SH are called thiols
• - help stabilize the structure of proteins

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Concept 4.3

• Phosphate group (-OPO32-)
• - formed by dissociation of phosphoric acid
  (H3PO4)
• - used in the transfer of energy between organic
  molecules.

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Concept 4.3
Phosphate
NAME OF COMPOUND
STRUCTURE
Organic phosphates
EXAMPLE
FUNCTIONAL PROPERTIES
Contributes negative charge to the molecule of
which it is a part (2 when at the end of a
molecule 1 when located internally in a chain
of phosphates).
Glycerol phosphate
In addition to taking part in many important
chemical reactions in cells, glycerol phosphate
provides the backbone for phospholipids, the most
prevalent molecules in cell membranes.
Has the potential to react with water, releasing
energy.