Transcript Unit 1 (Chapter 4)

Unit 1 – The Chemistry of Life
• Chapter 4 ~
Carbon &
The Molecular
Diversity of Life
Organic chemistry
• Chemistry that contains the
element carbon
–
–
tetravalenc
tetrahedron – 4 covalent
bonds
– shape determines function
Hydrocarbons
• Only carbon & hydrogen
(petroleum; lipid ‘tails’)
• Covalent bonding;
nonpolar
• High energy storage
(fossil fuels)
– Examples include fats,
petroleum, oils, fuel
Isomers
• same molecular formula, but
different structure & properties
• C4H10 shown has two isomers;
butane and isobutane
respectively
• Structural isomers
– # of possible combinations
increases
Geometric
• differing spatial arrangement
due to inflexibility of double
bonds
• Slight difference in shape btw
geometric isomers can
dramatically affect the
biological activities of organic
molecules.
Enantiomers
• mirror images
• Important in pharmacological
industry
• Cells can generally tell the
difference between the two type
– One is useful and the other is
generally not (borderline
harmful in some cases)
– Example: in the 1960’s the
drug thalidomide was
prescribed to pregnant women;
one version of enantiomer was
a sedative, the other caused
birth defects
Three types of
isomers.
• Figure 4.6, page 52
Importance of enantiomers.
• The molecule on the
right is of medical
importance to
Parkinson’s patients,
while the molecule on
the right can cause
birth defects.
Functional Groups, I
• Attachments that
replace one or more of
the hydrogens bonded
to the carbon skeleton
of the hydrocarbon
• Each has a unique
property from one
organic to another
• Hydroxyl Group
H bonded to O;
alcohols;
polar (oxygen);
solubility in water
• Carbonyl Group C
double bond to O;
At end of H C : aldehyde
Otherwise: ketone
Functional Groups, II
• Carboxyl Group
O double bonded to C to hydroxyl;
carboxylic acids;
covalent bond between
O and H;
polar; dissociation, H ion
• Sulfhydral Group
sulfur bonded to H;
thiols
• Phosphate Group
• Amino Group
N to 2 H atoms;
amines;
acts as a base (+1)
phosphate ion;
covalently attached by 1
of its
O to the C
skeleton;