1) Properties of Water
Water is a polar
covalent solvent
•Oxygen end is slightly negative
•Hydrogen ends are slightly positive
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Hydrogen Bonding
• Polarity of water
allows attraction
between other water
molecules
– Hydrogen bond - attraction
between hydrogen and another
highly electronegative atom
(FON)
– Weaker than covalent or ionic
bonds
– Water is unique in that one
molecule can form up to 4
hydrogen bonds.
Properties of Water
Cohesion: attraction between 2 molecules of
same substance
Adhesion: attraction between 2 different
molecules
-Capillary action - forces between molecules cause
water levels to rise against gravity (One way plants draw
water from their roots).
Solutions and Suspensions
• Solution: Type of
mixture with
components evenly
distributed.
– Solute: What is dissolved.
– Solvent: Substance which
solute is dissolved in (usually
water).
– Like dissolves like!
Suspension: Mixture in
which material will not
dissolve
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Acids, Bases, and pH
• Water can ionize:
H2O  H+ + OH-
• pH Scales measures the concentration of Hydrogen and Hydroxide
ions in solution.
– Ranges from 0 to 14
– pH of 7 is neutral (H+ = OH-)
– pH less than 7 is considered acidic (H+ > OH-)
– pH greater than 7 is called basic (H+ < OH-)
– Each value on the pH scale is a a factor of 10!
» pH of 3 vs. pH of 5, the pH of 3 has 100 times more hydrogen ions!
pH Scale
Acids and Bases
• Acids are compounds that produce H+
ions in solutions.
• Bases are compounds that produce OH- in
solution.
• *Buffers are weak acids or bases that can
react with strong acids/bases to prevent
sharp changes in pH.
2) Organic Compounds
• Organic Chemistry refers to the study of
carbon compounds.
– 1) Carbon atoms have 4 valence electrons,
and can form 4 individual covalent bonds.
– 2) Carbon can bond with itself (single,
double or triple covalently), creating the
possibility of huge chains.
– Polymerization - the formation of large
molecules from smaller components.
4 Major Organic Components
of Life
• 1) Carbohydrates:
– Contain C, H, O in a ratio of
1:2:1.
– Main source of energy.
– Short and long term storage
– Name ends in -ose
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1) Carbohydrates
– Monosaccharides: single molecule sugars
• Glucose, Fructose, Galactose
• Chemical Formula C6H12O6
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– Disaccharides: double sugars
• Maltose, Sucrose, Lactose
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How do macromolecules
form?
• Dehydration synthesis!
– Through a reaction of two molecules and energy,
water is produced.
– The reverse is known
as Hydolysis
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Carbohydrates
• Polysaccharides: 3 or more simple sugars
bonded together.
– A) Starch main form of energy storage for plants.
– B) Glycogen (Animal starch) form of storage in
animals.
– C) Cellulose chains of glucose formed in plants for
support structures.
– D) Chitin is a polysaccharide that makes up
exoskeletons of many insects.
2) Lipids - oils, fats, waxes
• Contain C, H, O (H:O ratio is greater
than 2:1 so lots of Hydrogen!)
• Used for long term energy storage (fat
tissue)
• Make up cell membranes
Lipids
• Lipids are usually
formed through the
dehydration
synthesis of a
glycerol molecule
and 3 chains of
fatty acids.
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Lipids
• Saturated is a term that
refers to a lipid containing
only single covalent
bonds between carbon
atoms in the fatty acid
tails
• Unsaturated means that
there are one or more
double bonds between
carbons in the tails of the
lipid.
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3) Nucleic Acids
• The molecules of heredity!
• Contain Hydrogen,
Oxygen, Nitrogen, Carbon
and Phosphorus.
• Individual monomers are
known as nucleotides.
• Nucleotides have 3 parts:
a 5-carbon sugar, a
phosphate group, and a
nitrogenous base.
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Nucleic Acids
• There are two
possible pentose
sugars in a nucleic
acid: Ribose and
Deoxyribose.
• DNA has
deoxyribose
• RNA has ribose
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4) Protein
• The R groups have
varying properties: some
are acidic, basic, polar, or
nonpolar in nature.
• Proteins have a diverse
role in biology.
– Some are for transport
(COPI, COPII, actin,
myosin)
– Structure (muscle,
bones)
– Regulation of cellular
activities (cell cycle)
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Protein Organization
• 4 levels of organization
– Primary = individual sequence of amino acids in a
protein.
– Secondary = Hydrogen bonding causes folds and
twists in between AA (-helix,  pleated sheets).
– Tertiary = 3-dimensional folding occurs within the
chain.
– Quaternary = Multiple chains can fold on each
other (Hemoglobin).
4) Protein
• Proteins contain Carbon, Oxygen, Hydrogen,
and Nitrogen.
• Building block of protein is called an Amino
Acid
– AA contain an amino group (-NH2)
– Also contain and carboxyl group (-COOH)
– 20 different amino acids, each differ only in their side
chain (R group).