Chapters 2-5
 Know
chemistry vocabulary (review packet)
 Difference
between types of bonds and how
many bonds elements form (CHNOPS)
• hydrogen (weak bonds between
molecules)
• ionic (lose electron)
• covalent (share electrons)
 polar v. nonpolar molecules




polar molecule...results in “v” shape
know properties of water (cohesion, adhesion, surface tension)
• high heat capacity
• solid less dense than liquid (ice floats)
know differences between solution, solute, solvent, aqueous
solution; hydrophilic and hydrophobic
• Water is an excellent solvent.
 Ionic and polar substances dissolve easily in water
 nonpolar substances do not dissolve in water
Acids, bases, pH and buffers
**Think about all of these concepts in terms of living systems. How
do all of these concepts allow a living organism to function? or
cause an organism to not function successfully?


Carbon is the most important element in living things.
“Carbon-based life forms”
Carbon has the ability to make 4 bonds...resulting in
incredible versatility in bonding with other elements (it
can make large, complex molecules)
• Hydrocarbons (carbon and hydrogen only)--fossil fuels
• Isomers (structural v. geometric)
 Structural- differ in covalent arrangement of atoms
 Geometric- differ in spatial arrangements
 Enantiomer- mirror images
• can form branches, chains and rings

polymer--long molecule made of smaller building blocks
• carbohydrates, proteins, nucleic acids. **lipids**

monomer--building blocks that make up polymers

synthesis of polymers
• dehydration reactions--covalent bonds between molecules with
the loss of a water molecule

breakdown of polymers
• hydrolysis--molecules are broken using water (reverse of
dehydration rxn)

enzymes: macromolecules that speed up chemical reactions
 Functional
Groups--chemical groups
attached to carbon skeleton that
determine function and unique
properties of large molecules
 Figure
4.9
 testosterone
estradiol
vs.

Functional Groups
• Each has specific chemical properties, when attaches
to larger molecule it gives those properties to that
molecule
• A single molecule may contain many different
functional groups
• Determines molecular shape and reactivity

Hydroxyl (-OH)
• Alcohols
• Polar
• Hydrogen bond with water
• Carbs, proteins, nucleic acids and lipids



Carbonyl (-CO)
• ketones and aldehydes
• Component of sugars
• Carbohydrates, nucleic acids
Carboxyl (-COOH)
• important part of amino acids
• organic acids (ie. vinegar)
• Proteins, lipids
Amino (-NH2)
• important part of amino acids
• Basic (H+ acceptor)
• Proteins, nucleic acids



Sulfhydryl (-SH)
• present in certain amino acids (methionine and
cysteine)
• Forms disulfide bridge (protein structure)
• proteins
Phosphate (-OPO3)
• part of cellular energy sources (ATP, ADP)
• Acidic
• Nucleic acids
Methyl (-CH3)
• part of DNA molecules (gene expression)
• proteins
 Have
the general formula CnH2nOn
 Functions
• Source of stored energy
 Used to transport energy
• Structural molecules
 Used as building blocks for other macromolecules
• Recognition or signaling molecules that trigger
specific responses
 Monosaccharide: simple
sugar
• Pentose sugar (5 carbon) C5H10O5
 Ribose, deoxyribose
• Hexose sugar (6 carbon) C6H12O6
 Glucose**, fructose, galactose (isomers)
 Fructose—”fruit sugar”, very sweet!
 Example of how arrangement of carbon atoms change
molecule properties
 Polysaccharide: polymer
of monosaccharides
• Formed by glycosidic linkages (covalent bond that
results from dehydration reaction—lose H2O)
 “sugar bond”
• Sucrose (glucose + fructose)—disaccharide
 Used in carbohydrate transport
• Lactose (glucose + galactose)—disaccharide
 Milk sugar
 Some individuals are missing the enzyme to break down this
sugar…”lactose intolerance”
• Starch (glucose+ glucose+ glucose….)
 Storage polysaccharide (plants)
 Molecules broken by hydrolysis for energy
 Long chain of alpha-glucose molecules
• Glycogen-- highly branched polymer of alpha-glucose
 Storage polysaccharide (animals) in liver and muscles
 “animal starch”
• Cellulose—unbranched polymer of beta-glucose
 Structural polysaccharide (plant cell wall)
 Not easily broken down by most organisms
 Herbivores have special bacteria to do this
• Chitin (modified glucose chain)
 Structural material found in arthropods (insects) and fungi
 Makes up exoskeletons

Group of molecules that are insoluble in water

May be storage fats, oils, steroids, or waxes

Important component of cell membranes
 Hydrophobic
• Phospholipids (phosphate attached to glycerol)
 2 FA instead of 3
• Polar and nonpolar ends of molecule (hydrophilic and
hydrophobic regions)
 Phosphate hydrophilic

Serve as a long-term form of energy storage
• Very efficient molecule for storage
 Made
of two components:
• Fatty acid “tail of molecule”
 Long chain hydrocarbons with carboxyl group
 Chain is usually 14-20 carbons long
• Glycerol “head of molecule”
 Three –OH groups (hydroxyl)
 alcohol
 Holds molecule together
 FA and glycerol held together by an “ester linkage”
 Carboxyl + Hydroxyl
“Triglyceride”- one glycerol plus 3 FA (basic fat/oil)
 Saturated FA
• No double bonds (carbon atoms)
• Maximum number of hydrogens
• Solid at room temperature (animal fats-- butter)
 Unsaturated FA
• One or more double/triple bonds (carbon atoms)
• Liquid at room temperature (plant fats--oils)
• Monounsaturated (one double/triple bond)
• Polyunsaturated (more than one double/triple bond)
• “trans fats” partially hydrogenated unsaturated fats .
Created by adding hydrogen and breaking
double/triple bonds (health risks)
 Waxes
• Alcohol + unsaturated oil
 Steroids
• 4 carbon rings
• Attached functional groups make them unique
(testosterone vs. estrogen)
• Ex. Cholesterol (component of cell membranes
and precursor to other steroids)
 DNA
and RNA
• Genetic information
inherited from parents
• RNA used in protein
synthesis
 Polymers
of
nucleotides
• Sugar, phosphate,
nitrogenous base
 Every
dynamic function of an organism
depends on proteins!
 Functions include: (Fig. 5.15)
• Transport (hemoglobin)
• Structure (collagen)
• Enzymes (trypsin)
• Movement (myosin)
• Defensive (immunoglobin)
• Hormones (insulin)
• Storage (caesin)
 Proteins
are made of monomers called amino
acids.
• 20 amino acids exist in nature (fig. 5.16)
• Each has an amino and carboxyl group
 Chains
of amino acids are called
polypeptides
• Amino acids are linked together with a peptide bond
 Each polypeptide has an amino group at one end and a
carboxyl group at the other
 The unique properties and structure are determined by
the side groups of the amino acid (unique to each a.a.)
A
polypeptide chain becomes a protein once
it has undergone modification and folding
(3-dimensional)
• The 3-D structure is determined by the unique
sequence of amino acids. (each protein is folded
uniquely)
• Four Levels (fig. 5.20)
 Primary—chain of a.a. (not folded)
 Secondary—H-bonds form between a.a. (making helix or
pleated sheet)
 Tertiary– 3-D shape formed from reactions between a.a.
side chains (sulfide bridges)
 Quaternary– multiple polypeptides (chains) linked
together in 3-D structure
 Proteins
exposed to
excessive heat, pH
changes, chemical,
or other
environmental
changes may
change their shape
and become
ineffective
(misshapen)