BIOCHEMISTRY NOTES Pre AP
I. Chemistry—study of what substances are made of and how they change and combine (text pages 35 – 43)
A. Atom – fundamental unit of matter
1. Subatomic particles:
no = neutron
p+ = proton
e- = electron
B. Element - each different kind of atom is a different element
1. Examples: C = carbon
H = hydrogen
O = oxygen
N = nitrogen
C. Compound - two or more elements chemically combined in definite proportions
1. Examples: CO2
H2O
NaCl
C6H12O6
2. Molecules - types of compounds made of nonmetals only
isomers – same molecular formula; different structural formula
D. Chemical reactions – process leading to changes in matter
2 H2 + O2
2 H2O
(reactants)
(products)
E. Compounds are classified into two broad groups:
1. Inorganic Compounds – come from nonliving substances ( in = not organic = living)
2. Organic Compounds – come from living substances
II. Biochemistry – chemistry of living organisms (text pages 44 – 53)
A. Organic compounds – compounds made by cells and containing carbon
1. Example: C6H12O6 Glucose
2. Exception: CO2 Carbon Dioxide
3. Organic compounds in living cells are usually complex compounds that are so large they are
called macromolecules (giant molecules) or biomolecules
4. Macromolecules are formed by process called polymerization – smaller units called monomers join
together to form polymers
5. Four groups of organic compounds:
Draw picture to remember:
a. carbohydrates
b. proteins
c. lipids
d. nucleic acids
III. Carbohydrates
A. Provides energy for all organisms — main source of energy for cells
B. Most carbohydrates are manufactured from plants by photosynthesis.
C. Structure: contains the elements C, H, and O usually in ratio of 1 : 2 : 1
EXAMPLE: C6H12O6 = 6 C + 12 H + 6 O = 1 : 2 : 1 ratio of atoms
GLUCOSE 
D. Food Sources: Fruits, Vegetables, Grains, Pasta, Rice, Sugar, Cookies, Cakes, etc…
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E. Three groups of carbohydrates:
1. Monosaccharides = single sugar; basic structural unit from which larger carbohydrates are built
(mono = one
sacchar = sugar)
Examples: sugars usually end in -ose
a. glucose – C6H12O6 - most common sugar, in every cell – produced by green plants
b. fructose -- C6H12O6 - sugar in fruits
c. galactose -- C6H12O6 - sugar in milk
*Reminder - These are isomers; same molecular formula, different
structural formula 
2. Disaccharide – double sugar (di = two)
a. sucrose - cane sugar (table sugar)
b. chemical reaction: 2 monosaccharides joined together to make a disaccharide
glucose + fructose
sucrose + water
C6H12O6 + C6H12O6
C12H22O11 + H2O
When water is released in a
chemical reaction = dehydration
synthesis
Sucrose
3. Polysaccharide – many sugars (poly = many)
Examples:
a. starch – polysaccharide stored in plants
potatoes, pasta, grains (bread, rice)
b. glycogen –polysaccharide stored in animals – stored in liver and muscles
c. cellulose – polysaccharide that gives support and structure to plant cells (fiber)
most abundant organic chemical on earth
Starch
What is the purpose of storing sugars as polysaccharides in plant and animal tissues?
Plants store excess sugars as fruits and vegetable for heterotrophs and also for times when the plant
cannot undergo photosynthesis.
Animals store sugars so they have the ability to respond to “fight or flight” situations.
Take 5 – Complete concept map for Carbohydrates
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IV. Monomers/Polymers
1. General term for any small compounds that can be joined together to make larger compounds -monomer
example: glucose = monomer of a carbohydrate.
-many glucose molecules can be added together by dehydration synthesis to make a
polysaccharide
2. General term for any large compound formed by combining monomers -- polymer
example: Starch, Glycogen, Cellulose = Polymer
-These molecules are polymers made when many glucose molecules chemically
combine.
Everyday Example:
Monomer 
Polymer 
V. Proteins (also called peptides or polypeptides)
A. Needed for growth, maintenance and repair of living materials
1. cell membrane, skin, nails, hair, bones and muscles made of protein
B. Fight disease – antibodies made of proteins
C. Control rate of chemical reactions in cells – enzymes made of proteins
D. Food source – lean meat, fish, eggs, cheese, nuts, beans, dairy
E. Structure:
1. proteins are polymers of molecules called amino acids
monomer = amino acid
polymer = protein
2. contain the elements C, H, O and N
Dehydration Synthesis of Proteins
F. 20 different amino acids combine in different ways to make up thousands of different proteins
G. Examples of protein structures:
Take 5 – Complete concept map for Proteins
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VII. Enzymes
A. Enzymes are catalysts in living organisms
catalyst – substance that speeds up a chemical reaction
B. Most enzymes are made of proteins
C. Enzymes are not changed in a reaction and can be reused
D. Enzymes are specific – speed up only one type of chemical reaction
E. Lock and Key hypothesis – an explanation of how an enzyme works
F. Substrate – substance upon which a certain enzyme acts
G. Naming enzymes – add “ase” to substrate name
a. maltose is substrate – maltase is enzyme
b. protein is substrate – protease is enzyme
H. One important function of enzymes is speeding up digestion of food
I. Enzyme Diagram:
*Note: Anabolic – to build
Catabolic – to break down
The _____________
gets used up, but the
________________
can be used again
indefinitely
Take 5 – Complete concept map for Enzymes under the Protein Biomolecule
V. Lipids
A. Functions:
1. energy storage – twice as much energy/ g. as carbohydrates
2. makes up part of the cell membrane
3. hormones are lipids – estrogen and testosterone
B. Examples:
1. Fats – solid at room temperature – butter, lard (animal fat)
2. Oils – liquid at room temperature – corn oil, olive oil (plant fats)
3. Phospholipids and cholesterol – makes up cell membranes
4. Steroids – type of hormone that can cross cell membrane directly into cells
(anabolic steroids – handout)
5. Waxes – on leaves of plants to make them waterproof
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C. Structure: fats and oils
1. Composed of glycerol and 3 fatty acids
2. Contain the elements C, H and O
When glycerol + fatty acids combine
to form 1 fat molecule, H2O is
released = dehydration synthesis
D. Dietary importance
1. Saturated fats – generally come from animal fats
a. Bad for you – deposited in arteries – cause heart disease
Saturated with hydrogens (H)
No double bonds in fatty acid chain
2. Unsaturated fats – generally from plant oils
a. Better for you
Have one or more double bonds
in fatty acid chain
3. Cholesterol – 2 sources
a. your body produces it – essential to life: helps produce certain hormones and part of cell
membranes in animals
b. you consume it in food
1. bad cholesterol – LDL (low density lipoprotein) – goes to cells, excess deposited in arteries
2. good cholesterol – HDL (high density lipoprotein) – gets rid of excess LDL’s in arteries
Take 5 – Complete concept map for Lipids
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VIII. Nucleic Acids
A. Function is to store and transmit genetic information from parent to offspring
B. Examples: DNA and RNA (Nucleotide)
C. Contains the elements: C, H, O, N, P
D. Nucleic acids are made from monomers called nucleotides.
The 3 components of a nucleotide are
1. 5 – carbon sugar (Deoxyribose or Ribose)
2. Phosphate Group
3. Nitrogenous Base
E. Food source: All living food sources contain nucleic acids. Food
sources high in nucleic acids include items such as fish, fruits, nuts, algae, and mushrooms.
Take 5 – Complete concept map for Nucleic Acids
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Function:
main source of energy for cells
energy storage in plants and animals
support and structure for plant cells
Carbohydrates
Structure:
Elements: C, H, O
Draw:
Examples:
3 groups:
 mono:glucose,
fructose, galactose
 di: sucrose
 poly: starch, glycogen,
cellulose
Dietary Examples:
= Glucose
monomer = monosaccharide
(glucose)
polymer = polysaccharide
(starch)
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Function:
Enzymes:
-growth, maintenance and
repair of cells
-fight disease
-control rate of chemical
reactions
Function: control rate of
chemical reactions
Diagram:
Proteins
Structure:
Examples:
Antibodies, Enzymes, Hair,
Nails, Muscle Fibers
Elements: C, H, O and N
monomer = amino acid
polymer = protein
Dietary Examples: meat,
fish, eggs, cheese, nuts,
beans, dairy
Draw:
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Function:
energy storage
makes up cell membranes
hormones are lipids
Lipids
Structure:
Elements: C, H and O
Monomer: glycerol and 3
fatty acid chains
Draw:
Examples:
fats and oils
phospholipids and
cholesterol
steroids
waxes
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Function:
-store and transmit genetic information from
parent to offspring
Nucleic Acids
Examples:
Structure:
DNA and RNA
Monomer: Nucleotide
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