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Atoms are the
smallest unit of an
element
Three particles
 Protons (+ charge)
 Electrons (- charge)
 Neutrons (no charge)

Nucleus contains
protons and neutrons
 Pure substance made of only ONE type of
atom
 Arranged in periodic table using atomic #
 Atomic # = # of protons OR electrons
 Atomic mass = # of protons + # of neutrons
 Atoms of the SAME element that have a
different # of neutrons
 Ex: Carbon-12,
Carbon-13, Carbon-14
 C-13 and C-14 have
MORE neutrons
(weigh more) than C-12
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Radioactive isotopes have unstable nuclei
that break down at a constant rate over
time
Uses for radioactive isotopes
 Dating of rocks and fossils
 Kills bacteria on food
 Kills cancer
 Trace movements of substances within the body
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A substance formed by combination of
two or more atoms in definite
amounts or ratios
 Ex:
▪ Water (cmpd name), H2O (chem. formula)
 Ex:
▪ Carbon dioxide (CO2) – necessary in large amounts,
▪ Carbon monoxide (CO) – deadly in large amounts

Chemical properties of cmpd are
TOTALLY different than the elements
within it
 Ex: NaCl (Na-sodium-is a soft metal; Cl-
chlorine-is a green poisonous gas) forms
table salt!!!
Solutions
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Solute – the substance that is dissolved
Solvent – the substance in which the
solute dissolves

Ex: Salt Water
▪ Solute = Salt
▪ Solvent = Water
Scale measuring amount of H+
(really H3O+)
 Ranges from 0-14
 Neutral: (pH = 7)

 Human blood
 Pure water

Acidic: (pH = 0-6.9)
 Lemons/lemonade
 Stomach acid

Basic: (pH = 7.1-14)
 Baking soda
 Bleach
 Weak acids/bases that help prevent
sharp pH changes
 Ex: blood has a buffer (to keep it at 6.5-
7.5 pH)
 Ex: When you drink lemonade, your
body produces a buffer to make sure you
blood pH doesn’t lower to acidic levels!
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Like a Buffer for Temperature Change
Cohesion:
 Water sticks to itself (makes drops)
Adhesion:
 Water sticks to OTHER molecules (travels
thru plants)
Hydrogen bonding: (Polar )
 Type of bond which holds water
molecules together
 Universal Solvent (Saliva)
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Symbol: C
Forms Organic Compounds
 Compounds that make up living things
 Also called:
▪ Macromolecules
▪ Polymers
 Carbon has 3 chemical advantages:
1) Can make up to 4 covalent bonds
2) Can bond with many elements
3) Can form long chains
-by bonding to itself
-forms millions of different molecules

Made of two or more smaller molecules
 Monomer + Monomer = Polymer
 Polymers = puzzle
 Monomers = puzzle pieces

Four main types:
1) Carbohydrates
3) Proteins
2) Nucleic acid
4) Lipids
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Made of C, H, and O in a 1:2:1 ratio
Monomers
 Monosaccharide
 Examples: glucose, fructose, galactose

Dimers
 Disaccharides
 Examples: sucrose and lactose
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Polymers
 Polysaccharides
 Examples: starch, glycogen, chitin, and cellulose

Main source of energy for body functions
(through digestion)

Used to build nucleic acids

Structural purposes (cell membrane)
Chitin
Cellulose
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Made of C, H, and O (phospholipids have P)
Triglyceride
 Monomers: 1 Glycerol, 3 Fatty Acid Chains
 Examples: Fats found in adipose tissue
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Phospholipid
 Monomers: 1 Glycerol, 2 Fatty Acid Chains
 Example: Molecules found in cell membrane
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Steroid
 Monomers: 4 Carbon ring structure
 Example: cholesterol, testosterone, estrogen, and
other hormones
Testosterone
Progesterone
Cholesterol

Uses:
 Store Energy Long-Term (blubber)
 Part of Cell Membranes (phospholipids)
 Waterproof Coverings (feathers)
 Chemical Communication (hormones)

Four main categories:
 1) Fats – butter, margarines, crisco
 2) Oils – olive, veggie, canola, corn
 3) Waxes – candles, cosmetics, duck’s
feathers surrounded by this
 4) Steroids – used in communicating b/t
cells
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Made of C, H, O, N and
P

Monomer: Nucleotide
(3 Parts)
Phosphate

Uses:
Sugar
 To store hereditary info
 To pass hereditary info
on to offspring
Nitrogen Base

DNA (Information Storage)
 5 Carbon Sugar : Deoxyribose
 Nitrogen Bases: A, T, G, C
 Phosphate
Phosphate

RNA (Information Transfer)
Sugar
 5 Carbon Sugar: Ribose
 Nitrogen Bases: A, U, G, C
 Phosphate
Nitrogen Base
DNA
RNA
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Made of C, H, O, S, and N
Monomer:
 Amino acids (20 needed in human body)
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Polymer:
 Polypeptide Chain  Protein
 Amino acids are held together by a peptide bond
 Uses:
 Enzymes: Control rate of reactions
 Regulate: cell processes
 Structure: form bones/muscle
 Transport: substances in or out of cells
 Fight disease: Antibodies
Macromolecule
Monomer
Polymer
Carbohydrate
Monosaccharide
Polysaccharide
Protein
Amino acid
Proteins
Lipid
Glycerol AND
fatty acids
Lipids
Nucleic acid
Nucleotide
DNA or RNA
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Chemical reactions are the breaking and
forming of chemical bonds
Reactants- original elements or compounds
Products- ending elements or compounds
Adenine
High Energy Bonds
Adenosine
Ribose
Phosphates

Organisms need E to carry out Reactions
 All an Organism’s Chemical Reactions = Metabolism
▪ Where do they get Energy (E)?
▪ Plants – photosynthesis/sun
▪ Animals – eating food/consuming others

Reaction Types
 Energy Releasing
▪ Reaction is spontaneous (not fast, necessarily)
▪ Activation energy – energy need to get the reaction
started
▪ At the end of the reaction, energy is released into the
environment
 Energy Absorbing
▪ Rxn is not spontaneous
▪ Activation energy- energy needed to get the rxn started
▪ At end of the rxn, energy is absorbed from environment
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Catalyst for the reaction (speeds up it’s rate)
Substrate (reactant) enters the active site of
the enzyme to form an enzyme-substrate
complex
 After the rxn, the product leaves

The enzyme remains unchanged

Speeds up the reaction by lowering activation
energy
DNA replication
Digestion (enzymes in your stomach,
saliva)
 Water removal (from food)
 Carbon dioxide removal (from blood)
 Fat breakdown (detergents)
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