Section 6.2
Chemical ReactionsProcess by which atoms or groups
of atoms in substances are
reorganized into different
substances
Reactants and Products

Reactants – starting materials


Product – ending materials


Left side of equation
Right side of the equation
Arrow indicate process of change
Chemical Reaction

Reactants are reorganized into different
substances


Na + Cl ------ NaCl
Chemical bonds are broken and
reformed

C6H12O6 + O2 ------ CO2 + H2O
Which is a Chemical Reaction
Rust on a chain
 Water boiling
 Wood burning
 Plant production of glucose
 Candle melting

Energy of Reactants

Activation Energy
– the smallest
amount of energy
reactants need to
make products
Exothermic

Energy is released
as heat or light


Heat confirms a
chemical reaction
Energy of products
is LOWER than that
of reactants
Examples
Hand Warmers
 Fire
 Glowsticks
 Cell Respiration

Endothermic

Heat energy is
absorbed

Energy of products
is HIGHER than that
of reactants
Examples
Photosynthesis
 Ice Melting
 Sweat
evaporation
 Cooking

Catalyst

Catalysts lower the activation energy



Not as much energy is needed to form
products
Chemical reactions can happen FASTER
Does NOT increase how much product is
made and it does not get used up in the
reaction
Enzyme

Are BIOLOGICAL
CATALYSTS


Lower activation
energy
Speed up chemical
process in living
organsims
Enzymes
 The reactants that bind to the enzyme are called
substrates.
 The specific location where a substrate binds on an
enzyme is called the active site.
 Substrate and active site have complementary shapes and
allows them to act much like puzzle pieces
Section 6.3
Water and Solutions
Water’s Polarity
Molecules that have a positive pole and
a negative pole, this is called a polar
molecule
 If opposite poles of different molecules
come close together they will attract.
 This attraction leads to hydrogen bonds
– weak interaction between a hydrogen
and fluorine, oxygen or nitrogen

Water

One molecule of water has two covalent
bonds


One bonding the oxygen to each of the
hydrogens
Multiple molecules of water are held
together by hydrogen bonds between
the hydrogen on one molecule and the
oxygen of another
Hydrogen Bond


Where are
the
electrons?
To which
atom are
most located
nearest?
Mixtures with Water
A mixture two or more substance
where each keeps its characteristics.
 A solution is a mixture that has a
uniform composition throughout.
 A solvent is a substance in which
another substance is dissolved.
 A solute is the substance that is
dissolved in the solvent.

Solution or Mixture
Solution or Mixture
Section 6.4
The Building Blocks of Life
Organic Chemistry

The element carbon
is a component of
almost all biological
molecules.
Carbon
 Carbon compounds can be in the shape of
straight chains, branched chains, and rings.
Macromolecules



Carbon atoms can be joined to form carbon
molecules.
Macromolecules are large molecules formed
by joining smaller organic molecules together.
Polymers are molecules made from
repeating units of identical or nearly identical
compounds linked together by a series of
covalent bonds.
Biological Macromolecules
pg 167
Group
Example
Function
Carbohydrates
Glycogen
Energy source
Structural support
Lipids
Fats
Store energy
Provide barriers
Proteins
Hemoglobin –
protein which carries
oxygen throughout
the body
Transport
Speed reactions
Structural support
Make hormones
Nucleic Acids
Building block of
DNA
Store and
communicate genetic
information
Carbon (Organic) Compounds

Carbohydrates- compounds of life
made of C, H and O in a 1:2:1 ratio



Monosaccharides: single sugar
Polysaccharides: many monosaccharides
Importance of Carbohydrates to life
main energy source of all cells- glucose
(C6H12O6)
 energy storage in plant cells- starch
 energy storage in animal cells- glycogen
 cell walls of plants- cellulose

Lipids

Lipids- compounds of life made of lots
of C & H (fats, oils, waxes)


Most lipids do not dissolve well in water
(covalent bonds)
Importance of lipids to life:



long term energy storage
provide structure of cell membranes
chemical messengers: steroids like
estrogen, testosterone, and cholesterol.
Proteins

Proteins- Compounds of life made of
nitrogen, C, O and H



Held together by polarity of water, hydrogen
bonds and interactions of Amino Acids
Amino Acids: building blocks of proteins
Importance of proteins to life:



body structure: muscles, bone, collagen,
cartilage, hair
transport: hemoglobin- red chemical in blood to
transport oxygen
fight diseases: antibodies, control chemical
reactions: enzymes
Nucleic AcidsNucleotides- composed of a sugar, a base
and a phosphate
 Importance of nucleic acids to life:


store and move hereditary or genetic
information within all cells
DNA- two strands that spiral around each
other

stores hereditary information

RNA- one single strand
manufactures proteins
 acts as an enzyme


ATP- single nucleotide with two extra
energy storing phosphate groups (stores
energy temporarily)