Download Basic Chemistry

Chemical
Basis of Life
Matter and Energy
Matter- anything that occupies space
and has mass
solid, liquid, gas
Mass-amount of matter a substance
contains
Energy
potential, kinetic
light, heat, electrical, chemical
Basic Molecular Structure
Matter is comprised of elements, 92 of
which occur naturally
Elements cannot be broken down into
simpler substances
Identified by chemical symbols
Oxygen, carbon, hydrogen, and nitrogen
make up 96% of body’s mass
Compounds are combination of two or
more elements
Compound & Mixtures
Compound
Mixtures
Combined
Combined
chemically
physically
Alters properties Retains
of individual
properties of
components
individual
components
Proportions may
Combined in
exact proportions vary
Types of mixtures
Solutions - homogeneous mixture
Solute = dissolved substance
Solvent = dissolving medium
Concentrations
percent
molarity
Colloids (emulsions) - undergo sol-gel
transformations
Suspensions - visible solutes that settle
What is an atom?
-smallest part of an element
showing characteristics of that
element
ATOMIC STRUCTURE
a tomos = “not cut”
Subunits
protons-located in the
nucleus (+)
neutrons-located in the
nucleus (0)
electrons-located in
energy shells (-)
ATOMIC CHARACTERISTICS
Atomic number - number of protons
in the nucleus
Mass number - number of protons
plus the number of neutrons
Atomic weight (mass) - sum of the
number of protons,neutrons, and
electrons
Number of protons equal the number
of electrons
A complete atom is
electrically neutral.
There is NO NET CHARGE!
Atomic Structure
Isotopes
atoms with the same numbers of
protons but have different numbers
of neutrons
isotopes of an element react in
the same manner chemically
Radioisotopes
Heavier isotopes are usually
radioactive
Examples
Carbon 14
Iodine -131
Radium - 226
Cobalt - 60
Electron shells
electrons orbit the nucleus of an
atom in shells/energy levels
1st level - holds 2 e’s
2nd level - up to 8 e’s
3rd level - up to 18
 number and arrangement of
electrons determine if an atom is
chemically stable
CHEMICAL BONDS
A. Chemical bonds and electrons
1. chemical bonds are a union
between atoms caused by the
sharing or exchange of electrons.
2. the type of bond is determined
by the arrangement of the electrons
in orbit around the nucleus.
3. electrons are attracted to protons,
but repelled by other electrons
4. electrons are arranged in orbits
(orbitals) around the nucleus.
5. the electrons in the outermost orbital
are called the valence electrons
6. valence electrons determine the
chemical reactivity of an atom.
7. octet rule - atoms form bonds to
have 8 electrons in their valence shell
CHEMICAL REACTIONS
Molecule - two or more atoms
joined together ex. H-H; O=O
Compound - combination of atoms
of two or more elements ex.
CO2, H2O
Chemical Equations
Reactants – left side of the equation
Products – right side of the equation
Molecular Formula
Example
C6H12O6 + 6O2 ----- 6CO2 + 6H2O +
Energy
Patterns of Chemical Reactions
Synthesis = combination
Decomposition = breakdown
Displacement = reactants exchange
Oxidation Reduction
reactants lose or gain electrons
oxidized - loses electrons
reduced - gains electrons
Factors affecting reactions
Temperature
Particle Size
Concentration
Catalysts
CHEMICAL BONDS
Covalent - involve the sharing
of electrons between atoms
Ionic - bonding involving the
loss or gain of electrons thus
forming ions
cation (+)
anion (-)
Polar covalent - due to the
unequal sharing of electrons
between atoms
Hydrogen - type of covalent
bond due to sharing of hydrogen
electrons with neighboring
hydrogen atoms
INORGANIC MOLECULES
Electrolytes
Acids
Bases
Salts
pH
Water
ELECTROLYTES
Substances that ionize and
dissociate in water and are
capable of conducting an
electrical current
Form charged particles (ions) in
solution
Include acids, bases, and salts
ACIDS and BASES
Acid = substance that releases
hydrogen ions (H+) in solution
Acts as a proton donor
HCl ----> H+ + Cl-
Base = substance that dissociate
in solution into hydroxide (OH-)
Acts as a proton acceptor
NaOH ---> Na+ + OH-
pH - measure of acidity or
alkalinity
pH 7.0 - neutral
acidic - pH < 7.0
basic - pH > 7.opH = - log [H+]
pH - range 0 - 14
body fluids = 7.35-7.45 (7.40)
SALTS
Acids and bases react with other to
form salts when mixed in equal
concentrations
HCl + NaOH
H2O + NaCl (salt)
WATER
Excellent solvent
Polarity
Serves as a reactant
Important lubricant
High heat of vaporization
High heat capacity
ORGANIC MOLECULES
Contain carbon atoms linked to
each other in chains or rings
 -carbohydrates, proteins,
lipids, nucleic acids
CARBOHYDRATES
INCLUDE SUGARS AND
STARCHES
PROVIDE MOST OF CELL’S
ENERGY
CARBON - HYDROGEN - OXYGEN
1 : 2 : 1 RATIO
Monosaccharide
simple sugars
contain 3-7 carbon atoms
ex. glucose, fructose, galactose
Disaccharides
are formed when 2 monomers
are hooked together by
dehydration synthesis reactions
ex. sucrose (table sugar);lactose
(milk sugar)
Carbohydrates/Polysaccharides
Complex sugars
Very large macromolecules formed
when long chains of simple sugars are
hooked together
Glycogen - storage form of glucose in
animals
Starch - storage form of glucose in
plants
PROTEINS
Amino acids are the building blocks of
proteins
Contain carbon, hydrogen, oxygen,
nitrogen
20 amino acids occur naturally
Essential for cell structures and
function
enzymes, receptors, blood
proteins, structural support
PROTEIN STRUCTURE
LEVELS
Primary structure
H
Secondary structure
l
NH2 - C - COOH
Tertiary structure
l
Quaternary structure
R
LIPIDS
Contain carbon, hydrogen,
oxygen but not in a 1:2:1 ratio
Non-polar molecules that will not
dissolve in water
Functions as energy source,
structural support, integral part of
membrane
TYPES OF LIPIDS
TRIGLYCERIDES
fats/oils
saturated fatty acids
unsaturated fatty acids
Phospholipids
important membrane component
amphipathic
Steroids
sex hormones
cholesterol
Eicosanoids
prostaglandins
involved in blood clotting,
inflammation, and contractions
NUCLEIC ACIDS
DNA - deoxyribonucleic acid
RNA - ribonucleic acid
Consist of nucleotides
5 carbon sugar
nitrogenous base - (adenine,
thymine, cytosine, guanine, or
uracil (only in RNA)).
phosphate group
ATP
Adenosine Triphosphate
Main energy carrier for individual
reaction needs