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Chapter 2 Basic Chemistry
I. Concepts of Matter and Energy
A. Matter – anything that occupies space and has mass.
Exists as a solid, liquid and gas.
1. Physical changes – do not alter the basic nature. Ex:
ice to water.
2. Chemical changes – do alter composition of
substances. Ex: digestion of food.
B. Energy – massless, does not take up space can only be
measured by its effects on matter. The ability to do
work.
1. Kinetic Energy – energy doing work – moving
objects
2. Potential Energy – inactive or stored energy.
3. Forms of Energy
a. chemical energy – energy stored in bonds of
chemical substances.
b. electrical energy – energy that results from
movement of charged particles.
c. mechanical energy – directly involved in moving
matter. Ex: legs providing mechanical energy.
d. Radiant energy – travels in waves of the
electromagnetic spectrum such as light, radio, xrays and ultraviolet waves.
II. Composition of Matter
A. Elements and Atoms
1. element- substance that can not be broken down into
a simpler substance by ordinary chemical methods.
a. carbon – C, oxygen – O, hydrogen – H, nitrogen –
N, all major components of the body.
b. Periodic table – lists known elements in a specific
order.
c. Atom – building block of an element
d. Atomic symbol – one or two letters represents a
specific element.
B. Atomic Structure
1. protons – (p+) – positive charge, mass = 1amu.
2. Neutrons – (n) – uncharged, mass = 1 amu.
3. Electrons – (e-) – negative charge, mass = 0 amu.
4. Particles with like charges repel each other and
particles with unlike charges attract each other.
5. Planetary model/orbital model pg. 30.
C. Identifying elements
1. Atomic number – number given to each element that
is equal to the number of protons its atom contains:
(Indirectly the number of electrons – because #of
electrons = # of protons.)
2. Atomic mass number = sum of protons and neutrons
contained in the nucleus.
3. Atomic weight – average of mass numbers of all
isotopes of an element.
a. isotope – have same # of protons and electrons but
vary in the # of neutrons. Have same atomic # but
different atomic masses.
b. Radioisotopes – heavier, unstable isotopes that
tend to break down to become more stable.
1. radioactivity – process of spontaneous atomic
decay. Involves the ejection of particles(alpha and beta) or electromagnetic energy
(gamma rays). They are damaging to living
cells.
III. Molecules and Compounds
A. Molecules – two or more elements chemically combined
1. molecular formula – indicates the composition
of the product, showing atomic makeup. Ex:
C6H12O6
2. chemical equation – shows chemical reaction
HCl  H+ + Cl –
B. Compound – two or more different atoms bond
together. Ex: CH 4 (methane) – have properties
different from atoms making them up.
IV. Chemical bonds and chemical reaction
A. Chemical reactions – occur whenever atoms combine
with or dissociate from other atoms.
1. Bond formation – not a physical structure, energy
relationship involving interaction between
electrons.
a. role of electrons
1. energy levels/electron shells – 7 levels
a. shell 1 holds 2 electrons
b. shell 2 holds 8 electrons
c. shell 3 holds 18, subsequent shells hold
larger #’s
2. valence shell – the outermost shell – it’s
electrons determine the chemical behavior of
the atom.
3. “rule of 8’s” or “octet rule” – need 8 electrons
in outer shell to be stable Ex: pg. 33- 35
B. Types of bonds
1. Ionic bonds – form when electrons are
completely transferred from one atom to
another. They are then ions (charged
particles)
a. anions – negatively charged particles.
b. cations – positively charged particles
2. Covalent bonds – atoms share electrons
a. nonpolar – when the electrons are equally
shared.
b. Polar – a molecule with two charged poles.
Ex: water.
3. Hydrogen bonds – extremely weak bonds,
formed when a Hydrogen atom bound to N or
O is attracted by another atom, forming a
bridge. Ex: Common water.
a. intramolecular bond – bind different parts
of the same molecule together. Ex:
proteins
C. Patterns of chemical reactions
1. synthesis reactions – two or more atoms or molecules
combine to form a larger more complex molecule.
A + B  AB
a. energy absorbing reactions
b. underlie all anabolic (constructive) activities in the
body.
2. Decomposition reaction – occurs when molecules are
broken down into smaller molecules atoms or ions
a. energy releasing reaction AB  A + B
b. underlie all catabolic reactions (destructive )
activities in the body.
3. Exchange reaction – involves both synthesis and
decomposition reactions.
a. bonds are made and broken
AB + C  AC + B and
AB + CD  AD + CB
V. Biochemistry : The Chemical Composition of Living Matter
A. Major classes of molecules:
1. Organic compounds – carbohydrates, lipids, proteins,
nucleic acids.
2. Inorganic compounds – lack carbon, are simple
molecules; water, salts many acids and bases.
B. Inorganic Compounds
1. water – most abundant inorganic compound in body
a. has high heat capacity – absorbs and releases large
amounts of heat.
b. Excellent solvent
c. Important reactant
d. Serves as a base for body lubricants.
e. Serves a protective function
2. salts – ionic compound that dissociates into charged
particles (other than hydrogen or hydroxyl ions)
when dissolved in water.
a. all salts are electrolytes- substances that conduct an
electrical current in solution.
3. Acids – proton donor – a substance that can release H
ions in detectable amounts.
a. acids found or produced in body: hydrochloric
acid, acetic acid, carbonic acid.
b. Strong acids ionize completely.
c. Weak acids ionize incompletely.
4. Bases – proton acceptor, Hydroxyl ion is released
(OH).
a. when acids and bases react, they form salt and
water. Neutralization reaction.
b. pH scale – based on the number of H ions in
solution. Scale is 1-14. 1 most acidic, 7 neutral, 14
most basic. Normal blood pH range is 7.35 –
7.45.
C. Organic compounds
1. carbohydrates – include sugars and starches. Contain
C,H, and O. “hydrated carbon”.
a. classified according to size
1. monosaccharide – one sugar. (glucose, fructose
and galactose)
2. disaccharide – two sugars. Formed by
dehydration synthesis – water lost.
Ex: sucrose  glucose-fructose
Lactose glucose-galactose
Maltose  glucose-glucose
*broken down by hydrolysis – water added –
simple sugar is released.
3. polysaccharides- “many sugars” –long branching
chains of sugar.
a. starch – storage polysaccharide formed in
plants. (grain products, potatoes, carrots etc.)
b. glycogen – smaller found in animal tissue.
(linked glucose units) – muscles and liver.
2. Lipids
a. neutral fats (triglycerides)
1. fatty acids
2. glycerol
 fatty acids can be saturated (single bonded
carbons) or unsaturated fats (some double or
triple bonded carbons).
b. phospholipids – found in cell boundaries
1. 2 fatty acids
2. glycerol
3. phosphorus containing group
c. steroids – four interlocking rings – made mostly of
C and H
1. cholesterol – take in through diet and made by
liver. – found in membranes
3.Proteins – functions vary – construction materials, cell
functions.
a. amino acids- building blocks of proteins. (20
different amino acids)
b. polypeptide chain – many amino acids hooked
together by dehydration synthesis. The bond
between the amino acids is called a peptide
bond.
c. Proteins – classified as:
1. fibrous – strandlike – structural proteins
2. globular – mobile functional proteins, held
together by H bonds (weak). – active sites.
Figure 2.16 “surface areas where other
molecules fit”.
3. Enzymes- globular – act as catalysts –
substances that increases the rate of the
chemical reaction w/o becoming a part of
the product or being changed itself.
- ase. (suffix) – indicates that it is an enzyme.
4. Nucleic acids – C,H, O, P, N
a. made up of genes.
b. Determine protein formation
c. Made up of nucleotides
*three basic parts of a nucleotide:
1. nitrogen containing base
2. pentose sugar
3. phosphate group
 five varieties of bases:
1. adenine (A)
2. guanine (G)
3. cytosine (C)
4. thymine (T)
5. uracil (U)
d. two major kinds of nucleic acids:
1. DNA – deoxyribonucleic acid
2. RNA – ribonucleic acid
e. DNA – has two roles – found in the nucleus.
– double stranded, double helix, ( A-T), (C-G)
1. replicates before cell divides to give each
new cell genetic information.
2. Provides instructions for building
proteins in body.
f. RNA – outside nucleus
1. carries out orders for protein synthesis
issued by DNA, single stranded, (A-U),
(C-G)
2. three types of RNA –
a. messenger RNA
b. ribosomal RNA
c. transfer RNA