2
CHAPTER SUMMARY
Chapter 2 provides an overview of basic biological chemistry. Although this is often a topic students
dread, it is necessary to convey the importance of physical chemistry reactions and biochemical
metabolic pathways in physiology. This chapter begins with the fundamental concepts related to
matter and energy, then proceeds to show the breakdown of matter into its component parts. A
discussion of the periodic table reveals the way in which elements are arranged by properties, and
provides a means for determining characteristics of certain elements based on their position on the
periodic table. The four most abundant elements in all living organisms (i.e., carbon, oxygen,
hydrogen, and nitrogen) are emphasized.
Atomic structure is presented next, and the planetary and orbital models provide a
framework upon which students begin to build their understanding of atoms. Atomic number,
atomic mass number, and atomic weight are discussed, followed by comments on the characteristics
of isotopes and their role in health care assessment and management. The concepts presented, relative
to atomic structure, lead naturally into a discussion of molecules and compounds. Chemical bonds and
reactions are presented as a means by which molecules or bonds are continuously formed and
destroyed. The differences between ionic, covalent, and hydrogen bonds are all discussed, as are
synthesis and decomposition reactions.
The final section of this chapter provides an overview of biochemistry. The
differences between organic and inorganic compounds are presented, along with applied examples of
each. Water is noted to be the most abundant compound in the body, which helps students
understand its role as the universal “solvent” of life. Explanation of the reactions of acids and
bases initiates the discussion of biochemical reactions in the body. The types of organic
compounds (i.e., carbohydrates, lipids, proteins, and nucleic acids) further the concepts as students
begin to see the importance of the proper functioning of these compounds in all body processes.
SUGGESTED LECTURE OUTLINE
I.
CONCEPTS OF MATTER AND ENERGY (pp. 26–27)
A.
Matter—occupies space and has mass (p. 26)
1.
States Of Matter
a.
Solids—bones, teeth
b.
Liquids—blood plasma, interstitial fluid
c.
Gases—oxygen, carbon dioxide
2.
Changes In Matter
a.
Physical Changes—do not alter composition of substance
i.
Solid ice to liquid water to water vapor
b.
Chemical Changes—do alter composition of substance
i.
Fermentation
ii.
Digestion
B.
Energy—does not take up space and does not have mass (pp. 26–27)
1.
Kinetic Energy—active energy
2.
Potential Energy—inactive (stored) energy
3.
Forms Of Energy—four
4.
II.
a.
Chemical Energy—stored in chemical bonds
b.
Electrical Energy—movement of charged particles
c.
Mechanical Energy—directly involved in moving matter
d.
Radiant Energy—electromagnetic spectrum
Energy Form Conversions
a.
Adenosine triphosphate (ATP)
COMPOSITION OF MATTER (pp. 27–32)
A.
Elements and Atoms (pp. 27–29)
1.
Major Elements
a.
Oxygen
b.
Carbon
c.
Hydrogen
d.
Nitrogen
2.
Lesser Elements
a.
Calcium
b.
Phosphorus
c.
Potassium
d.
Sulfur
e.
Sodium
f.
Chlorine
g.
Magnesium
h.
Iodine
i.
Iron
3.
Trace
B.
Atomic Structure (pp. 29–30)
1.
Protons
2.
Neutrons
3.
Electrons
4.
Planetary and Orbital Models of an Atom
C.
Identifying Elements (pp. 30–32)
1.
Atomic Number—number of protons in nucleus
2.
Atomic Mass Number—number of protons and neutrons in nucleus
3.
Atomic Weight and Isotopes
a.
Isotopes—same number of protons and electrons, but vary in
number of neutrons
b.
Atomic weight—equal to atomic mass
III.
MOLECULES AND COMPOUNDS (pp. 32–33)
A.
Molecule—two or more atoms of same element bind together
1.
H (atom) + H (atom)  H2 molecule
B.
Compound—two or more different atoms bind together
1.
4H + C = CH4 (methane)
IV.
CHEMICAL BONDS AND CHEMICAL REACTIONS (pp. 33–39)
A.
Bond Formation (pp. 33–37)
1.
Role of Electrons
a.
Electron shells (energy levels)
b.
Valence shell—outermost electrons involved in bonding
i.
Rule of Eights—eight electrons fill valence shell
c.
Ionic Bonds—transfer of electrons such as with sodium and
chloride atoms
i.
Salts—compounds formed by ionic bonding
ii.
Ions—positively or negatively charged particles
Covalent Bonds—sharing of electrons such as between carbon and
carbon, and carbon and hydrogen
i.
Single covalent bonds
ii.
Double covalent bonds
iii.
Polar covalent bonds
iv.
Nonpolar covalent bonds
e.
Hydrogen Bonds—weak attraction by another atom seeking an
electron
Patterns of Chemical Reactions (pp. 37–39)
1.
Synthesis Reactions—two or more smaller atoms or molecules combine to
form larger and more complex molecules
a.
Amino acids join together to form a protein
2.
Decomposition Reactions—molecule is broken down into smaller
molecules, atoms, or ions by breaking of chemical bonds
a.
Glycogen is broken down to release glucose units
3.
Exchange Reactions—involve both synthesis and decomposition reactions
whereby bonds are both made and broken
a.
Glucose and ATP form glucose phosphate and ADP
d.
B.
V.
BIOCHEMISTRY: THE CHEMICAL COMPOSITION OF LIVING MATTER (pp. 39–52)
A.
Inorganic Compounds (pp. 39–42)
1.
Water
a.
High Heat Capacity
b.
Polarity/Solvent Properties
c.
Chemical Reactivity
d.
Cushioning
2.
Salts—all are electrolytes
3.
Acids and Bases
a.
Characteristics of Acids—proton donors
b.
Characteristics of Bases—proton acceptors
c.
pH: Acid-Base Concentrations
B.
Organic Compounds (pp. 42–52)
1.
Carbohydrates—ratio of two hydrogen atoms to one oxygen atom
a.
Monosaccharides—single-chain or single-ring simple sugars
b.
Disaccharides—double sugars joined by dehydration synthesis
c.
Polysaccharides—long branching chains of simple sugars
2.
Lipids—carbon and hydrogen atoms far outnumber carbon atoms
a.
Triglycerides—neutral fats
b.
Phospholipids—phosphate-containing group takes the place of one
fatty acid chain
c.
Steroids—four interlocking rings
3.
Proteins—20 common amino acids are building blocks of body cells
a.
Fibrous and Globular Proteins
b.
Enzymes and Enzyme Activity
4.
Nucleic Acids
a.
Nucleotides
b.
Deoxyribonucleic Acid (DNA)
c.
Ribonucleic Acid (RNA)—single nucleotide strands
5.
Adenosine Triphosphate (ATP)
a.
Universal chemical energy used by all body cells
b.
High-energy phosphate bonds broken by hydrolysis releases energy
for work such as muscle contraction
c.
d.
Energy liberated during oxidation of foods continually regenerates
ATP from adenosine diphosphate (ADP) and inorganic phosphate
(Pi)
ATP-driven cellular work