The Chemistry of Life 33
Career
Focus
There are many career opportunities for individuals interested in chemistry. Lab
Technicians work as assistant researchers in industry and universities.^
● High School Teachers specialize in teaching the basic understanding of chemistry to
young adolescents.^
● College Professors conduct research, teach adults upper-level principles of chem-
istry, and mentor undergraduate and graduate chemical research projects.^
● Organic Chemists specialize and study the chemistry of the carbon atom and all the
compounds that have carbon as part of their molecular structure.^
● Environmental Chemists study the effects of chemical pollution of the environment.● Biochemists study the chemical basis of life chemistry in genetics, molecular- biology, microbiology, or food technology.
Summary Outline
INTRODUCTION
- Because the body’s cells, tissues, and organs are
all composed of chemicals and function through
chemical reactions, it is necessary to understand
some basic chemistry.^
- Chemistry is the science that studies the elements,
their compounds, the chemical reactions that occur
between elements and compounds, and the mo-lecular
structure of all matter.
ATOMIC STRUCTURE
- Atoms are the smallest particles of elements that
maintain all the characteristics of that element and
enter into chemical reactions through their
electrons.^
- An atom consists of a nucleus containing positively
charged protons and neutral neutrons.^
- Electrons have a negative charge and orbit the nu-
cleus of an atom in levels at some distance from the
compact heavy nucleus.
ELEMENTS, ISOTOPES, COMPOUNDS
- An element is a substance whose atoms all contain
the same number of protons and the same number of
electrons. Atoms are electrically neutral.^
- A compound is a combination of the atoms of two
or more elements.
3. An isotope is a different kind of atom of the same
element- where the number of neutrons in the
nucleus varies.^
4.^ Carbon is the element found in all living matter.^ - The periodic table of the elements arranges
elements- in categories with similar properties.
BONDS AND ENERGY- Atoms combine chemically with one another to form
bonds by gaining, losing, or sharing electrons.^ - An ionic bond is formed when one atom gains
electrons while the other atom in the bond loses
electrons. Ionically bonded molecules disassociate
when immersed in water. The mineral salts form
ionic bonds.^ - A covalent bond is formed when atoms share
electrons-. Carbon, oxygen, hydrogen, and nitrogen
form covalent bonds. These bonds do not dissociate
when placed in water.^ - Hydrogen bonds are weak bonds. They help hold
water molecules together and bind other molecules
into three-dimensional shapes.^ - Molecules furnishing electrons during a chemical
reaction are called electron donors; those that gain
electrons are called electron acceptors.^ - Bonds contain energy. These are the electrons that
contain the energy of a chemical bond.^ - Special molecules called electron carriers accept
electrons for a short period of time and use the en-
ergy of the electrons to make ATP molecules.