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BIOLOGY SEMESTER ONE
UNIT 2
CHECKLIST WEEK 2: THE CHEMICAL CONTEXT OF LIFE
In this module you will review the chemistry of life. Biological structures and processes are
reliant on the properties and behaviour of the molecules they are made of. Atoms— the
smallest units of chemical compounds— are what elements are made of, and the chemical
bonds between them dictate the formation and function of the molecules they create when
they bond. The making and breaking of the bonds between atoms also contributes to the
shapes and structures of large biological molecules, and thus how they function within cells.
You will investigate the structure of matter in this unit, as well as various types of chemical
bonding.
LEARNING OBJECTIVES
At the end of this module you should be able to:
1. Understand atoms, elements, compounds, and how their properties enable living things.
2. Explain how the atomic number and mass number of an atom can be used to determine
the number of neutrons.
3. Explain how two isotopes of an element are similar, and how they differ.
4. Define the terms energy and potential energy. Explain why electrons in the first
electron shell have less potential energy than electrons in higher electron shells.
5. Distinguish between nonpolar covalent, polar covalent and ionic bonds, and explain how
both strong covalent bonds and weak bonds are essential in living organisms.
6. Explain what is meant by a chemical equilibrium.
CHECK LIST
 Read Chapter 2: The Chemical Context of Life of Campbell and Reece’s Biology, 9th Ed.
 As you are reading, address each of the learning objectives listed above.
 It is recommended that you make flash cards for the terminology list provided. This will
be beneficial for studying for the midterm and final exams later in the semester.
 You may be able to review the PowerPoint Lecture and other resources for this unit.
Refer to your instructor’s notes for more details.
 Discussion Post:
o Respond to Question 12 (Science and Technology) on page 45 of your textbook.
Your response should be a complete paragraph and posted in the Week 1
Discussion Post folder. Read and comment on two of your fellow classmates
responses.
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BIOLOGY SEMESTER ONE
UNIT 2

Question 12. While waiting at an airport, Neil Campbell once overheard
this claim: “It’s paranoid and ignorant to worry about industry or
agriculture contaminating the environment with their chemical wastes.
After all, the stuff is just made from the same atoms that were already
present in our environment.” How would you counter this argument?
 For extra practice try the Self Quiz or Practice Test on the Mastering Biology Website.
To log onto the website, use the access code provided in your textbook. You will also
find other resources, such as downloadable MP3 tutorials for each chapter, a glossary,
and an electronic copy of your text- you can catch up on your reading anywhere!
KEY TERMS
ammonia
anion
atom
atomic mass
atomic nucleus
atomic number
cation
chemical bond
chemical equilibrium
chemical reaction
compound
covalent bond
dalton
double bond
electron
Electron shell
electronegativity
Element
energy
hydrogen bond
ion
ionic bond
ionic compound
isotope
mass number
matter
molecular formula
molecule
neutron
nonpolar covalent bond
nucleus
orbital
polar covalent bond
potential energy
product
proton
radioactive isotope
reactant
salt
single bond
structural formula
Theory
Trace element
valence
valence electron
valence shell
van der Waals interactions
ROOT WORDS TO KNOW
an- = not (anion: a negatively charged ion)
co- = together; -valent = strength (covalent bond: an attraction between atoms that share one
or more pairs of outer-shell electrons)
electro- = electricity (electronegativity: the tendency for an atom to pull electrons toward itself)
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BIOLOGY SEMESTER ONE
UNIT 2
iso- = equal (isotope: an element having the same number of protons and electrons but a
different number of neutrons)
neutr- = neither (neutron: a subatomic particle with a neutral electrical charge)
pro- = before (proton: a subatomic particle with a single positive electrical charge)
SOURCES
Campbell, N. A. (2008). Biology, Eighth Edition. San Francisco: Pearson, Benjamin Cummings.
Coleman, G. J. (1997). The Addison-Wesley Science Handbook. Don Mills, Ontario: Addison-Wesley Publishers
Limited.
Krogh, D. (2000). Biology, A Guide to the Natural World. Upper Saddle River: Prentice Hall.
Pearson Education. (2010). Retrieved 2010, from Mastering Biology : http://session.masteringbiology.com
NANSLO Biology Core Units and Laboratory Experiments
by the North American Network of Science Labs Online,
a collaboration between WICHE, CCCS, and BCcampus
is licensed under a Creative Commons Attribution 3.0 Unported License;
based on a work at rwsl.nic.bc.ca.
Funded by a grant from EDUCAUSE through the Next Generation Learning Challenges.
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