CELLULAR FORM AND FUNCTION
Chapter 3 investigates the next level in the organizational hierarchy of the organism: the cell’s organelles,
membranes, cytoskeleton, and inclusions. These cell parts are organized from aggregations of different
types of polymers: carbohydrates, lipids, proteins, and nucleic acids. The chapter encompasses a discussion
of the functions of each of the major organelles as well as that of the plasma membrane. The author details
many aspects of the functions of the cell membrane, especially cross-membrane transport mechanisms.
Here are some concepts that students should have a better understanding of after reading this chapter:
the historical development of the cell theory;
modern insights into the cell theory as these have accompanied technological improvements;
the components of the plasma membrane and their functions, especially phospholipids and
the nature and functions of the glycocalyx, cytoskeleton, and cell surface extensions;
passive mechanisms for cross-membrane transport particularly diffusion, osmosis, channels,
facilitated diffusion, and carriers;
the concept of second messengers is introduced;
active transport mechanisms, including symport and antiport systems, cotransport, phagocytosis,
pinocytosis, and exocytosis;
and the functions in brief of the organelles such as the nucleus, ribosomes, Golgi complex,
lysosomes, mitochondria, and centrioles.
Topics for Discussion
What are the different patterns of cross-membrane transportation?
How will the particular cross-membrane transport mechanism vary depending upon whether a material
is water soluble, fat soluble, or insoluble?
List some everyday examples of diffusion.
Why is it that some people call the cell membrane the cell’s “window to the world”?
Compare and contrast the uses of electron and light microscopes. Ask the students to ponder how our
worldview would be different had these inventions never been made.
Some blood parasites hide from the immune system by mimicking the glycocalyx.
Balman, A. and R.J. Akhurst. 2004. Dangerous liaisons.
428: 271–272. Growth factors and cancer.
Bayley, H. 1997. Building doors into cells.
. 277 (3): 62–67. This article is about using artificially-
inserted pores into cell membranes.
Deretic, P. and D.J. Kliansky. 2008. How cells clean house.
. 298 (5): 74–81. The main idea here is
autophagy or the methods by which cells clean up disused parts of the cell. The role of lysosomes and the
application of these events to human health are also discussed.
Foulkes, W.D. 2007. p53—master and commander.