Good Cells Gone Bad
TEACHER WORKSHEET
10-12
OBJECTIVES
1. Identify the structure and function of a “normal cell” versus a “cancer cell”
2. Understand the mechanisms by which normal cells can become cancerous
BACKGROUND INFORMATION
Cells are the basic unit of structure and function for all living things. As cells grow and divide, they
arrange themselves in a particular way to form tissues. All tissues perform functions in our body.
Healthy or normal cells can:
• Make proteins or “worker molecules” required by the body
• Make their own energy using oxygen
• Divide to make new cells
• Cells respond to signals to divide
• Grow and multiply in a controlled fashion and know where they belong in the body
• Die after a specific number of divisions
Cancer occurs when cells no longer function normally. Cancer cells grow and divide in an
uncontrolled way. The cells take on new characteristics that allow them to behave in an
undesirable manner. In cancer cells:
• Proteins or “worker molecules” can be missing or present in unnecessary amounts.
Proteins may not be able to function normally to stop cell growth or they may make the cell
grow faster.
• Cells do not need signals to keep growing
• Energy is made without oxygen
• Growth is not regulated so the cancer cells grow rapidly and out of control. Cells do not
mature and don’t grow to the normal size.
• Changes occur that allow the cells to go places in the body where they do not belong
• An immortal nature allows the cancer cells to live much longer than normal and do not die
Cell structure also differs between a normal healthy cell and a cancer cell as illustrated below.
© Harper, A., and Nickels, K. 2008. Queensland University of Technology.
Good Cells Gone Bad
TEACHER WORKSHEET
10-12
Cancer is a word used to describe many diseases, all of which are characterised by the
uncontrolled growth and spread of cells. These cells are abnormal and do not behave or function
like normal cells. Normal cells grow and multiply in a controlled way to replace old or dead cells.
Cancer cells grow and multiply uncontrollably. They continue growing and dividing regardless of
whether or not new cells are needed.
This uncontrolled growth of cancer cells results in the formation of malignant tumors. These tumors
can grow slowly or rapidly. The tumors can invade and spread to other tissues and organs in our
bodies, destroying normal cells along the way. When cancer spreads it is called metastasis.
There are more than 100 kinds of cancer. Cancers are usually named for the body tissue from
which the cancer cell was developed.
Cancer develops when a cell becomes abnormal. What causes the cell to become abnormal is
often not understood. Many factors have been found to be cancer-causing. They include tobacco
products, exposure to some chemicals, and excessive exposure to sunlight.
Provide students with the following materials:
These items represent features/characteristics of the cell and not organelles.
Materials
What it represents
Zip lock bags (small, medium and large)
Cell membrane
Ribbon
DNA
Small container
Nucleui
Different sized beads
Necleoli
Paper clips
Proteins or “worker molecules”
Stamp
Communication network
Candle
Finite life-span
Match
Energy source, burning of oxygen in process of
respiration
Sugar packet
Use of glycolysis
© Harper, A., and Nickels, K. 2008. Queensland University of Technology.
Good Cells Gone Bad
TEACHER WORKSHEET
10-12
Students should put the cells together in the following way:
Normal cell contents
What it represents
Zip-lock bags - large
Normal cells of the same type are the same
size
1x Small container
Single nucleus
1x Bead in small container
Single Nucleolus
Ribbon contained within small container
representing nucleus
DNA or the ”information molecule”
Thumbtacks/paper clips
Proteins or “worker molecules”
Stamp
Normal cells respond to signals telling them
when to divide or when to die
Candle
Limited life-span of normal cells
Match
Cell’s energy source, normal cells burn oxygen
using a process called respiration
Cancer cell contents
What it represents
Zip-lock bags of different sizes
Cells are not uniform in size in cancer. They are
often smaller as they don’t have time to grow
before they start dividing again.
Multiple containers
Multiple nuclei
Multiple larger sized beads
Multiple and large nucleoli
Ribbon contained within small container
representing nucleus
DNA or the “information molecule” has 2 black
lines indicating mutations/changes
Thumbtacks/paper clips (bent or altered)
These changes in the DNA create changes in
the proteins
No stamp
Stamp is missing representing the fact that
cancer need signals to keep dividing and ignore
signals telling the cell to die
No candle
Characterises the immortal nature of cancer
cells
No match
Sugar
Cancer cells often switch to the less efficient
process of glycolysis to make energy without
oxygen (anaerobic)
CURRICULUM
Science 21
LS2: DNA encodes the information needed for cells and organisms to replicate.
Senior Biology Key Ideas
10. Malfunctioning in one system or part of a system may affect the whole organism
REFERENCES
1. Arizona Cancer Centre. 2004. Good Cells gone bad.
http://coep.pharmacy.arizona.edu/curriculum/goodcells/good_cells.html. (accessed 27/03/08).
© Harper, A., and Nickels, K. 2008. Queensland University of Technology.