THE FUNDAMENTAL UNIT 
4 
T he cell is the fun- 
damental unit of 
life. Your health 
depends on what 
happens within 
the many different types of 
cells that make up your body. 
The health of your cells 
depends, in turn, on the 
function of millions of critical 
molecules. 
Since the mid- 1940’s, 
biomedical researchers have 
made enormous progress in 
identifying and understanding 
these molecules and how they 
interact in many cellular 
processes. Much of this 
research was “basic” — aimed 
simply at learning how living 
systems work. The fundamental 
knowledge developed through 
this research can lead to new 
ways to diagnose, treat, cure, 
or prevent disease. 
A stunning example of how 
basic cell biology research is 
moving toward practical 
application is found in studies 
of the cycle of cell growth and 
division. In recent years, 
many details of the biochemical 
mechanisms involved in the 
normal cell cycle have been 
discovered. Scientists have 
found the cell cycle to be 
regulated by highly complex 
interactions between pairs of 
proteins that belong to two 
general families. Work is 
proceeding at top speed to 
determine all of the many 
molecular interactions and the 
order in which they occur 
during the cell cycle. This work 
is yielding an understanding 
of the normal processes of 
growth and development that 
will, in turn, aid researchers 
seeking to treat diseases in 
which these processes go awry. 
Other scientists are discovering 
direct connections between 
cell cycle regulation and cancer. 
This research is beginning to 
demonstrate the specific role 
of oncogenes, genes that are 
directly involved in the devel- 
opment of cancer, and tumor 
suppressor genes, which are 
involved in cancer when their 
normal inhibitory functions 
are disrupted. 
To help readers understand 
some of the exciting biomedical 
research being conducted 
OF LIFE 
today. Inside the Cell provides 
an overview of the basic facts 
of cell biology. The brochure 
also contains some history of 
key scientific discoveries. 
Many scientists agree that the 
history of modern cell biology 
began with a convergence of 
improved techniques in 
microscopy and biochemistry. 
In the 1950 ’s, as scientists 
working in these fields began 
to collaborate, they started to 
develop our current picture 
of the cell as a complex and 
highly organized entity. 
They found that a typical cell 
is like a miniature body 
containing tiny “organs,” 
called organelles. One organelle 
is the command center, others 
provide the cell with energy, 
while still others manufacture 
proteins and additional 
molecules that the cell needs 
to survive and to communicate 
with the world around it. The 
entire cell is enclosed in a fine 
