Page 102 - Radiation Safety

All living cells that are capable of reproducing themselves have

certain basic features in common:

• A membrane, which envelopes the cell, separates its interior

from the surroundings, strictly controls what moves in and out

and maintains the electrical potential of the cell,

• A salty cytoplasm (the substance which makes up most of the

cell volume)

• DNA, the hereditary material of genes, which guide the

operations of the cell.

• RNA, through which DNA instructions are expressed.

• Enzymes, protein machinery and a variety of bio-molecules.