How Scientists Are Creating Alternate Life Forms Mon.
Cells are the smallest things that can be alive.
Like a chemical instruction manual for life, DNA tells the factory which of 20 amino acids to use when building a particular protein. DNA has a remarkably limited vocabulary, one that is the same in the cells of bacteria as it is in humans. This genetic language is designed using four basic chemicals, which biologists represent with four letters. Each necessary instruction is spelled out in a series of single words, each using just three of these four letters. This caused the factory to make mistakes.