So how does protein synthesis make hair? If you've looked at the activity (or even the text version of the activity), you know how a section of DNA instructs a cell how to make a protein.

Why is this definition now considered overly simplistic ... breaks apart and then re-forms itself at certain points in protein synthesis. Specifically, the sections of DNA that encode protein ...

This process of protein synthesis occurs in two stages - transcription and translation. When a gene is to be expressed, the base sequence of DNA is copied or transcribed into mRNA (messenger RNA).