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. Actually, that's DNA's main purpose: to make proteins within the cell. These proteins, which include enzymes that do specialized jobs, control the activities of the cell. Different cells have different activities. By controlling protein synthesis within each cell, the genes that make up DNA control the life of the entire organism.

Although the outcome of protein synthesis can be involved and quite complex, its purpose is rather straightforward. The purpose of protein synthesis is simply to create a polypeptide -- a protein made out of a chain of amino acids.

In a hair follicle cell, a protein called keratin is made. Lots of it. Many ribosomes can be working on a single strand of mRNA at once. Protein synthesis isn't a slow process, either. A protein chain 400 amino acids long can be assembled in 20 seconds!

The keratin made by the hair follicle cells makes long fibers. The cells, growing just under the scalp, eventually die, leaving the keratin behind. This keratin, combined with the keratin left by many other cells, emerge from your scalp as hair.

DNA Replication

All Wound Up

Glossary

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