This edition: Proteins: Building Blocks of Life
By examining proteins, Dr. James Lake believes he might find the tracks of evolution, the hereditary path of life back to the first cell. He explains the structure and order of proteins, along with a unique property of DNA and proteins to retain and replicate the genetic code through thousands of years with extraordinary fidelity. In the next segment, a television meteorologist describes how he survived sickle-cell anemia. This often-fatal childhood disease illustrates how one small change in our genetic code causes drastic differences. One sickle-cell gene protects the body against malaria; two sickle-cell genes create a painful and deadly blood disease. Dr. Cage Johnson explains that research in genetic therapy may provide long-term help for patients.
Finally, the program looks at the curious case of slime mold, an organism that is a compelling example of how cells control protein production. Dr. Richard Firtel contrasts how simple prokaryotic cells use operons as “on-off” switches for proteins, while more complex eukaryotic cells differentiate their structures by utilizing proteins in a variety of ways.