How does your body know when to make proteins? Gene Regulation How does your body know when to make proteins?

Gene Regulation Terms RNA polymerase – The enzyme used to transcribe a gene. lac Operon – Section of DNA containing binding sites for the promoter, operator, and the lactase gene.

Gene Regulation Terms Lactase – The enzyme used to break down the sugar in milk Lactose – The sugar found in milk

Gene Regulation Terms Repressor Protein – Prevents RNA polymerase from making the mRNA strand Operator – Section of the DNA the repressor binds to. Promoter – Section of the DNA that RNA polymerase binds to

When NO Lactose Present: RNA Polymerase Repressor protein Is lactase made? WHY? NO, because the repressor protein is blocking RNA polymerase from copying the gene for lactase

When Lactose IS Present: What happens to the repressor when lactose is present? Lactose fits into the active site of the repressor protein, which causes it to release from the operator. RNA polymerase can copy the gene.

Lactose is present: mRNA is made mRNA strand that will be translated to make Lactase.

And Back to No Lactose Present: RNA Polymerase Repressor protein What will happen after all the lactose is broken down? The repressor protein will grab onto the operator stopping the production of lactase again.

Ameoba Sisters video https://www.youtube.com/watch?v=h_1QLdtF8d0

lac Operon from Dolan DNA Learning Center http://teachercenter.insidecancer.org/p/920

Eukaryote and Prokaryote Gene Regulation: Operons ___________ generally are not found in eukaryotes Most eukaryotic genes are controlled ___________ and have __________ sequences that are much more ______ than those of the lac operon. Individually Regulatory Complex

Eukaryote and Prokaryote Gene Regulation: A typical feature in a eukaryotic cell is the presence of a gene sequence about 30 base pairs long with a sequence of ___________ or ___________. This sequence is found directly before the starting point for __________________. This region is known as the _______ TATATA TATAAA RNA Polymerase TATA Box

Amoeba Sisters https://www.youtube.com/watch?v=h_1QLdtF8d0