Bio- Gene Regulation

Prokaryotic Gene Regulation

• DNA-binding proteins regulate genes by controlling conscription

• one key to gene transcription is the organization of genes

  • operons

Lac operon

• no lactose= lac genes turn off= no transcription

• lactose is needed to bind

Promoters and Operators

• Promoters- where the RNA polymerase binds

• operators- where repressor protein binds

• lac repressor gene codes for the repressor protein

  • blocks transcription

With Lactose

• lactose added to medium

• diffuses into the cell and attaches to lac repressor

Eukaryotic Gene regulation

• contains enhancer and TATA box

• TATA box- DNA series of Ts and As

  • helps bind to polymerase

• Enhancers- transcription factors

  • made as needed

Cell Specialization

• made by complex gene regulation

• wouldn’t be possible without regulation

Genetic Control of Development

• regulating gene expression is important in developing multicellular organisms

• each specialized cell types found in the adult originates from the same fertilized egg

Homeotic, Homeobox, Hox Genes

• Homeotic- regulate organ development

• Homeobox- code for transcription factors

• Hox- determines the identity of body segments