AP Biology Reading Guide Chapter 15 and 16: Regulation of Gene Expression & Development, Stem Cells and Cancer

AP Biology Reading Guide Chapter 15 and 16: Regulation of Gene Expression & Development, Stem Cells and Cancer. What are the two main ways of controlling metabolism in bacterial cells? Feedback inhibition: when the end product of a metabolic pathway goes back and inhibits the one of the enzymes that is active in that pathway. This stops the production of that product. Regulation of gene expression: mechanisms that are used by cells to increase or decrease the production of specific gene products. 3. Feedback inhibition is a recurring mechanism throughout biological systems. In the case of E. coli regulating tryptophan synthesis, is it positive or negative inhibition? Explain your choice. E coli is negative inhibition. It involves an operon being switched off by a protein. 4. Operons have not been found in eukaryotic cells, and the genes coding for the enzymes of a particular metabolic pathway are often scattered over different chromosomes. What is a plausible mechanism for the coordination of gene expression? A specific combination of controls respond to the same signal. This activates different genes. 5. What is a promoter? The region of DNA where RNA polymerase can get on to. 6. What is the operator? What does it do? The “switch” that controls related genes. 7. What is an operon? A segment of DNA that has an operator, promoter, and genes being controlled. 8. List the three components of an operon, and explain the role of each one.