Your friend is studying mouse fur color and has identified t…

Your friend is studying mouse fur color and has identified the GPCR responsible for determining fur color, as well as the extracellular signal that activates it. She observes that adding the signal to pigment cells (which produce pigment for fur color) increases cAMP levels. Inspired by this discovery, she starts a biotech company that isolates additional components of the signaling pathway involved in fur color determination. Using transgenic mouse technology, the company creates mice with targeted genetic modifications to investigate the role of specific proteins in fur color. The following results are obtained: a) Normal mice have beige (light brown) fur.b) Mice lacking the extracellular signal have white fur.c) Mice lacking the GPCR have white fur.d) Mice lacking cAMP phosphodiesterase have dark brown fur. Questions Describe the signaling pathway activated to produce beige fur color. Explain the molecular mechanisms underlying results b, c, and d: Result b: Mice lacking the extracellular signal have white fur. Result c: Mice lacking the GPCR have white fur. Result d: Mice lacking cAMP phosphodiesterase have dark brown fur What fur color do you predict for mice with a defective Gs α subunit that cannot hydrolyze GTP? Why? What would be the fur color of mice with defective Gi α subunits that cannot hydrolyze GTP? Why?  

One of the biochemical tests performed by the clinical lab o…

One of the biochemical tests performed by the clinical lab on this unknown bacterial sample is shown in the photo. This test was incubated at 37 degrees Celsius for 30 hours.  What does this tell you about the metabolism of this specimen?  (select all that apply)