In the epinephrine pathway, an inhibitor of phosphodiesterase activity would have which of the following effects? A. block the activation of protein kinase A B. block the activation of G proteins in response to epinephrine binding to its receptor C. prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm D. block the response of epinephrine

C). prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm

Explanation: In the epinephrine pathway, binding of epinephrine to its receptor triggers a conformational change in the receptor and the interaction of the receptor with its associated Gs protein. This interaction causes the replacement of GDP bound to Gs protein with GTP thus activating the Gs protein. The activation of the Gs protein causes the alpha subunit of the Gs protein to dissociate and move to adenylyl cyclase, another membrane protein in the pathway. The association of the alpha subunit of the Gs protein with adenylyl cyclase activates adenylyl cyclase which in turn catalyzes the synthesis of cyclic AMP (cAMP) a second messenger. cAMP is quickly degraded to 5'-AMP by an enzyme phosphodiesterase. Inhibition of the activity of phosphodiesterase will increase the half life and the cytoplasmic level of cAMP thus potentiating the action of epinephrine.

events in order:

1.       vishnu schist

2. zoroaster granite

3. bass limestone

4. hakatar   shale

5. igneous intrusion

6. shinumo quartzite

7. dox sandstone

8. tapeats limestone

9. bright angel shale

10. muav limestone

11. temple butte limestone

12. redwall limestone  

nonconformity

answer: the unkar group shows angular unconformity because the layers are turned at angle.

unconformity

answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.

disconformity

answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.