Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from
A) applying a molecule of hormone X to the extracellular fluid surrounding the cell.
B) injecting a molecule of hormone X into the cytoplasm of the cell.
C) applying a molecule of cAMP to the extracellular fluid surrounding the cell.
D) injecting a molecule of cAMP into the cytoplasm of the cell.
E) injecting a molecule of activated, cAMP-dependent protein kinase into the cytoplasm of the cell.
Dividing bacterial cells
Common structural features of bacterial cells
Stem cells in late development
Major glands of the human endocrine system
The Conduction System
A system absorbs 623 J of heat while doing 457 J of work. What is the value of U?