Textbook QuestionSome hormones act by a. increasing the synthesis of enzymes, b. converting an inactive enzyme into an active enzyme, c. affecting only specific target organs, d. all of these.331views
Textbook QuestionCyclic AMP functions as a second messenger to (a) build proteins and catalyze specific reactions, (b) activate adenylate cyclase, (c) open ion channels and activate key enzymes in the cytoplasm, (d) bind the hormone–receptor complex to DNA segments.303views
Textbook QuestionHow would blocking the activity of phosphodiesterase (PDE) affect a cell that responds to hormonal stimulation by the cAMP second messenger system?233views
Textbook QuestionA researcher observes that stimulation by a particular hormone induces a marked increase in the activity of G proteins in the target plasma membrane. The hormone being studied is probably (a) a steroid, (b) a peptide, (c) testosterone, (d) estrogen, (e) aldosterone.258views
Multiple ChoiceHormones can bring about substantial physiological changes at very low concentrations. How does this relate to the concept of second messenger systems?336views11rank
Multiple ChoiceYou are studying how a hormone affects a cell and find that when oxytocin binds the receptor, the intracellular CaCaCa2^22+^++ concentration increases. Based on this information, what could you logically conclude about this cell and hormone?307views12rank
Multiple ChoicecAMP, IP3IP_3IP3, and DAG are all molecules that are used as secondary messengers. Which statement below correctly identifies a difference between the pathways in which they are found?274views6rank
Multiple ChoiceWhich of the following describes a hormone that CANNOT exhibit its full effect without the presence of another hormone?820views