Describe three steps in the second messenger system (i.e., cell signaling process) after norepinephrine binds to the receptor in an excitatory adrenergic synapse including at least one potential effect on the cell.

If a postsynaptic cell has synapses from five different cells, and three cause EPSPs and two of them cause IPSPs, give an example of a series of depolarizations and hyperpolarizations that would result in the neuron reaching threshold.

When insulin binds to its receptor, the complex is endocytosed into the cell. This is an example of in response to hormone signaling. cAMP activation generating an intracellular receptor activation of a hormone response element receptor down-regulation

Figure 9.8 HER2 is a receptor tyrosine kinase. In 30 percent of human breast cancers, HER2 is permanently activated, resulting in unregulated cell division. Lapatinib, a drug used to treat breast cancer, inhibits HER2 receptor tyrosine kinase autophosphorylation (the process by which the receptor adds phosphates onto itself), thus reducing tumor growth by 50 percent. Besides autophosphorylation, which of the following steps would be inhibited by Lapatinib? Signaling molecule binding, dimerization, and the downstream cellular response. Dimerization, and the downstream cellular response. The downstream cellular response. Phosphatase activity, dimerization, and the downsteam cellular response.

Which of the following is incorrect about pathways activated by G-proteincoupled receptors? a. The extracellular signaling molecule is the first messenger. b. When activated, plasma membrane-bound G protein canswitch on an effector. c. Second messengers enter the nucleus. d. ATP converts to cAMP to activate protein kinases. e. Protein kinases phosphorylate molecules to change cellularactivity.

Answer the following questions regarding conduction of action potentials using the velocities given on p. 100: a. How long would it take for an action potential to travel 0.6 m along the axon of an unmyelinated neuron of the digestive tract? b. How long would it take for an action potential to travel the same distance along the axon of a large myelinated neuron innervating a skeletal muscle? c. Suppose there were two synapses in a 0.6 m nerve tract and the delay at each synapse is 1 msec. How long would it take an action potential and chemical signal to travel the 0.6 m now, for both the myelinated and unmyelinated neurons? d. What if there were five synapses?

Describe several main differences in the communication methods used by the endocrine system and the nervous system.

A newly developed pesticide has been observed to bind to an intracellular hormone receptor. If ingested, residue from this pesticide could disrupt levels of ________. melatonin thyroid hormone growth hormone insulin

Histamine binds to the H1 G-protein-linked receptor to initiate the itchiness and airway constriction associated with an allergic response. If a mutation in the associated G-protein’s alpha subunit prevented the hydrolysis of GTP how would the allergic response change? More severe allergic response compared to normal G-protein signaling. Less severe allergic response compared to normal G-protein signaling. No allergic response. No change compared to normal G-protein signaling.

What effect will a cAMP inhibitor have on a peptide hormone-mediated signaling pathway? It will prevent the hormone from binding its receptor It will prevent activation of a G-protein It will prevent activation of adenylate cyclase It will prevent activation of protein kinases.