Answers to the Ch16 practice questions
1. endocrine, contact-dependent, paracrine, neuronal, receptor
2. 3 paracrine signaling
1 contact-dependent signaling
4 endocrine signaling
changes in cell secretion
B. changes in protein phosphorylation
C. changes in membrane potential
An answer involving the modification of existing cell components is correct. For example,
phosphorylation, and lipid cleavage are correct answers.
Alterations in gene expression occur slowly.
Modification of existing cellular components can be achieved quickly, whereas responses
requiring changes in gene expression take much longer, because the genes will need to be
transcribed, the mRNAs will need to be translated, and the proteins should accumulate.
10. receptors, effector, amplify, integrate, GTP-binding, protein kinases, protein phosphatases
11. Ion-channel-coupled receptors; G-protein-coupled receptors; enzyme-coupled receptors.
13. seven, three, Two, GDP, GTP, GTPase, chlera toxin
A. No. Each signaling molecule activates only one receptor molecule.
B. Yes. Each activated GPCR stimulate many G-protein molecules.