Biology 463 Student Name answer. Read carefully. Write legibly. Be concise. Be specific. Provide the best l. Which type of cell signaling travels the greatest distance? paracrine signaling contact-dependent signaling endocrine signaling (c) (d) None of the above 2. Which of the following is true? (a) Nucleotides and amino acids can act as extracellular signal molecules. (b) gene transcription (c) Some signal molecules are transmembrane proteins. (d) All of the above. 3-6. Which process in each pair is likely to occur more rapidly in response to an extracellular signal? 3. (a) changes in cell movement OR (b) changes in gene expression 4. (a) changes in enzyme activity OR (b) changes in protein synthesis 5. (a) changes in mRNA levels OR (b) changes in protein conformation 7. Which of the following statements is true? (a) Extracellular signal molecules that are hydrophobic bind to a cell surface receptor. All extracellular si molecules must be transported by their receptor across the plasma membrane into the cytosol (c) A cell-surface receptor capable of binding only one type of signal molecule can mediate different responses in different target cells. ll of the above. 8. Which of the following statements about molecular switches is true? (a) Phosphatases remove the phosphate from GTP on ding proteins, turning them off (b) Protein phosphatases transfer the terminal phosphate from GTP a protein. (c) Serine/threonine kinases are the most common types of protein kinase (d) A GTP-binding protein exchanges its bound GTP for GDP to become activated. 9. The following happens when acel-surface receptor activates a G protein. (a) The B subunit exchanges its bound GDP for GTP. (b) The GDP bound to the a subunit is phosphorylated to form bound GTP. (c) The a subunit exchanges its bound GTP forGDP. (d) None of the above. 10. You are interested in how cyclic-AMP-dependent protein kinase A (PKA)functions to affect memory. It is known that in the cells you are studying PKA works via a GPCR pathway. Furthermore, activated PKA phosphorylates the transcriptional regulator called that then activates transcription of the gene Brainy. Which situation below will most likely lead to an increase n Brai my transcription? (a) mutation in the Nerd gene that produces a that cannot be phosphorylated by PKA (b) a mutation in the gene that encodes CAMP phosphodiesterase that makes the enzyme inactive (c) a mutation in the gene that encodes adenylyl cyclase that renders the enzyme unable to interact with the a subunit of the G protein (d) None of the above.