Problem
I. Cell surface receptors lead to many possible responses. These responses often involve protein kinases. Define a protein kinase.
II. What is a protein phosphatase?
III. What is the general rule for how phosphorylation affects proteins?
IV. Define second messenger,and give two examples.
V. Describe a step-by-step process involving signal transduction, cyclic AMP, and protein kinase A. The final step involves turning ON proteins that will cause a cell response.
VI. Where in the cell is the calcium concentration low, and where is it high?
VII. Provide a step-by-step process involving calcium and signal transduction (do not include phospholipase, phosphatidyl inositol, or DAG). The final step involves turning ON proteins that will cause a cell response.
VIII. What is meant by "amplification of a signal"?
IX. How can a small amount of signal produce a large cellular response?