1. Chapter 6-10 AP Biology

2. Define phagocytosis and pinocytosis. What does it mean for a cell to have a concentration gradient?

3. Signal Transduction Pathway- a specific cellular response as a result of a received cellular signal.

4. Local Regulators- influence cells in the nearby vicinity. Paracrine Signaling- broad range- can communicate with many cells. Synaptic Signaling- occurs in the nervous system (more specific)

5. Hormones- chemicals that aide in long distance signaling- released by specialized cells and travel in the blood stream.

6. Reception- the target cell’s detection of a chemical signaling molecule. (when the molecule binds to the receptor protein). Transduction- the change that occurs on the protein due to the receptor binding. Response- transduced signal triggers a specific cellular response.

7. G Protein Coupled Receptors (GPCRs)- signaling molecule binds to GPCR which activates it and changes its shape. GPCR then binds an inactive G protein causing GDP to convert to GTP, activating the G protein. Protein binds to enzyme, activating it- triggering the next step in a cellular response.

8. Receptor Tyrosine Kinases (RTKs)- transfer phosphates from ATP to the amino acid tyrosine.

9. Ion Channel Receptors- includes a region that acts as a fate when the receptor changes shape. Gate can open or close to allow flow of specific ions.

10. Intracellular Receptors- found in the cytoplasm or nucleus of target cells.

11. What are the three stages of cell signaling? What are the two types of local signaling? Which is the strongest? Hint: When a signal is transmitted to numerous molecules, it is more amplified because it activates more than one molecule at the end of a pathway. How are long-distance signals sent? What are the three main types of transmembrane receptors?

12. Protein Kinase- enzyme that transfers phosphate groups from ATP to a protein. Phosphorylation- adding a phosphate (which many times activates the protein)

14. Protein Phosphatase- enzyme that rapidly remove phosphate groups from proteins, a process called dephosphorylation. Usually inactivates protein kinases and help turn off signal transduction pathway. Makes protein kinases available for reuse.

15. Second Messengers- small, water-soluble, non-protein molecules/ions involved in signaling pathways. Cyclic AMP (cAMP)- (cyclic adenosine monophosphate)- ATP is converted to cAMP by an enzyme (adenylyl cyclase) in the plasma membrane in response to an extracellular signal (usually a hormone). Phosphodiesterase- reduces cAMP to AMP

16. cAMP usually activates protein kinase A which phosphorylates other molecules in the signal transduction pathway.

17. Calcium (Ca 2+ ) Ion- calcium pumps actively transport calcium ions from the cytoplasm out of the cell or into the ER.

19. Signaling pathway may regulate protein activity or synthesis.