8)What is membrane potential? a.Voltage across a membrane b.Voltage difference a cross a membrane, -50 to -200 mVc.Inside negative compare to outside, cations move inside cell through gatesChapter 111)Explain different ways in which cells communicate with each othera.Physical contactb.Releasing a signal (local or long distance)i.Local: Paracrine and Synapticii.Long Distance: (endocrine) hormone signaling- uses blood2)Describe with examples local and long distance signaling.a.Local- PARACRINE- cell sends out signal, received by all close-target cells with receptors b.Local- SYNAPTIC- nerve cells, transmit signal over synapse that leads directly to other cell that receives signal
c.Long Distance- ENDOCRINE (hormonal) signaling- one cell produces a hormone, sends it out into circulatory system, target cell with received is far away 3)Explain the stages in cell signaling.A.Reception: Cell detects signal with receptor protein inside or on surface of cellB.Transduction: signaling molecules binds to the receptor and activates receptor in some way C.Response: Activated receptor triggers some kind of cellular response 4)Describe with an example how small nonpolar molecules can bring about a response from a cell. 5)Explain in detail the events that follow when a signal molecule (hydrophilic) binds to a G protein receptor. a.Signal (ligand) binds to the receptor, changes shape of the receptor, G protein interacts with receptor and kicks out GDP for GTPb.G protein activates enzyme (Adenylyl Cyclase) which converts ATP into cAMP (by taking away Phosphate)- cAMP then activates first Protein Kinase c.Protein Kinase 1 activates protein kinase 2 by adding phosphate group to it, protein kinase 2 activates protein kinase 3, by giving it a phosphate group, etcd.Then some type of response is caused6)What is the role of second messengers in signal transduction? Explain with reference to cAMP and the phosphorylation cascade.7)State the function of the following enzymes: Kinase, Phosphatase, Adenylyl cyclase, Phosphodiesterase.
- Spring '19
- Energy, Adenosine triphosphate