BIOL 1201: Final Exam Questions with Verified Solutions

BIOL 1201: Final Exam Questions with Verified Solutions What are the three types of cell signaling? ✔✔1. Direct Contact 2. Local 3. Distant Describe direct contact cell signaling and some examples. ✔✔One cell actually physically touches another i.e. Gap Junctions (diffusion of signals through a plasma membrane), Plasmodesmata (diffusion of signals through a plasma membrane), and Cell -Cell Rec ognition (one cell have a type of signal molecule while the other cell has a receptor, and they bind and create a response) Describe local cell signaling and some examples. ✔✔Cells are signaling and the signal is released into the extracellular liquid; af fects cells in the area i.e. Paracrine (one cell is releasing signal molecules, diffusing into the area, affecting the cells nearby, for example, a wound) and Synaptic (space between neurons where neurotransmitters diffuse across the synapsis) Describe distant cell signaling and some examples. ✔✔Signals cells in another part of the body i.e. Endocrine System (hormones are sent all over the body to initiate a response) A compound that is secreted in one part of the body and travels through the bloodstre am to another part of the body where it has an effect is called a(n) A. Receptor protein B. Hormone C. Transmitter D. Activator ✔✔B. Hormone When a platelet contacts a damaged blood vessel, it is stimulated to release thromboxane A2. Thromboxane A2 in tu rn stimulates a vascular spasm and attracts additional platelets to the injured site. In this example, thromboxane A2 is acting as ____________. A. direct contact signal molecule B. local signal molecule C. distant signal molecule ✔✔B. local signal molecule What are the three steps of cell signaling? ✔✔1. Reception 2. Transduction 3. Response Where are receptors located? ✔✔plasma membrane and cytoplasm Most receptors are _____________ attached to the pl asma membrane. ✔✔proteins Since receptors are proteins, what does that tell us about the specificity of the receptors? ✔✔Since receptors are proteins, then they are highly specific and will only bind to a specific signal molecule. Which molecules determi ne the tissue specificity of hormones? A. Receptors. B. Hormone -response elements. C. Second messengers. D. Agonists. ✔✔A. Receptors. Assuming there are a 100 different signaling molecules in your body. What is the minimum number of receptors that your b ody needs to make? A. 1 B. 10 C. 100 D. 1000 E. 1000000 ✔✔C. 100 When receptors are bound to the plasma membrane, what does this tell us about the properties of the signal molecules? ✔✔Since the receptors are embedded in the plasma membrane, then the signal molecules for those receptors are not permeable to the membrane and need help to pass through the membrane.