Biology 1107 Final Exam Study Guide (University Of Connecticut) 2024

Biology 1107 Final Exam Study Guide (University Of Connecticut) 2024 1. Explain how cells communicate via direct contact, local signaling, and long- distance signaling. a. Direct contact: channels that connect the cytoplasms of two different cells. Rapid, involves ions or small particles passing from one cell to another i. Gap junctions - animal cells, involves tunnels for electrical synapses 1. Ions pass from one neuron to another, neuro ii. Plasmodesmata: facilitates communication in plant cells through direct contact iii. Cell-cell recognition and docking molecules 1. Recognize other membrane bound surface molecules 2. Allow the transfer of things from one cell to another b. Local signaling- autocrine or paracrine, i. Autocrine- signal is released and received by the same cell 1. Monitors the amount of local regulator that diffuses through the extracellular space, can limit the production of the regulator ii. Paracrine- local regulator is released and diffuses through the extracellular space and binds to receptors on other cells 1. At a chemical synapse, chemical signals called neurotransmitters pass from one neuron to receptor on another neuron c. Long distance signaling- just like paracrine but is between cells that are farther apart i. Circulatory system can be used to transport the signal ii. Hormones, first messenger and ligands are all long distance molecules iii. Can be lipid or protein based iv. Move through extracellular fluid through diffusion, can have assistance or carrier proteins that protect them from being degraded 2. Be able to explain the steps of signal transduction. a. First messenger / ligand - i. Nothing happens unless the target cell receives the ligand at the receptor