BIO 201 Lecture Notes - Lecture 14: Cell Signaling, Autocrine Signalling, Glycogen Phosphorylase
3 Apr 2017
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Document Summary
Cell signaling- cells must be able to respond to signals from both outside and inside the organism and their response should benefit the organism or the population. The signal itself (ligand) is produced by a sender and received by a. Recipient. signaling modes are defined by distance between sender and. Autocrine- self signaling : sender and recipient are the same cell or group of cells. Juxtacrine- signaling molecule is attached to sender cell or is part of ecm; does not diffuse. Paracrine: signaling molecule can diffuse one or several cell diameters away to nearby recipient cells. Advantages: communication with more cells than juxtacine; fast. Endocrine/ hormonal: signaling molecule is secreted into the bloodstream, allowing it to diffuse throughout the body. Advantages: coordinates behavior of all tissues in the body. Ligand-gated ion channel: neuron releases neurotransmitter ach which binds to nach receptor on muscle. Na+ diffuses down its concentration gradient into cytoplasm. Na+ triggers downstream events that lead to muscle contraction.
